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1998 SeaDoo Racing Handbook

1. nne 03 19 ROTARY VALVE HUC 03 24 ROTARY VALVE IDENTIFICATION sius puORU 03 26 CYLINDER coni E 03 28 787 ENGINE MODIFICATIONS 03 32 947 ENGINE MODIFICATIONS da une Idi EAR UE rius paite 03 36 ENGINE LEAKAGE T D uiia disease 03 39 ENGINE LEAKAGE DIAGNOSTIC FLOW nennen hne nnn nnn 03 44 CHANKSHAFTI INSPECID IN 03 45 ENGINE BREAK IN PROCEDURE uu aa vase rS 03 48 FUNCTION OF AN EXHAUST SYSTEM U 03 49 WATER FLOW REGULATOR VALVE n 03 50 FUNCTHON OF THE COOLING 03 53 SYSTEM E E E 03 58 SPARK PLUG INFORMATION T 03 66 MIKUNI BN CARBURETORS M N 03 68 RACING ENGINE PREPARATION 5 03 78 USING RADAR GUN FOR 03 80 03 1 www SeaDooManuals net SECTION 03 ENGINE PREPARATION ENGINE TUNING CAUTIONS A few items to keep in mind when preparing your Ignition timing may need to be altered from stan dard timing specifications to achieve maximum power output
2. I ien ME 03 16 CALCULATING MACHINING CYLINDER HEAD HEIGHT VERSUS COMBUSTION CHAMBER VOLUME 03 17 OCTANE REQUIREMENTS FOR ROTAX eese nne nnne nnns 03 17 HAVE WVABVE OPBERAJTIODL M Im Id DNE EMI 03 17 FUNCTION OF THE ROTARY VALVE INTAKE 5 nennt 03 19 ROTARY bicERuUcm S 03 24 ROTARY VALVE IDENTIFICATION 03 26 CYLINDER PORTING NIAPS uu l u u 03 28 787 ENGINE MODIFICATION S n E 03 32 947 ENGINE MODIFICATIONS saura ira IM mU 03 36 ENGINE LEAKAGE TEST E Eaa 03 39 ENGINE LEAKAGE DIAGNOSTIC FLOW CHART sees nnne nennt 03 44 CRANKS AFTINSPEC TION eate PHI REFUS 4 03 45 ENGINE BREAK IN ence eee eens cen 03 48 FUNCTION OF EXHAUST SYSTEM U 03 49 WATER FLOW REGULATOR VALVE 03 50 FUNCTION OF THE COOLING SYSTEM MUNDI E 03 53 I NITO YO 03 58 SPARK PLUG INFORMATION 03 66 MIKUNI BN CARBURETORS pen 03 68 RACING ENGINE PREPARATION 50
3. 02 3 CONCEPTUM PAINTING PROCEDURE ull 02 3 DELTA PAINTING PROCEDURE u d xau UU ado 02 4 SEA DOO PAINT CODES __ 02 5 STORAGE COVER PAINT CODES ud tuna REMEDIUM 02 6 ENGINE FAINT CODE u P 02 6 EXHAUST SYSTEM PAINT CODE M S IE 02 6 MODELS WITH CORRESPONDING BODY HULL PAINT CODES eese 02 6 SEALING OF BODY COMPONENTS 02 8 HULL AND BODY MAINTENANCE TES ici FUE 02 8 Pe VGA VV MICE iiber 02 8 vae IN duy 02 8 I www SeaDooManuals net TABLE OF CONTENTS SECTION 03 ENGINE PREPARATION ENGINE TUNING CAUTIONS 03 2 BASIC ENGINE TERMINOLOGY nnn 03 2 BASIC ENGINE COMPONENTS 03 3 ENGINE CONFIGURATION 03 7 BASIC ENGINE Ve f 03 8 CONIBUSTION PROCE O9 __ _ _ _ _ _ ____ _ _ DE 03 10 SOLEA A 03 13 COMBUSTION CHAMBER VOLUME 50 03 14 CALCULATING THE COMPRESSION MN IM REDIT Pasta
4. adid peuni peau JO JUIOd 1edeeq jo 1urod JOSUOS INALSAS SNISN3 288 03 54 www SeaDooManuals net N gt SECTION 03 ENGINE PREPARATION f a iz 2 1 AM A 24 lt A 4 657 AND 657 ENGINE COOLING SYSTEM LO v E 2 Uppermost point of engine cylinder head allows bleeding 9 Pressure zone Temperature sensor activates monitoring beeper when 10 Engine water inlet hose temperature exceeds 96 99 C 205 210 F 11 Tuned pipe bleed hose injects water into muffler to cool exhaust Calibrated cylinder head limits water flow components GTX model Engine water outlet hose 12 Lowest point of circuit allows draining whenever engine 15 SPX model stopped Fitting spigot 13 Water injected directly into exhaust gas for noise reduction and Cooling System Indicator s CSI Small stream of water flows performance improvement out of bleed outlet s located near stern eyelet 14 Fresh water flows through tuned pipe and manifold water Jackets Calibrated outlet fittings limit water flow 15 Uppermost point of circuit tuned pipe allows bleeding 03 55 www SeaDooManuals net SECTION 03 ENGINE PREPARATION 5 03101 9102 eJnssaJg
5. 03 78 USING A RADAR GUN FOR TUNING 03 80 IV www SeaDooManuals net TABLE OF CONTENTS SECTION 04 PROPULSION SYSTEM BASIC FUNCTIONS OF Ti S Y C 04 2 PROPULSION SYSTEM ANALYSIS u UU UU INN CE 04 2 VENTILATION AIR LEAK ___ ___ 04 3 CAVI EATON 04 4 VIPE LCE Fea E 04 4 IMPELLER __________ UR EB SE 04 7 IMPELLER SPECIFICATIONS AND BOOT APPLICATIONS 04 9 IMPELLER PHCA CHAR 04 10 ENGINE JET PUMP 04 11 FUNCTIONS OF THE VARIABLE TRIM SYSTEM VTS eee Henn 04 12 PROPULSION SYSTEM cau a run in us un KHOE FS En CURE EH EE 04 13 SECTION 05 MISCELLANEOUS EQUIVALENT WEIGHTS AND MEASURES CHART ku bi Eu Rn 05 2 GLOSSARY OF TERMS PERSONNAL WATERCRAFT RACING 05 3 gr c 05 4 aj eAPSBRGICH 05 5 AFTERMARK
6. smm Stroke 03 30 www SeaDooManuals net SECTION 03 ENGINE PREPARATION Porting Map for the 1996 through 1998 Engines ENGINE TYP MODEL YEAR 2 Exhaust port height 38 70 mm Exhaust port width 69 30 mm Exhaust port height bottom to top 40 50 mm Boost port height 61 30 mm Boost port width 18 60 mm Boost port length bottom to top 87 20 mm T T Main transfer height 1 49 5 mm 51 8 mm 56 mm 61 20 mm 2 49 5mm 51 8 mm 56 mm 61 10 mm Main transfer width at bottom T3 20 0mm 25 0 mm 28 7 mm 30 60 mm 14 21 0 mm 20 0 mm 22 8 mm 29 80 mm Total cylinder height 109 6 mm 114 3 mm 122 0 mm 124 50 mm Exhaust outlet height at Y type Exhaust outlet width at Y type Combustion chamber volume with 0 012 in base 45 30 cc gasket Uncorrected compression ratio Bore Stroke 03 31 www SeaDooManuals net SECTION 03 ENGINE PREPARATION 787 ENGINE MODIFICATIONS Superstock Modifications In the following pages are recommended for modifying Superstock race craft In addition to the modifications to the original equipment parts shown other modifications are necessary These additional modifications include but are not limit ed to Dual 46mm carburetors Mikuni 72 liter per hour fuel pump Primer kit Modified or aftermarket intake manifold Free flowing flame arresters Modified or aftermarket exhaust system Ignition enhancer Aftermarke
7. insurance company social security number employer s name and phone number PREPARING FOR A SAFETY INSPECTION On race day you must have your watercraft safety inspected The Technical Inspector will thoroughly check the watercraft for safety requirements The requirements vary slightly from one sanctioning body to another The IJSBA is the most stringent in their requirements The following is a list of items the inspector will evaluate if the race is sanctioned by the IJSBA 1 Boat numbers and backgrounds must be of the correct size color coordinated and placed in the correct location on the watercraft On Sea Doo watercraft the numbers are required to be on the upper portion of the front deck as close to the storage compartment as possible This allows ease of visibility for the scoring staff If the numbers can not be easily read you may be required to relocate them The background and boat number colors are determined by your ex perience level Novice Black Numbers Orange Background Expert Black Numbers Yellow Background Pro Black Numbers White Background www SeaDooManuals net SECTION 01 GENERAL RACING INFORMATION Your boat numbers must be at minimum 18 cm 7 in high and must be spaced 13 mm 0 5 in apart Backgrounds must be 20 cm 8 in high and 15 36 cm 6 14 in wide depending on the amount of numbers you run Boat numbers will be assigned to you by the IJSBA or in regional events yo
8. 16 Verify that all gauges are functioning correctly 17 Test ride the watercraft and perform any ad justments before leaving for the race site 18 Flush the cooling system to insure cleanliness and maximum cooling system efficiency 19 Make sure that all fuel lines are zip tied or clamped and all water lines are clamped tight ly MAINTENANCE BETWEEN RACES The following items should be checked between races 1 Remove the spark plugs and check their condi tion change if necessary 2 Check the exhaust system for leaks and tight ness 3 Check throttle operation make sure full throttle is being attained 4 Visually inspect all inner hull components for secure mounting and proper operation 5 Adjust fuel and oil levels as needed 6 Visually inspect the hull for external damage or punctures repair as necessary NOTE Irreparable hull damage which occurs dur Ing a race 15 the only reason a racer is allowed to run a different boat in a race than that which they have already qualified for The Technical Inspector must make the determination You may not run a different boat if you have suffered mechanical damage 7 Check the intake grate for damage and secure mounting 8 Inspect the jet pump for rocks or debris that may have been lodged inside 9 Check the operation of the steering compo nents and adjust or tighten as necessary 01 7 www SeaDooManuals net SECTION 01 GENERAL RACING INFORM
9. 2121 Watts Drive Mims FL 32754 Phone 407 383 4713 Fax 407 383 4713 http www bv net SKAT TRAK PERFORMANCE PRODUCTS Impellers 654 Avenue K P O Box 518 Calimessa CA 92302 Phone 714 795 2505 Fax 714 795 6351 TEAM BUTCH Racing Parts 7357 Expressway Court Suite A Grand Rapids MI 49548 Phone 616 281 7511 Fax 616 281 7515 www teambutch com WATERCRAFT MAGIC Race Parts and Engine Modifications Bill O Neal 2264 East Alosta Glendora CA 91740 Phone 818 914 9509 Fax 818 914 6019 RADAR SALES Radar Guns 5640 International Parkway Minneapolis MN 55428 Phone 612 533 1100 Fax 612 533 1400 www radarsales com 05 7 www SeaDooManuals net n uy Ec TOC Mua i n ir IPLE www SeaDooManuals net
10. Before checking ignition timing with a strobo scopic timing light dynamic test it is mandatory to scribe a timing mark on the PTO flywheel stat ic test corresponding to the specific engine Also the timing mark scribed on the PTO flywheel can be used to troubleshoot a broken magneto woodruff key NOTE Do not use the factory mark found on the PTO flywheel to check ignition timing or trouble shoot any problems W CAUTION The relation between the PTO flywheel mark position and crankshaft position may change as the PTO flywheel is screwed on the crankshaft As an example when the PTO flywheel is reinstalled on the crank shaft it can slightly turn on the crankshaft when the engine is accelerated even if it is properly torqued This is enough to obtain a false ignition timing reading Always verify PTO flywheel mark position before checking ignition timing with an appropriate timing light 787 787X and 947 Engines Normally ignition timing adjustment should not be required After it is set it should remain correctly adjusted since all the parts are fixed and not ad justable The only time the ignition timing might have to be changed would be when replacing the crankshaft the magneto rotor the trigger coil and the MPEM If the ignition timing is found incor rect you should first check for proper crankshaft alignment This might be the indication of a twist ed crankshaft With this DC CDI system the ignition
11. Crankshaft Alignment at Connecting Rod Journal Crankshaft misalignment at connecting rod jour nal may cause the crankshaft to be hard to manu ally turn Verification can be done by measuring deflection at each end of crankshaft Refer to IN SPECTION in this section If deflection is found to be greater than specified tolerance this indicates worn bearing s bent and or misaligned crankshaft For engine disassembly procedure refer to appro priate model year Shop Manual Inspection Visually inspect parts for corrosion damage Inspect crankshaft bearings Check for scoring pitting chipping or other evidence of wear Make sure plastic bearing retainer cage 15 not melted Rotate and make sure bearings turn smoothly If crankshaft and or components are found worn or damaged it must be replaced or repaired by a shop specializing in this type of work The inspection of engine crankshaft should in clude the following measurements NEW PARTS WEAR min max LIMIT 0 05 mm 0 08 mm 002 in 0031 in 0 39 mm 0 737 mm 1 2 mm 015 in 029 in 047 in Connecting Rod Straightness Crankshaft deflection Connecting rod big end axial play Align a steel ruler on edge of small end connect ing rod bore Check if ruler is perfectly aligned with edge of big end 03 46 1 1 Ruler must be aligned with edge of connecting rod here 2 Align ruler here Crankshaft Deflection Cra
12. E 219 000 080 LOL s www SeaDooManuals net SEA DOO RACING HANDBOOK This information relates to the preparation and use of watercraft in competitive events Bombardier Inc disclaims liability for all damages and or injuries resulting from improper use of its contents We strongly recommend that these modifications be carried out and or verified by a highly skilled professional watercraft racing mechanic It is understood that racing or modification of any Bombardier made watercraft may voids the watercraft warranty Racing of any product including watercraft involves an assumption of risk by each competitor In watercraft racing these risks include but are not limited to drowning death broken bones collision with another watercraft and falls onto the watercraft or into the water The danger and risk is multiplied as speed is increased Protective clothing and equipment cannot protect a racer in all conditions All racers should obtain a copy of the model year Shop Manual and necessary tools before attempting any mechanical work Many aspects of watercraft fine tuning blueprinting and modification are critical to insure safe and proper watercraft operation If you are not absolutely sure how to accomplish an adjustment procedure or modification please have an authorized Sea Doo dealer who is involved in racing perform the task some Sea Doo watercraft may have to be altered from their stock
13. ENGINE PREPARATION Install pump with reducer and nipple to the oil supply hose of the rotary valve shaft F01B32A 587 657 AND 717 ENGINES 1 Pump with reducer and nipple F01B34A 787 ENGINE 1 Pump with reducer and nipple Activate pump and pressurize to 5 PSI 34 kPa Check plug of the rotary valve shaft in crankcase Remove PTO side spark plug If pressure drops it indicates a defective PTO side crankshaft inner seal Remove MAG side spark plug If pressure drops it indicates a defective MAG side crankshaft inner seal If the above mentioned components are not leak ing and there is a pressure drop remove the rota ry valve cover Check the seal of the rotary valve shaft If the rotary valve shaft is not leaking it could indi cate a defective engine casting Disassemble en gine and carefully check for defects in castings Pay attention to tapped holes which may go through sealed areas of engine and thus lead to leakage 03 43 www SeaDooManuals net SECTION 03 ENGINE PREPARATION ENGINE LEAKAGE DIAGNOSTIC FLOW CHART PRESSURIZE ENGINE COOLING SYSTEM IS SYSTEM LEAKING NO ES CHECK TESTING KIT REPLACE O RING OF CYLINDER HEAD AND OR CYLINDER BASE GASKET RECHECK ENGINE SEALING PRESSURIZE ENGINE wd IS ENGINE LEAKING Y CHECK TESTING KIT CHECK ALL JOINTED SURFACES SCREW STUD THREADS MOUNTING FLANGES ETC ANY LEAK FOUND YES REPLACE
14. Wait 3 minutes and check if pressure drops if so verify all testing components If kit components are not leaking verify engine jointed surfaces as per following areas spark plugs cylinder head gasket Cylinder base gasket crankcase halves otary valve cover engine plugs exhaust manifold intake manifold except 787 engine oil injection pump except 787 engine Check also small oil injection pump lines and fit tings check for air bubbles or oil column going to ward pump which indicate a defective check valve If the above mentioned components are not leak ing block both oil hoses of the rotary valve shaft using hose pinchers NOTE If leakage stops at this point proceed with Rotary Valve Shaft testing 03 42 If there is still some leakage remove the PTO fly wheel to verify outer seal If no leak is found on the PTO side outer seal re move magneto flywheel and verify crankshaft outer seals Proceed with the Rotary Valve Shaft testing if the crankshaft outer seals are not leaking Rotary Valve Shaft NOTE It is preferable to drain the injection oil from the rotary valve shaft but it is not mandatory Block oil return hose of the rotary valve shaft with a hose pincher F01B31A 587 657 AND 717 ENGINES 1 Oil return hose blocked with a pincher F01B33A 787 ENGINE 1 Oil return hose blocked with a pincher www SeaDooManuals net SECTION 03
15. 3 Retains piston rings which seal the bore Heat flows into piston bosses on normal circular piston center causes distortion to oval left If oval turned right distortion converts to circular shape www SeaDooManuals net FO1D6CA The piston is manufactured out of round the rea son being that wrist pin bosses have a greater vol ume of metal than the other sections of the piston and consequently will absorb more heat The greater the absorption the greater the area will expand Under normal operating tempera tures the piston expands and assumes a more rounded shape Piston Rings Expanding rings are placed in the grooves imme diately below the piston dome They seal the pis ton and cylinder wall Within each ring groove 15 a small pin that provides a locating point for the ring ends his pin prevents the ring from rotating around the ring land Without it rings would catch on the port edges and piston ring breakage would occur When installing a new piston and or piston rings is critically important that piston ring locat Ing pin is matched or indexed with gap in piston ring This should be checked as the cylinders are being installed FO1D6DC 1 Locating pin Two types of compression rings are used with Ro tax pistons 1 rectangular cast iron 2 L type trapezoid molybdenum SECTION 03 ENGINE PREPARATION FO1D6EA RECTANGULAR RING SHOWN ON LEFT SIDE L TYPE RING SHOWN ON RIG
16. 6 Read the burette scale to obtain the quantity of liquid injected in the combustion chamber Record the volume which we will note as NOTE When the combustion chamber is filled to top of spark plug hole it includes an amount of 2 25 cc for this space BR7ES BR8ES have a 19 mm reach head Repeat the procedure for the other cylinder 03 15 www SeaDooManuals net SECTION 03 ENGINE PREPARATION CALCULATING THE COMPRESSION RATIO Uncorrected Compression Ratio The uncorrected compression ratio of an engine is the volume of a cylinder plus the volume of the combustion chamber divided by the volume of the combustion chamber V V5 TM WHERE C R Compression Ratio 1 V 2 Volume of the cylinder Uus B xSxm 4 V Volume of the combustion chamber T 3 1416 B Bore cm S Stroke cm F01D6NA BDC V TDC V2 Stroke EXAMPLE B 76 mm S 64 mm 25006 Co 03 16 76 cm x 6 4 cm x X VQ ME s lt gt 290 3 cc 290 3 cc 27 6 cc at MES C R 11 5 1 UNCORRECTED Uncorrected Compression Ratio of Production Engines e 11 5 1 engine type 587 e 12 2 1 engine type 657 e 12 25 1 engine type 717 e 11 25 1 engine type 787 e 11 75 1 engine type 947 Corrected Compression Ratio In a 2 cycle engine a portion of the stroke is opened to the atmosphere via the exhaust port The corrected compression ratio is calculated as the pis
17. ENGINE PREPARATION F01D3OA SAME AMOUNT REMOVED FROM COVER SEATING SURFACE AND O RING GROOVE BASE 1 Cover seating surface 2 O ring groove depth must be 1 0 0 03 mm 039 001 in Reverify the clearance At assembly the rotary valve timing must remain as per original setting NOTE If rotary valve crankcase surface is worn it is possible to have it reworked at the factory Contact your dealer or distributor Crankshaft and Rotary Valve Shaft Drive Gears Backlash Remove PTO flywheel guard Remove spark plugs rotary valve cover and valve Manually feel backlash at one position then turn crankshaft about 1 8 turn and recheck Continue this way to complete one revolution Backlash must be even at all positions Other wise disassemble engine to find which part is faulty drive gears or rotary valve shaft with exces sive deflection 03 24 ROTARY VALVE TIMING The following tools are required to measure rotary valve opening and closing angles in relation with magneto side piston 295 000 007 295 000 143 FOOBODA For the following instructions lets use these specifications as example OPENING 147 BTDC CLOSING 65 ATDC Proceed as follows Turning crankshaft bring MAG side piston to Top Dead Center using a TDC gauge F01D2lA 1 Bring piston to TDC www SeaDooManuals net For opening mark first align 360 line of degree wheel with BOTTOM of MAG side inlet port Then f
18. The fitting must have at least a 3 millimeter orifice through it and be threaded to accept a Mikuni main jet The fitting must also accept a 1 4 in inside diameter hose 03 51 www SeaDooManuals net SECTION 03 ENGINE PREPARATION 01 235 1 Original fitting threaded to accept Mikuni main jet size 150 2 New 1 4 in T fitting 3 New fitting threaded to accept a Mikuni jet size 200 IMPORTANT It is necessary to readjust the exhaust hard jetting for maximum performance when racing in different water temperatures Because of this it is recommended that you keep a record of the Jet sizes chosen at given water temperatures 03 52 www SeaDooManuals net FUNCTION OF THE COOLING SYSTEM All Sea Doo watercraft are equipped with a total loss cooling system The water supply is taken from a pressurized area in the jet pump between the impeller and venturi The water passes through a tee where a small amount is diverted into the exhaust stream refer to WATER INJECT ED EXHAUST SYSTEM in this section and the majority continues into the exhaust system cool ing jacket to be warmed before entering the en gine On the 1988 91 engines water enters at the bottom of the exhaust manifold and tuned pipe cooling jackets then to the engine On the 1992 97 engines excluding the 717 and 787 engines the water enters the cooling jacket on the tuned pipe and travels into the cooling Jacket around the exhaust manifold after which it
19. Used to start the race when the rubber band start is not used or signifies that the Green Flag ab course 15 clear and the race is in progress Warns the rider of a hazard on the course After the yellow flag is displayed riders Yellow Flag con tinue with caution and be aware of hazards You may continue to race in a responsible manner signifies the event will stop regardless of positions of machines on the Rude course The red flag will be used if the race course has become hazardous or the 9 start is jumped by one or more riders Riders must return to the starting line with caution When a rider is signaled with a black flag they must leave the race course Black Flag immediately and report to the Race Director This does not necessarily mean that an additional penalty will be given but failure to obey the black flag may result in additional penalties Signals that a rider is being overtaken and lapped by another rider Competitors must make way for overtaking racers to pass safely Riders not yielding may be penalized Blue Flag with Diagonal Yellow Stripe Crossed Checkered and White Flags signifies the halfway point of the race White Flag signifies the riders have started the last lap oignifies the completion of the race As a rider passes the checkered flag they Checker Flag have completed the last lap of the race regardless of the number of laps they have completed www SeaDooManuals net S
20. adjust the desired fuel flow with the screw closed by changing the size of the jet alone In this way if the screw was used later the fuel mix ture could not get lean enough to cause an engine seizure Trace to the needle valve and notice the relation ship between the spring and the needle The spring exerts pressure through the arm onto the needle The size of the fuel passage hole in the valve seat contributes to the performance of the carb in a couple of different ways First and most important the hole size helps determine pop off pressure Four things combine to create pop off 1 Suction within the carb manifold pressure 2 Atmospheric pressure 3 Arm spring pressure 4 Fuel pressure acting on the needle valve Hydraulic principles apply in this instance There is fuel pressure acting against the exposed end of the needle valve with this pressure being mea sured in PSI For example with a 2 0 size needle valve the fuel pressure pushes against the nee dle through the opening with a certain force you increase the needle valve size to 2 5 and re tain the same arm spring the fuel has a larger sur face to push against and can move the needle more easily So increasing needle valve size ef fectively decreases pop off conversely decreas ing the size of the needle valve will increase pop off The arm spring 15 also an adjustable component There are currently 4 springs available with differ ent gram ratin
21. at BDC therefore producing a simultaneous tion and transfer oince there is both transfer and ignition occurring center seals isolate the primary compression ar eas of the crankcase and thereby retains the equi librium of crankcase and cylinder areas Transfer Ports To achieve greater efficiency Rotax engineers have designed the engines with 2 extra transfer ports An engine with 4 transfer ports enhances the rap id escape of the air fuel mixture from the crank case into the combustion chamber SECTION 03 ENGINE PREPARATION FO1D6KA 1 Transfer ports 2 Intake port The configuration of the transfer ports is termed as being tangential type flow In other words the indirect positioning of the transfer port open ings in the cylinder creates an upward swirling movement of the air fuel mixture This swirling action is in general limited to the sides of the cyl inder wall FO1D6LA Flushing action of transter flow the fresh mixture staying close to the walls of the cylinder expels the burnt gases without mixing with them and or causing turbulence When this upward swirl reaches the cylinder head dome it attempts a downward inward move ment However since the piston Is also ascending at the same time a vortex type of effect occurs This vortex retains the air fuel mixture in the up per part of the combustion area therefore burnt exhaust gases are completely expelled b
22. 1 Determine that the carburetion is not adjusted too lean 2 Iry a higher octane fuel 3 Retard ignition timing to remedy the problem 4 Determine that the exhaust system Is providing for adequate flow Ignition Timing Specifications Refer to appropriate model year Shop Manual Ignition Timing Procedure 587 657 657X 717D and 717 Engines It is very important that timing specification is checked at 6000 RPM with a cold engine When preparing an engine for racing the flywheel should be checked for the correct phasing be tween the firing points of the MAG and PTO spark plugs The firing points should be exactly 180 apart if there is any deviation between the firing points the flywheel should be changed for a per fect unit to obtain maximum performance In order to check the flywheel for proper phasing the crankshaft itself must first be checked for the 180 phasing refer to crankshaft cautions and in spection Use the procedure for verifying PTO fly wheel timing mark position and repeat the procedure that was done to the MAG side oylin der on the PTO cylinder There should be 2 marks on the PTO flywheel 180 apart The ignition fires every 180 of crankshaft rotation at TDC and BDC so the marks should line up exactly when viewed with a timing light If they do not line up exactly and the crankshaft is correctly phased the flywheel magnets may not be phased exactly 180 apart SECTION 03 ENGINE PREPARATION
23. 947 engines equipped with a balancer shaft to prevent this occurrence 03 79 www SeaDooManuals net SECTION 03 ENGINE PREPARATION 10 Synchronize the carburetors and set the idle according to the appropriate model year Shop Manual then synchronize the oil pump arm At wide open throttle the fuel oil ratio deliv ered by the oil pump is 40 1 If additional oil is desired pre mix a quantity of oil with the fuel to achieve the desired fuel oil ratio 11 Ensure that carburetor calibration is correct Refer to carburetor tuning in this section as a tuning guide and reference for available jets 12 Break in your freshly built engine All the me ticulous work that you have done could be for little or no gain if the engine is not properly broken in Follow the directions for engine break procedure as outlined in this section and your engine will deliver more power longer USING A RADAR GUN FOR TUNING Using a radar gun 15 an accurate way to determine the performance of a race craft If you plan to pur chase a radar gun for testing be sure to buy one that is designed for testing watercraft These ra dar guns have a digital marine filter that elimi nates problems caused by waves and ripples in the water It is also important to purchase a gun that measures the rate of acceleration Proper use of a radar gun is necessary to get ac curate and consistent readings One of the most common mistakes that is made
24. GASKET OR O RING RE SEAL LEAKING AREA CHECK SMALL OIL LINES OF INJECTION PUMP AIR BUBBLES FOUND YES OR OIL MOVING REPLACE CHECK VALVE S LINE S TOWARD PUMP BLOCK LARGE HOSES OF ROTARY VALVE GEAR LUBRICATION SYSTEM NO IS ENGINE STILL LEAKING CHECK TESTING KIT CHECK CRANKSHAFT OUTER SEAL OF PTO AND MAG SIDES YE PRESSURIZE ROTARY VALVE GEAR ARE SEALS LEAKING REPLACE DEFECTIVE SEAL S RESERVOIR IN CRANKCASE NO PRESSURIZE ROTARY VALVE GEAR RESERVOIR IN CRANKCASE YES IS RESERVOIR LEAKING RECHECK ENGINE SEALING UNSEAL PTO CYLINDER AND MAG CYLINDER SEPARATELY BY REMOVING THE APPROPRIATE SPARK PLUG IS RESERVOIR LEAKING CHECK FOR LEAKAGE AT ROTARY CHECK TESTING KIT VALVE SHAFT CRANKCASE PLUG REPLACE OIL SEAL OF ROTARY ANY LEAK FOUND VALVE SHAFT END OR REPLACE CAP REPLACE DEFECTIVE SEAL S YES IS RESERVOIR LEAKING REMOVE ROTARY VALVE COVER CHECK NO SEAL OF ROTARY VALVE SHAFT IS SEAL LEAKING CAREFULLY INSPECT ENGINE CASTINGS PARTICULARLY THE THREADED HOLE AREAS ANY LEAK FOUND REPLACE DEFECTIVE PARTS 7 ENGINE IS PERFECTLY SEALED INTERNALLY REPLACE DEFECTIVE SEAL F00D07S 03 44 www SeaDooManuals net CRANKSHAFT INSPECTION Crankshaft Misalignment and Deflection oince it is an assembled crankshaft it can be come misaligned or deflected Crankshaft can be twisted on center main journal changing timing of one cylinder in rel
25. The cycle is complete in one revolution on a 2 stroke engine TDC Top Dead Center The position of the piston when it reaches the upper limit of its travel inside the cylinder BTDC Before Top Dead Center ATDC After Top Dead Center BDC Bottom Dead Center The position of the piston when it reaches the lower limit of its travel inside the cylinder BBDC Before Bottom Dead Center ABDC After Bottom Dead Center Bore Diameter of the cylinder Stroke The maximum movement of the piston from BDC to TDC It is characterized by 180 of crankshaft rotation Combustion Chamber Space between cylinder head and piston dome at TDC Displacement The volume of the cylinder displaced by the piston as it travels from TDC to BDC The formula is 2 Bore x Stroke xm Volume expressed in cc 4 cc cubic centimeters m 3 1416 NOTE To transfer cc to cubic inches divide cc by 16 387 Compression Reduction in volume or squeezing of a gas Theoretical Compression Ratio Combustion Chamber Cylinder Volume Volume Combustion Chamber Volume _ Theoretical Compression Ratio Corrected Compression Ratio Combustion Chamber Cylinder Volume Corrected Compression Ratio Volume Combustion Chamber Volume Cylinder volume with the piston just closing the exhaust port www SeaDooManuals net SECTION 03 ENGINE PREPARATION BASIC ENGINE COMPONENTS FO1D5DS Rings 9 Wrist pin 2 Cylinder 1
26. a good starting point Pro riders experiment with sponson design and location many times before they choose a position or design which is best suited for their riding style Experimenting with location of sponsons Is time consuming but necessary Sponsons that are an gled with the front too far down will cause the rear of the watercraft to drag in the water Spon sons angled with the front too far up will cause the nose of the watercraft to plow You must find the position that works best for you The one sponson position that keeps the pump in the wa ter in corners without sliding out while not creat ing excessive down force oponsons when attached must not exceed the width or length of the bond flange The bond flange is considered the fiberglass joint under the rubber bumper not the bumper Most add on long sponsons will require sanding on the base before attachment to prevent this from occurring www SeaDooManuals net Hole Location in Hull Short Sponsons The vertical measurement must start from under the top edge of the hull This will avoid mounting the sponson too low FO1LBWA 1 Template on hull A 100 mm 3 15 16 in from hull flat surface B 89 mm 3 1 2 in from hull flat surface C 115 mm 4 1 7 32 in from center of radius Be sure to verify stud location on your particular sponsons and compare to dimensions on dia gram Some minor adjustments may be neces sary Mark center of holes in gelcoat
27. and catalyzed CONCEPT DCU 2020 Clear DELTA PAINTING PROCEDURE With Low VOC Mainly in California For additional information refer to PPG P Bulletin no 157 Surface Preparation Primer DELTA M PRIME PPU 166 DELTA 2800 Color How to Mix Mix DELTA M 2800 2 1 2 parts colors to 1 DU 6 Catalyst Application Apply 2 coats of DELTA M Polyurethane Color Apply the first coat at 1 5 1 8 wet mils Allow a minimum of 15 minutes flash time prior to application of the second coat Apply a second coat of DELTA using the same technique as the first application paying strict attention to gun set up and proper equipment choices Recommended Spray Equipment Gun Manufacturer DeVilbiss HVLP Can Am F J dT osie F 63D 02N HT no 9072 p 1 4 mm 055 in 1 5 mm 059 in 1 2 mm 047 in 2 5mm 098 in Air Cap 797 264 63PW 02 03 C9062 Sip ence 26 30 cm 26 30 cm 26 30 cm 26 30 cm 10 12 in 10 12 In 10 12 in 10 12 in Pin a 227 340 mL mn 227 340 mL mn 227 340 mL mn 227 340 mL mn y 8 12 oz mn 8 12 oz mn 8 12 oz mn 8 12 oz mn Air Pressure 42 51 kPa 42 51 kPa 42 51 kPa 62 kPa At the Gun 60 75 PSI 60 75 PSI 60 75 PSI 9 PSI Dry Time at 21 C 70 F Force Dry dust free 25 35 minutes Allow 20 minutes purge time at 27 32 C 80 90 F tack free 2 1 2 3 hours before bake Bake 75 minutes at 65 C 150 F or 40 minutes at 82 C 180 F Allow to cool after tape sand Overnight fo
28. area This area is basically a ledge projecting beyond combustion chamber area In operation as the piston ascends and approaches the ledge a rapid squeezing action is applied to the air fuel mixture contained in the area immediately between the piston dome and the ledge This squishing action forces the entrapped mixture rapidly into the com bustion chamber area creating a greater mixture turbulence Additionally the small volume and large surface area of the squish band allow a bet ter cooling of the end gases to help prevent deto nation 03 13 www SeaDooManuals net SECTION 03 ENGINE PREPARATION F01D64A 1 Solder 2 Measure here W CAUTION Do not use acid core solder the acid can damage the piston and cylinder NOTE If you are machining your cylinder head to Increase compression ratio be sure to respect proper squish band tolerances in the machining process Squish Area of Production Engines e 1 30 mm 1 70 mm 051 in 067 in engine type 587 e 1 00 mm 1 40 mm 039 in 055 in engine type 657 e 1 30 mm 1 70 mm 051 in 067 in engine type 1 e 1 30 mm 1 70 mm 051 in 067 in engine type 87 03 14 Squish Area of Prepared Engines Uncorrected compression ratio up to 14 5 1 e 1 00 mm 1 60 mm 039 in 063 in engine type 587 e 0 80 mm 1 40 mm 031 in 055 in engine type 657 e 1 00 mm 1 60 mm 039 in 063 in engine type
29. at the decision If your complaint concerns the legality of a given watercraft s modification go to the Technical In spector The Inspector knows the modification rules better than any other official it s their job If you believe that a boat is illegal tell the Inspector If the item can be visually inspected without any tear down the Inspector will normally keep an eye open for the infraction If the infraction re quires engine or pump tear down it would then be your responsibility to lodge a formal protest The protest must be in writing to the Race Direc tor The protest must be specific not general in scope For example you may protest the fuel in duction system ignition system or crankshaft but you could not protest the entire engine as a whole unit Each item protested must be accom panied with a protest and an additional fee to cov er tear down The fee is determined by the Technical Director and Race Director You are al lowed only a short time period to file the protest after the race concludes Check your rule book for specific details Remember officials can make mistakes but so can racers When problems arise conduct yourself in a pro fessional manner Attempt to locate and deal with the official that handles that aspect of the race If you don t get satisfaction then it s time to take your problem to the Race Director The outcome may not always be to your liking but if you handle yourself professio
30. bar 10 The fuel cap must fit tightly 11 The throttle lever must work freely and spring back to the idle position 12 The safety lanyard will be checked for proper operation 13 he engine idle will be checked to determine that the engine will not idle in the event of lan yard failure 01 6 14 Inside the hull the fuel tank oil tank and bat tery box will be checked for secure mounting 15 All fuel lines must be secured to the carbure tor and fuel tank with clamps or zip ties Fuel injected engines must have approved high pressure fuel lines There can be no fuel leaks of any type 16 Flame arresters must be USCG approved and not modified 17 Electrical components must be properly wired insulated and routed away from high temperature components 18 Decals that are required to be placed on the boat by the sanctioning body promoter or sponsor will also be checked 19 You will be required to show your USCG ap proved flotation device and approved full face helmet without face shields at this time 20 he sponsons must not protrude beyond the width of the hull bond flange with the molding removed see appendix in rule book If it is such the case on your watercraft it is neces sary that the sponsons be filed or ground down to fit within the bond flange in order to be race legal NOTE The inspector will place a small decal on your boat upon satisfactory completion of the in spection If you a
31. but other sponsors will recognize your work and may throw support your way Keep your pit area clean bring a small waste can for your pit its another place to put decals it adds to the professional look You are required to have a fire extinguisher in your pit Do not set It on the ground it will be hard to locate in the event of an emergency Attach a hanger to one tent post and place the extinguisher on it Your fuel contain er should be of high quality red in color a require ment not normally enforced by the promoter and stored away from smoking areas There should be no horse play in your pit area again your conduct and that of others with you is a direct reflection on your professionalism Do not loose your temper act like a child or allow yourself and those with you to use profane lan guage under any circumstance INTERACTION WITH RACE OFFICIALS There are many officials that you will come in con tact with during race day These officials have spe cific duties required of them all of which play a part in how efficiently the race is conducted Al ways treat the officials with respect Never raise your voice use profane language or make rude gestures to officials You can always discuss your differences without loosing your cool Being loud and obnoxious will not change the officials mind on a decision but it can sway his opinion on future matters normally against you Treat all officials courteously it
32. clockwise to advance SECTION 03 ENGINE PREPARATION A25E0RA TYPICAL 1 To retard 2 To advance To adjust loosen 3 armature plate retaining screws and slightly rotate armature plate In prop er direction NOTE As a guideline turn the armature plate the same amount needed to align mark on PTO fly wheel A25E0VA TYPICAL 1 Retaining screw Example 1 When PTO flywheel mark is on right side of timing tool slot it indicates advanced timing 03 63 www SeaDooManuals net SECTION 03 ENGINE PREPARATION F01H5UA 1 Too advanced timing In this case turn armature plate clockwise when facing it Example 2 When PTO flywheel mark is on left side of timing tool slot it indicates retarded timing FO1H5VA 1 Retarded timing In this case turn armature plate counterclockwise when facing it After adjustment tighten armature plate retaining screws W CAUTION Armature plate screws must have Loctite 242 blue applied before tightening Make sure armature plate screws are well secured Reinstall removed parts 03 64 Recheck ignition timing make sure engine Is cold Repeat armature plate positioning procedure if timing mark position is not adequate 787 787X and 947 Engines To correct the ignition timing the data of the MPEM is changed using the MPEM programmer Through the MPEM programmer the ignition tim ing can be advanced up to 3 or retarded up to 4
33. configuration even in the stock class in order to meet racing requirements established by the race sanctioning body It is important to refer to the racing rule book for direction When racing do so within the confines of the official race meet Do not disturb other boaters or others using the waterway KEEP YOUR SEA DOO RACE LEGAL www SeaDooManuals net INTRODUCTION INTRODUCTION Welcome to the world of SEA DOO watercraft racing The information in this manual contains the theory and operating principals of the SEA DOO watercraft systems It provides the foundation needed for set ting up the watercraft for racing purposes All racers should obtain a copy of the model year Shop Manual and necessary tools before attempting any mechanical work Many aspects of watercraft fine tuning and blueprinting which are contained in this handbook are critical to insure safe and proper watercraft operation If you are not absolutely sure how to accomplish an adjustment or procedure outlined in your service manual please have your local authorized SEA DOO dealer perform the task The handbook also provides information on race day activities rider presentation general racing practic es sponsor solicitation and other useful tips to successful racing some sea doo watercraft may need to be altered from their stock configuration even in the stock class in order to meet racing guidelines established by race sanctioning bodies It is important
34. do for the sponsor the more sup port you can count on in the future Types of services can include 1 Placing the product name on various racing equipment such as your boat truck trailer hel met wet suit or tent Different decal size or lo cation can be dependent upon the amount of support received by the sponsor 2 News releases can be sent out to the maga zines and newspapers detailing your wins and sponsor support 3 You can provide your sponsor with your trophy to be displayed in their place of business or of fice 4 You can make personal appearances at their business or fund raisers to sign autographs or to talk about the effectiveness of their prod ucts Your proposal must include a list of the races you will compete in for that season The listing of rac es should include the date of each event and de tail the estimated rider and spectator turnout Racers competing on the National Tour that are ranked in the top five in the world in their respec tive classes seek an entirely different level of support than most racers These racers normally receive support from the manufacturer of the wa tercraft they race Some riders receive support di rectly from manufacturers race team directors while others receive support from the manufac turer through factory race centers These individ uals have achieved the highest goals in racing through hard work and commitment to their rac Ing program They started
35. if modifications are made to the en engine There are specific set of rules for racing know what those rules are If your engine is operating at higher than stock RPM the rev limiter must be changed ingly Never operate the engine without a rev limiter oloppy engine building will usually result in less power output and possible breakdowns Follow the assembly and disassembly proce dures outlined in the appropriate model year Shop Manual MODEL YEAR SHOP MANUAL 1989 1990 1991 1992 1993 1994 1595 1996 1997 1998 PART NUMBER 295 000 060 219 100 002 219 100 004 219 100 006 219 100 008 219 100 010 219 100 013 219 100 031 219 100 048 219 100 068 Always use a laboratory blended fuel Do not add your own octane booster Doing so will re sult in unknown burning rates of the fuel Se lect a fuel with a given octane rating and tune your engine to maximum efficiency for that fu el REFER TO OCTANE REQUIREMENTS FOR ROTAX ENGINES Correct your carburetor jetting to compensate for engine modifications Reconfirm correct jet ting at the race site Atmospheric conditions ALTITUDE TEMPERATURE BAROMETRIC PRESSURE and HUMIDITY may be quite dif ferent at the race site or during different times of the year 03 2 gine BASIC ENGINE TERMINOLOGY Cycle In a combustion engine a cycle is accomplished when the 4 phases intake compression combustion and exhaust are complete
36. in this manner as the throttle opens each circuit in turn contributes to the total fuel requirements of the engine Transition Circuit Transition circuit controls the fuel flow for a smooth transition to the high speed circuit If the transition circuit is far enough out of adjust ment it may become difficult to get to the high speed circuit and the engine will not rev up SECTION 03 ENGINE PREPARATION High Speed Circuit High speed circuit controls the fuel flow in addi tion to the low speed and transition circuits The high speed screw can control up to as much as 1 2 of the fuel delivered by the high speed circuit de pending on the relative size of the high speed jet This adjustability allows for a wide range of tuning without changing an internal jet Jetting The oxygen content of air varies with different at mospheric conditions Cool dry air at a high baro metric pressure has more oxygen molecules per cubic foot than does hot moist air at low baromet ric pressure readings Hot air expands therefore there are less oxygen molecules per cubit foot At low barometric pressure also allows air to expand An increase in altitude results in a decrease in barometric pressure Air with high humidity has more water molecules which take up space so there is less room for oxygen molecules Since oxygen is what is needed to mix fuel to provide a burnable mixture changing atmospheric condi tions will require a change i
37. intake is asymmetrical In piston port engines intake dura tion is symmetrical With the central rotary valve complete control of intake timing means greater torque at lower RPM s more peak power and eas ler starting some modern engines such as the 947 use reed valves in the crankcase to increase overall perfor mance over piston port designs The main advan tages are ntake port directly positioned in the crankcase similar to a rotary valve engine Short intake track substantial improvement of engine torque The reed valve engine has also other benefits worth mentioning lightweight and compact design easier assembly and maintenance cost effective design However reed valve engines do have some disad vantages over the rotary valve engine These dis advantages are he intake port is restricted by the reeds and cage he reeds tend to separate air from fuel Since the crankcase vacuum must first open the reed to permit intake this initial force is not fully applied to the intake operation Conse quently there is a partial loss of intake poten tial At high speeds the delay in closing the reed affects the reopening of the reed Again poten tial volumetric efficiency is affected The continual rebounding of the reed causes further intake restrictions 03 22 Inspection of the Rotary Valve Inspect rotary valve cover for warpage Small de formation
38. is not higher than pro duction However if the compression ratio is high er it may become necessary to use a higher octane fuel or engine damage will result Do not use a compression gauge to determine compres sion ratio A compression pressure test is useful in checking general condition of any engine but is useless when checking compression ratio Minimum octane requirement for production en gines 87 RM regular unleaded R Research octane number 90 M Motor octane number 84 R M 2 Minimum octane requirement for engines with higher compression ratio premium unleaded Up to 14 1 2 108 112 motor octane Over 14 1 114 motor octane RAVE VALVE OPERATION Theory For a 2 stroke cycle engine to have high power capacity at high crankshaft speeds a high volu metric or breathing efficiency is required and the fresh charge losses must be minimized The re sult Is achieved by opening the exhaust port early and utilizing the resonant effects of the tuned ex haust system to control fresh charge losses 87 octane 03 17 www SeaDooManuals net SECTION 03 ENGINE PREPARATION When an engine of this design is run at a high speed efficiency falls off quickly The relatively high exhaust port effectively shortens the useful power stroke and because the exhaust system Is tuned for maximum power there is a large in crease of fresh charge losses at lower speeds As a result the torque decreases along with
39. of the cooling system could result In less power output and engine reliability On the 1988 91 engines the cooling water pro ceeds into the engine via a water distributor into the crankcase then up to the cylinders On the 1992 97 engines the cooling water proceeds from the exhaust manifold cooling Jacket into the cylinder cooling Jacket via the passages below the exhaust ports On all engines the water sur rounds the cylinders and moves upward through calculated holes in the cylinder head exiting the engine at the intake side of the cylinder head 03 53 www SeaDooManuals net SECTION 03 ENGINE PREPARATION 1403103 9uoz aJnssaJg 9SOU peddois si i RN JO JUIOd 19907 1918 A 11001 1opnno pue 9siou 10J 526 sneuxo 19 9 9 Jeau gt pee q Jo SAAO J JO S E ou ig di 1 10615 sjo oef peau pue edid paun 5 Ysa 9SOU ajea eulDU3 4 012 902 Buipee q 0966 96 Speeoxe Duipee q
40. out remain the same While the venturi section of the pump Is not technically impressive or complicated in ap pearance its simple shape and diameter are very crucial to pump performance A small increase of the venturi outlet diameter will reduce watercraft top speed but improve acceleration at lower speeds Conversely a small decrease in venturi outlet diameter will reduce low speed accelera tion but improve top speed After exiting the ven turi the water passes through a steering nozzle where it can be directed right or left to turn the watercraft Understanding the basic function of a jet pump should make it easy to realize that steer ing control is only accomplished under thrust oteering control at lower speeds or idle is mini mized Always keep in mind that as the throttle lever is released less directional control will be available To control or steer the watercraft throttle must be applied PROPULSION SYSTEM ANALYSIS FO1J40A 1 Water inlet 2 Axial flow jet pump 3 Venturi 4 Nozzle 04 2 Water Inlet The function of the inlet is to carry the water to the jet pump with minimum loss Another very im portant function is to assist the jet pump in trans forming water volume into thrust F01J4RA 1 Ride shoe and hull sealed and blended 2 Sealed and blended 3 Water flow inside of the inlet 4 Sealed and blended intake grate The intake grate must be properly installed and blend in with t
41. piston available It is 0 25 mm 010 in larger in diameter than the stock piston When the oversize is installed the guillotine will have a minimum clearance of 0 375 mm 015 in with the cylinder bore This 15 the minimum operating clearance the guillotine should be used with Clearance less than 0 375 mm 015 in will require reworking of the guillo tine to achieve the proper clearance and radius NOTE When boring the cylinders on the 787 en gine the displacement will be 785 76 cm after boring and honing The engine will no longer be race legal for the 785 cc class racing In order to maintain legality new cylinder sleeves and new stock diameter pistons should be installed FUNCTION OF THE ROTARY VALVE INTAKE SYSTEM Controlling the opening and closing of the intake port is also a critical factor in the volumetric effi clency of an engine Best V E s are obtained by asymmetrical intake timing opening and closing of intake port operates independently with regard to piston position Example 130 BTDC opening 65 ATDC closing While also allowing for an un obstructed intake tract to provide maximum air flow into the engine This is best accomplished by using a rotary valve type inlet 03 19 www SeaDooManuals net SECTION 03 ENGINE PREPARATION The rotary valve engine is one of the most innova tive concepts to be applied to 2 stroke watercraft engines oimply stated the design produces more horse power ou
42. race then you will be placed in the LCO Last Chance Qualifier race In the only the top 1 or 2 riders will transfer Know what the cut off point is for transfer positions and what race num ber the is In some cases heat races will not be necessary due to a low rider turnout for your class In the event that this is the case you will normally run 2 races called motos You will be scored on each race and the combined totals will be your overall score Details on points awarded and calculation of points to determine the overall winner are detailed in the rule book After your race the official results for your race will be post ed within 15 minutes If there is a mistake see the Chief Scorer or Race Director at this time 9 Staging for the Race When you come to the line for your race you will be lined up on the starting line This is called stag ing You will be lined up in 1 of 3 ways 1 You will draw for your position 2 The computer will line you up randomly as post ed on the pit board 3 You will be lined up in order of your finish posi tion from your previous qualifier or heat race 10 Starting Once in position on the line you will be allowed 1 or 2 holders to keep your boat in position safely The holders will hold back your boat while the en gine is running just before the rubber band is snapped lt is important that you practice your starts with your holders Holders need to learn how to hold
43. sjueuoduJoo 1sneux 000 Sm p jq edid peun peddois si JO JUIOd 19907 pue uononpoJ 9siou 40 526 sneuxo 9 oAo u19 s 1 JO SAA0 sjo oef JO 5 euus JS pue edid u19 s S peuni SMO J J910AA 9SOU 8509 401 905 JOJEM 1911000 uni O 2266 96 Duipea q u d q edid peuni soejeAnoe 10sues JO juiod 5 INALSAS 3NIDN 414 03 56 www SeaDooManuals net SECTION 03 ENGINE PREPARATION 787 ENGINE COOLING SYSTEM Temperature a sensor Uppermost point of Water regulated cylinder monitoring circuit tuned pipe head limits beeper when allows bleedin by the water flow water flow temperature regulator valve and injected directly into exhaust gas for noise reduction and performanc Improvement exceeds 96 99 C 205 210 F Cooling System I
44. the area that is blacked out transfer ports as outlined in the chart below k u i cii w S i W 3 3 SSH N ERANS lt 18 hee Wa dn eite Piston at bottom dead center E FS S ws N F00D16A OR PORT STOCK MODIFIED ALL MEASUREMENTS ARE MADE FROM THE OUTER EDGE OF THE PISTON AT BOTTOM DEAD CENTER Modified MODIFIED IT IS VERY IMPORTANT TO MAKE BOTH IN TAKE PORTS SYMMETRICAL AND THE SAME VOLUME TO INSURE EQUAL INTAKE VELOCITY AND VOLUME TO BOTH CYLINDERS 03 37 www SeaDooManuals net SECTION 03 ENGINE PREPARATION Exhaust System Modification F00D18A Modify the exhaust system as shown in the illus tration This modification may be used in lieu of an aftermarket system and yields an increase in per formance 03 38 www SeaDooManuals net ENGINE LEAKAGE TEST All Engines Except 947 General A Sea Doo Engine Leak Test Kit P N 295 500 352 is available to help diagnose engine problems such as engine seizure poor performance oll leakage etc Before disassembling any components of the en gine it is important to perform a leakage test to determine which part is defective It is also very important after servicing the engine even for a complete engine rebuilt to perform an other leakage test at this stage it may avoid fur ther engine problems and minimizing the risk of having to rem
45. the other cylinder 2 Intake port covered As the piston descends the intake port is blocked by the rotary valve and pressure begins to build inside the crankcase primary compression The exhaust port is uncovered as the piston continues Its course downward and burnt gases are al lowed to escape www SeaDooManuals net Transfer F01D6WA 1 Fresh charge for the other cylinder 2 Fresh charge 3 Intake port covered Near the bottom of the downward stroke the transfer ports are uncovered by the piston and the compressed air fuel mixture in the crankcase rushes into the combustion chamber via the transfer ports Piston dome and combustion chamber configuration and exhaust back pres sures prevent fresh charge air fuel mixture from escaping through the exhaust port his also as sists in clearing the combustion chamber of all burnt gases Rotary Valve Drive Gears Located in crankcase halves between the 2 cylin der bases These gears transmit crankshaft rota tion to the 90 angled rotary valve shaft The helical gear mounted on the rotary valve shaft uses the crankshaft as a power source To prevent overheating and provide lubrication the gears op erate in an oil bath To prevent pressurization of the system a vent tube from the top of the gear chamber returns to the oil reservoir which is vented to the atmo sphere SECTION 03 ENGINE PREPARATION D F01D6XA 1 Pinion on rotary valve shaft 2 R
46. the pit area between races This will allow you to service the boat with easy access to your tools In some cases this 15 not possible be cause the race site will not allow for it 3 Set up where other racers do not have to go through your pit to get to their boat or the wa ter Your pit area is a reflection on your sponsors as well as yourself You should invest in a tent for your pit as soon as you can afford one Always anchor your tent and do not leave it up over night unless it is very secure The tent should be attrac tive and of a light color to be cooler A section of indoor outdoor carpet to set your watercraft stand and tool box on can help add a professional ap pearance www SeaDooManuals net SECTION 01 GENERAL RACING INFORMATION Many racers hang banners of sponsors on their tents to advertise their sponsors This can add ap peal to your area assuming you don t clutter the tent with too many banners Some racers have designed a small billboard and placed it next to their tent The sponsors names have been placed on the billboard with custom paint or decals The billboard can also be arranged to prevent easy ac cess to or through your pit 5ome sponsors may be providing you with very generous support You might want to design something special for them oponsors are always looking for new and innova tive ways to advertise if you can provide that something different it will not only help you keep a sponsor
47. to refer to the racing rule book for direction When racing do so within the confines of the official race meet Do not disturb other boaters or others using the waterway KEEP YOUR SEA DOO WATERCRAFT LEGAL Good luck and success in your race Bombardier Inc www SeaDooManuals net TABLE OF CONTENTS TABLE OF CONTENTS INTRODUCTION em SAFETY eee T VI RACE SANCTIONING ASSOCIATIONS ws castae tesa U VI SECTION 01 GENERAL RACING INFORMATION PREPARING FOR RACE Ss exin _ _ __ ____ 01 2 PREPARING FOR A SAFETY INSPECTION 01 5 PRERACEMAINTENANCE 01 6 MAINTENANCE BETWEEN 01 7 EQUIPMENT AND SPARE PARTS BRING TO THE 01 8 uiii Me INGE IN m ER 01 8 INTERACTION WITH RACE OFFICIALS uuu save qp Ende IUNII 01 9 SPONSORSHIP AND SOLICITATION U 01 10 THE PROFESSIONALS POINT OF VIE VV Esser 01 11 SECTION 02 HULL PREPARATION PREPARING THE HULL FOR INSPECTION 02 2 MEASURING MEME On PA MENSEM fc 02 2 THE FOLE __ 02 2 i T
48. with an awl or center punch When drilling holes in fiberglass start slowly with a light pressure on drill motor as it is easy to drift off your locating point Urethane Foam Cutting Cutting of the urethane foam can be accom plished by using a 35 mm 1 1 2 in hole saw NOTE The center drill bit must be removed from the hole saw Insert a pilot wire through the urethane foam Then insert a 6 mm 1 4 in steel rod through the urethane foam by hand From inside bilge attach the hole saw to the steel rod Refer to the following illustration SECTION 02 HULL PREPARATION F01L61A 1 Urethane foam otart cutting the urethane foam by carefully pull ing hole saw into the foam and operating the drill In reverse position NOTE Depending on hole saw depth approxi mately 3 passes will be required to cut the ure thane foam Keep the first foam core It will be reinstall once the Job is completed W CAUTION When cutting the last portion of urethane foam carefully listen to the sound of the hole saw making contact with the side of the hull Stop sawing immediately and remove the remaining foam by hand Sponson Installation Place a generous bead of 732 multi purpose seal ant P N 293 800 006 along mating surface of sponson and around studs This will help keep wa ter from entering through attachment holes Insert sponson locating studs into corresponding holes inside of hull Install flat washer
49. with radar guns 15 shooting the target from an angle In order to be accurate you must shoot in the line of travel At a 15 degree angle measurements are only off by about three tenths of a percent At 20 degrees it is off by seven percent and at a 45 degree angle it is off by approximately thirty percent It is easier and safer to get an accurate reading when the wa tercraft is heading away from you If it is neces sary to do head in readings try to keep the angle as small as possible 03 80 Many factors cause readings to vary for example sitting on a rocking boat or from moving objects or electrical devises If you expect interference change your position It is difficult to get good readings in choppy water do smooth water test ing when ever possible A spike in the speed can be caused by the rider standing or changing posi tion while the craft is being tested Excessive spray can also confuse a radar gun it is recom mended that you perform your test in the direc tion that creates the least spray from the watercraft The speed of a watercraft does vary at wide open throttle and this will be registered by the radar gun Do repeated runs use the right fil ter and average the results to give you a precise idea of how your craft is performing Keep in mind that acceleration 15 as important or In some cases more important than top speed This depends on the type of race course the wa tercraft will compete on On short course
50. 0 Rotary valve 3 Cylinder head 11 Intake port 4 Cylinder head cover 12 Oil injection pump 5 Spark plug 13 Crankcase 6 Combustion chamber 14 Crankshaft 7 Exhaust port 15 Connecting rod 8 Transfer port 16 Piston 03 3 www SeaDooManuals net SECTION 03 ENGINE PREPARATION Cylinder Head A shaped aluminum alloy casting bolted to the top of cylinder It contains the combustion chamber and is designed with a threaded hole to accom modate a spark plug F01D5AB CYLINDER HEAD SHOWN WITH COVER REMOVED High performance engines use hemispherical heads with squish areas allowing a better disper sion when combustion occurs E I FO1D5FA COMBUSTION CHAMBER SHAPE SHOWN Cylinder Characterized by the presence of intake exhaust and transfer ports It directs the passage of the air fuel mixture from the crankcase to the com bustion chamber A large hole bored through it ac cepts a piston Through the years Rotax engineers have designed many types of cylinder blocks to attain better engine efficiency 03 4 F01D5OA TWO CYLINDERS SHOWN Piston A shaped cast aluminum alloy plug made to fit inside the cylinder bore It is attached to the crank shaft by a connecting rod and wrist pin F01D5RA PISTON SHOWN The piston serves 3 purposes 1 Transmits combustion expansion forces to the crankshaft 2 Acts as a valve for the opening and closing of exhaust and transfer ports
51. 01 SPX 5871 5801 88 01 2810 90 02 5870 94 01 5850 5801 88 01 5872 5801880 5804 91 01 5801 88 01 XP 5854 5855 5801 88 01 _ Body Hull 0862 5801 88 01 1990 Number Bombardier Paint Code Model Name Model Body Hull SP 5803 5801 88 01 1993 Number Bombardier 5810 90 02 Pai GT 5810 5801 88 01 SP 5806 5801 88 01 5810 90 02 5806 93 01 5807 5801 88 01 Model Name Model Body Hull 5806 93 02 1989 Number Bombardier 5808 5801 88 01 Paint Code 0806 93 01 SP 5802 5801 88 01 XP 5852 5801 88 01 5801 88 03 5852 93 01 5813 5801 88 01 Model Name Model Body Hull 5861 5801 88 01 1988 Number Bombardier Paint Code SP 5801 5801 88 01 Model Name Model Body Hull Bd Weed 1992 Number Bombardier Paint Code SP 5805 5801 88 01 5810 90 02 XP 5851 5801 88 01 5804 91 01 5812 58018501 5801 88 01 02 7 www SeaDooManuals net SECTION 02 HULL PREPARATION SEALING OF BODY COMPONENTS Important areas to check hull storage compart ment cover water trap tank drain hoses seat seal and rear baffle Reseal all leaks refer to ap propriate Shop Manual HULL AND BODY MAINTENANCE TIPS To obtain a smooth hull after every use wash wa tercraft with soap and water This will remove res idues which will slow your watercraft Wax the hull periodically When storing outdoors keep your watercraft covered LIGHTWEIGHT PARTS There are several aftermarket manufacturers which produce lighter wei
52. 1 e 1 00 mm 1 60 mm 039 in 063 in engine type 787 W CAUTION Reducing squish area may require using higher octane fuel as well as retarding igni tion timing COMBUSTION CHAMBER VOLUME MEASUREMENT The combustion chamber volume is the region in the cylinder head above the piston at Top Dead Center It is measured with the cylinder head in stalled on the engine I FO1D5VA 1 Combustion chamber NOTE When checking the combustion chamber volume engine must be cold piston must be free of carbon deposit and cylinder head must be lev eled 1 Remove both spark plugs and bring one piston to Top Dead Center a using a TDC gauge www SeaDooManuals net 2 I Wee WN UUUU is NH FO1D2IA 1 Bring piston to TDC 2 Obtain a graduated burette capacity 0 50 cc and fill with an equal part 50 50 of gasoline and injection oll FOOBOBA 1 Graduated burette 0 50 cc 3 Open burette valve to fill its tip Add liquid in burette until level reaches O cc 4 Inject the burette content through the spark plug hole until liquid touches the top of the spark plug hole SECTION 03 ENGINE PREPARATION FOODOHA 1 Top of spark plug hole NOTE The liquid level in cylinder must not de crease after filling If so there is a leak between piston and cylinder The recorded volume would be false 5 Let burette stand upward for about 10 min un til liquid level is stabilized
53. 7 www SeaDooManuals net SECTION 03 ENGINE PREPARATION CYLINDER PORTING MAPS NOTE See tables on next pages for porting map specifications Refer to the following illustration for measurement references F01D7CS 03 28 www SeaDooManuals net SECTION 03 ENGINE PREPARATION Porting Map for Engines Prior to 1995 SERDOOENGINE SPEGICATIONS Main transfer height 54 0 mm Bottom width of main transfers 109 5 mm 113 5 mm Total cylinder height Exhaust outlet height at Y pipe oquish band clearance 1 1 mm Cinder ned volume ose 9250 Combustion chamber volume with 012 8590 Urereedcmwesenm _ TT sm T2 14 Exhaust outlet width at Y pipe 490mm 53 0 mm 03 29 www SeaDooManuals net SECTION 03 ENGINE PREPARATION Porting Map for the 1995 Engines Exhaust port height 36 0 mm 34 2 mm 35 2 mm Exhaust port height bottom to top Rear transfer height bottom to top 1 3 B B 12 481 54 3 mm 54 3 mm 59 9 mm 58 6 mm Bottom width of main transfer 26 5 mm 4 21 9mm 22 3 mm 22 3 mm 24 5 mm 26 5 mm Exhaust outlet width at pipe 490mm 630mm 530mm 530mm 56 0mm Exhaust outlet height at Y pipe 320mm 330mm 330mm 330mm 360mm Combustion chamber volume with Uncorrected compression ratio 11 5 1 12 25 1 12 25 1 12 25 1 11 75 1 omm 8 mm
54. 90242 Phone 310 803 5309 NEPTUNE RACING Carburetors and Exhaust Systems Bo Dupriest 2348 Aqulios Ave S E Palm Bay FL 32909 Phone 407 768 9908 Fax 407 952 7289 OCEAN PRO ENGINEERING Race Parts and Flame Arresters 4119 Avenida De La Palma Oceanside CA 92056 Phone 619 631 5501 Fax 619 631 5504 www SeaDooManuals net ODYSSEY RACING Racing Parts and Engine Modifications R R 2 Courtland Ontario Canada Phone 519 688 6818 Fax 519 688 3099 RACE PAK COMPETITION SYSTEMS Data Acquisition 26806 Vista Terrace Lake Forrest CA 92630 Phone 714 580 6898 Fax 714 580 6897 ROSSIER ENGINEERING Race Parts and Engine Modifications 1340 Okray Avenue Plover WI 54467 Phone 715 341 9919 Fax 715 341 9875 SOLAS U S A INCORPORATED Impellers 5200 NW 165 St Miami FL 33041 Phone 305 625 4389 Fax 305 625 4536 WWW Solas com UMI RACING Steering Components 7442 East Brutherus Road ocottsdale AZ 85260 Phone 602 951 9029 Fax 602 951 3469 www umiracing com WESTCOAST PERFORMANCE PRODUCTS Racing Parts and Carbon Fiber Hulls 3100 East Coronado Street Anahiem CA 92806 Phone 714 630 441 1 Fax 714 630 8874 www teamwpp com SECTION 05 MISCELLANEOUS R amp D RACING PRODUCTS 10504 Norwalk Blvd Santa Fe Springs CA 90670 Phone 562 906 1190 Fax 562 941 5563 RED TOP CARBURETORS TRUE CAD DESIGNS Kevin Groah
55. ATION EQUIPMENT AND SPARE PARTS TO BRING TO THE RACE Racers must be prepared for any situations that may arise on race day However most racers do not have the resources required to attain or to transport all the equipment necessary to cover all possible situations You will have to determine what your capabilities are for the level of racing you are at Pro Expert Novice and just how im portant winning a race is to you serious racers normally have 2 boats of equal ca pabilities If a problem is encountered on one boat before it is qualified for an event the backup boat is used If the boat has already been qualified for a race the parts are taken from the backup boat then used to repair the qualified boat These racers normally bring extra parts as well All racers should be equipped with the Shop Man ual for their watercraft They should have at mini mum the necessary tools to accomplish the service procedures that they are capable of per forming themselves The following is a list of parts and equipment that are recommended for you to have on hand for quick repair when needed 1 Spark plugs A complete gasket and O ring set Iwo sets of piston rings Iwo flywheel keys Extra exhaust couplers A roll of fuel and water line A throttle and steering cable A fuel filter A carburetor rebuild kit A starter motor An ignition coil and Multi Purpose Electronic Module A fully c
56. Alignment shaft P N 295 000 093 or P N 295 000 141 for the HX and XP models HX and XP 5662 Models On these models the PTO flywheel adapter P N 295 000 157 must be used in conjunction with the alignment shaft FOOBO5A 1 Adapter P N 295 000 157 NOTE Ensure the mid bearing is removed to check engine alignment All Models To verity alignment proceed as follows Install housing on hull with 4 nuts Carefully slide shaft through housing SECTION 04 PROPULSION SYSTEM FOOBO6A TYPICAL Insert shaft end into PTO flywheel NOTE Ensure the protective hose and carbon ring is removed to check engine alignment If the alignment is correct the shaft will slide easily without any deflection in PTO flywheel F07D05A TYPICAL 1 Alignment shaft 2 PTO flywheel If the alignment is incorrect loosen engine sup port screws to enable to align PTO flywheel with shaft end NOTE Use shim s P N 270 000 024 or P N 270 000 025 between engine support and rubber mounts to correct alignment 04 11 www SeaDooManuals net SECTION 04 PROPULSION SYSTEM FOODOCA TYPICAL 1 Shim W CAUTION Whenever shims are used to correct align ment never install more than 1 3 mm 0 051 in shim thickness If alignment can not be obtained verify for engine support bending W CAUTION Some models require a shim between hull and pump if shim has been removed at time of pump disassembly b
57. BODY SONEPONEINQqzsssaDU 02 8 HULL AND BODY MAINTENANCE TES ssec orti RIEN E RDUM QU DON IN MK ENDING ES 02 8 LIGATWEIG HT PAR TS u a n 02 8 PONSON KIE secs 02 8 02 1 www SeaDooManuals net SECTION 02 HULL PREPARATION PREPARING THE HULL FOR INSPECTION The production hulls produced by Sea Doo are manufactured to fine tolerances All riders can benefit from truing the hulls Hull truing becomes most beneficial on watercraft equipped with high ly tuned modified engines Exacting tolerances are necessary to attain proper high speed stability The section of the hull where truing is most im portant is trom the rear of the hull to a point ap proximately 1 5 m 60 in forward This is due to the fact that at high speeds only the rear section of the hull is in contact with the water You can not alter the hull configuration more than 2 mm 0 079 in in any direction if you are racing in Lim ited or Superstock Class otherwise your modifi cation will be illegal NOTE The hull bond flange can not be altered in length or width even in the modified classes Do ing so is considered an illegal modification by all sanctioning bodies The following steps must be observed before turning the watercraft upside down remove seat remove battery remove engine and jet pump siphon fuel and oil from tanks NOTE Refer t
58. ECTION 05 MISCELLANEOUS RACER S LOG Event Date Sheet Number Association Hace Director Temperature Barometric Pressure Humidity Water Temperature Mem p gt m JJ O JJ gt TI 5 Intake Grate It is important to keep accurate records regarding the race site and the setup of your watercraft for future reference Doing this will enable you to easily set up your race boat for future events and determine the best tuning for various conditions d www SeaDooManuals net SECTION 05 MISCELLANEOUS AFTERMARKET MANUFACTURERS Aftermarket manufacturers produce products that can be used to replace original equipment parts on your watercraft Some of these parts are designed to simply give the operator a choice of color or styling while others are intended to improve the performance characteristics of the watercraft Sea Doo has encountered many manufacturers of aftermarket parts that have made claims about their product that later could not be validated Some products actually had an adverse affect on performance compare to the production item or caused vehicle damage It must also be noted that Sea Doo can not verify every product claim made by manufacturers due to the constant development of new aftermarket products Sea Doo has found the following aftermarket manufacturers have proven their products to be reliable and of high quality We recommend thes
59. ET MANUFACTURERS 05 6 V www SeaDooManuals net SAFETY AND RACE SANCTIONING ASSOCIATION SAFETY PLEASE READ AND UNDERSTAND ALL WARN INGS AND CAUTIONS IN THIS HANDBOOK This handbook uses the following symbols Identifies an instruction which if not fol lowed could cause serious personal injuries including possibility of death W CAUTION Denotes an instruction which if not fol lowed could severely damage watercraft components NOTE Indicates supplementary information needed to fully complete an instruction Prior to operating the watercraft thoroughly read and understand the Sea Doo Operators Guide and Safety Handbook it will give necessary knowledge required to adequately operate your watercraft Check local and federal boating laws and regula tions in the area where the watercraft is to be used It Is recommended to complete a boating safety course Never operate the watercraft after consuming al cohol and or drugs At race events always respect rules legislated by the organizer and sanctioning association KEEPING YOUR WATERCRAFT LEGAL AND WITHIN THE RULES IS YOUR RESPONSIBILITY VI RACE SANCTIONING ASSOCIATIONS This handbook was written to help in the prepara tion of a Sea Doo watercraft for competitive events Carefully study the association rule book and class of racing you intend to compete in before making any modifications to your water
60. Efficiency The impeller efficiency is related to several pa rameters hydrodynamic blade design ncidence angle turbulence created at the inlet pre rotation of water elative circulation eddy friction cavitation 04 5 www SeaDooManuals net SECTION 04 PROPULSION SYSTEM Impeller Wear Ring Clearance This clearance is critical for jet pump perfor mance Excessive clearance will result in de creased performance Clearance can be checked from water inlet open ing after inlet grate removal or from venturi side after venturi nozzle assembly removal This last method may be more difficult Always remove the safety lanyard from wa tercraft prior verifying the impeller wear ring clearance to avoid any accidental en gine starting Using a long feeler gauge 30 cm 12 In measure clearance between impeller blade tip and wear ring Measure each blade at its center Clearance should not exceed 0 5 mm 020 in If clearance IS greater disassemble jet pump and inspect im peller and wear ring Replace worn parts Refer to appropriate model year Shop Manual F01JOEA TYPICAL MEASURING FROM WATER INLET SIDE 1 Feeler gauge 04 6 FO1JOFA TYPICAL MEASURING FROM VENTURI SIDE 1 Feeler gauge NOTE Remember to stay out of shallow water avoid sand and rocks going through jet pump and damaging wear ring Scratches in wear ring re duce efficiency Impeller Id
61. GK Spark Plugs 18mm 14mm 10 mm 12mm 8 mm 4 12mm x 19 mm Reach Compact Type Projected Insulator Resistor Surface Discharge Inductive Suppressor Type FO2HOMS CROSSCUTS AND GAP STYLES OF SPARK PLUGS SECTION 03 ENGINE PREPARATION WIDE GAP 10 1 0 mm 040 11 1 1 mm 044 13 1 3 mm 050 14 1 4 mm 055 15 1 5 mm 060 20 2 0 mm 080 Firing end construction Special Design Single Ground Special Alloy Dual Ground Special Alloy Racing Type Racing Version of V Type Half Heat Range Standard Center Electrode Fine Wire Center 18 mm 12 mm Electrode 31 64 Booster Gap 14 mm 9 5 mm 3 8 V Grooved Center Electrode wui Standard Type Projected Insulator Type Tap A01E1PS www SeaDooManuals ne Seat Type er Surface Discharge Type V Type 03 67 t SECTION 03 ENGINE PREPARATION MIKUNI BN CARBURETORS REPRINTED WITH THE AUTHORIZATION OF MIKUNI CORP Introduction of the Super BN Carburetor FO1FOWB The Super BN carburetor is the latest in a series of watercraft carburetors from Mikuni The Super BN earns its name because of the increased per formance it delivers over previous model Mikuni BN carburetors What differentiates the Super BN from its prede cessors 1 The fuel pump and jet sections are separated
62. HT SIDE selection of the appropriate type of piston ring is relative to the use of a particular engine For ex ample rectangular rings provide adequate piston sealing for a normal medium revolution engine While performance engines with a higher revolu tion capacity require better than average sealing with L type trapezoid rings Crankcase Crankcases are fabricated as matched halves and are split horizontally They are line bored and must be used as a matched set they can not be mixed with case halves from other matched sets www SeaDooManuals net SECTION 03 ENGINE PREPARATION FO1D5SA 1 Pulse nipple Material is of lightweight alloy to reduce overall engine weight Incorporated into crankcase de signs Is a pulsation nipple a tube connects the pulsation nipple to the carburetor fuel pump to as sist with the fuel pumping cycle The engine crankcase serves 3 main functions 1 Supports the crankshaft in perfect line bore 2 Serves as a primary compression chamber for incoming air fuel mixture 3 Supporting structure for the cylinders arma ture plate coils etc 03 6 Crankshaft F01D1ND CRANKSHAFT SHOWN WITH CONNECTING RODS The engine crankshaft is the backbone of the en gine It converts the reciprocating movement of the piston into rotary movement The crankshaft is supported by ball bearings mounted inside the crankcase lt is finely ma chined to obtain precision journals and perfect align
63. M and its rate of acceleration To open the RAVE valves the MPEM activates a solenoid which directs crankcase pressure to the valves The pressure that is received from the crankcase passes through a check valve allowing only pressure not vacuum to act on the RAVE valve Io close the RAVE valve the solenoid closes the passageway between the solenoid and valves causing them to close Pressure from crankcase F00D12A TYPICAL RAVE VALVE CLOSED 1 Solenoide deactivated 2 Crankcase pressure 3 Check valve 03 36 Pressure from crankcase F00D13A TYPICAL RAVE VALVE OPEN 1 Solenoide activated 2 Crankcase pressure 3 Check valve Increasing Compression Ratio Machine the cylinder head to the dimensions shown in the illustration This modification results in a compression ratio of 14 1 Squish band diameter 88 5 mm 9 Cylinder diameter 88 0 mm THIS MODIFICATION REQUIRES THE USE OF HIGH OCTANE RACING FUEL The compression ratio of 14 1 is obtained by the modification of the cylinder head and milling 1 8 mm from the top of the cylinder oquish band clearance 95 to 1 00 mm MINIMUM www SeaDooManuals net SECTION 03 ENGINE PREPARATION Cylinder Modification Intake Modification Machine 1 8 mm from the top of the cylinder Using a porting tool modify the engine case in take port as shown in the illustration by removing Usi ting tool th haust and
64. PREPARATION Spark occurs as piston approches Top Dead Center F01D5GA FO1D6IA Exhaust Burnt gases Fresh charge Transfer port Intake Fresh charge COMBUSTION PROCESS Normal Combustion Since the beginning of this study we have spoken Flame front of air fuel mixture combustion rather than explo sion his combustion is a slow then accelerated burning of the mixture within the combustion chamber It is not an explosion Ignition occurs iiid with the firing of the spark plug This initial process generates heat and pressure which in turn is transmitted by conduction to the contiguous portion of the unburned mixture When this portion has reached the point of self ignition it starts to burn releasing more pressure L and heat UII Iraverses This burning action called a flame front travels at combustion a speed of approximately 30 m 100 ft per second chamber until all mixture is burned thus providing maxi rapidly mum piston thrust The end result is a quick build up in heat causing a quick build up in pressure forcing the piston downward 03 10 www SeaDooManuals net until mixture 15 completely burnt F01D5JA With all operating parameters correct normal combustion will take place However if for some reason the temperature inside the cylinder 15 In creased during combustion abnormal co
65. T CODES MODELS WITH CORRESPONDING BODY HULL PAINT CODES Model Name Model 1997 Number ullius ad Paint Code BRIGHT YELLOW 506 METALLIC FOREST GREEN M 510 BRIGHT METALLIC PURPLE M 521 T SS 5801880 1506 AN ENDER 5834 5661 5801 88 01 M 506 5521 5801880 MAGENTA 5812 92 01 5622 5801 88 01 TEAL 5870 94 01 5625 5801 88 01 B 176 GREEN 5852 93 01 GSX LTD 5625 M 519 B 176 5663 M508 ENGINE PAINT CODES 5818 5801 88 01 o 5001 88 01 5882 5801 88 01 M 506 YELLOW 5801 88 02 YELLOW 5803 90 01 Model Name Model s cai 1996 Number bg bed WHITE 5812 92 08 Paint Code WHITE 5812 92 08 2 5 5877 5801 88 01 511 657X WHITE 5812 92 08 5878 5801 88 01 WHITE 5812 92 08 5858 5859 M 506 WHITE 5812 92 08 SLM E I 947 5812 92 08 5865 5866 5801 88 01 M 506 5640 5801 88 01 M 512 EXHAUST SYSTEM PAINT CODES SERT WHITE 5812 92 08 Model Name Model Body Hull PURPLE 5852 93 02 Bombardier 1995 Number Paint Code BLUE 5803 90 02 5873 5801 3501 BLACK 5801 88 04 5874 5801 88 01 GRAY 5805 92 01 5870 94 01 5876 5801880 800 5856 M 506 5870 94 02 5857 5801 88 01 M 506 XP E G H PI TS 5863 5864 5801 88 01 X 5880 5801 88 01 M 506 02 6 www SeaDooManuals net SECTION 02 HULL PREPARATION Model Name Model Body Hull Model Name Model Body Hull 1994 Number Bombardier 1991 Number Bombardier Paint Code Paint Code SP J 5870 5801 801 5804 5801 88
66. W CAUTION If the ignition timing is adjusted too ad vanced this will cause serious damage to the engine The timing mark refer to the physical component position when the spark must occur The MPEM must be synchronized with the mark For in stance on a particular engine the timing correc tion may need to be advanced to 2 so that the mark aligns with timing mark pointer tool This 15 not the real spark advance just a correction for the tolerances of the mechanical components Knowing that you select with the programmer the higher or lower number to advance or retard the actual timing correction by referring to the fol lowing chart TIMING CORRECTION CHART Programmer Number Ignition Timing MPEM Correction 4 1 www SeaDooManuals net Examples a You found the flywheel mark advanced You must retard the ignition timing he programmer gives you the number 3 Referring to the chart number 3 returns a correction of 2 advanced and this is too much in this case You estimate the correction should be set to 1 advanced to align flywheel mark Back in the chart look to find 1 advanced This gives number 4 Enter this number with the programmer You recheck the timing with the timing light and if the mark is aligned ignition timing is properly set b You found the flywheel mark advanced You must retard the ignition timing he programmer gives you the number 3 Referring to the char
67. WATERCRAFT RACING eese 05 3 FEA 05 4 PACER EO 2 co E 05 5 AFTERMARKET MANUFACTURERS Sra Ra S ds 05 6 05 1 www SeaDooManuals net SECTION 05 MISCELLANEOUS EQUIVALENT WEIGHTS AND MEASURES CHART 1 Inch 2 54 Centimeters cm 1 Yard 2 914 Meter m 1 Meter 1 093 Yards AREA 1 Sq Foot 144 Sq Inches 929 03 cm 1 Sq Inch 2 6 4516 cm 1 cm 155 Sq Inch 1 Sq Foot 092 Sq Meter m 1 m 10 8 Sq Feet WEIGHT 1 Ounce 28 35 Grams g 1 Gram 03527 Ounce 1 Pound 4536 Kilogram kg 1 Kilogram 2 2046 Pounds VOLUME 1 Fl U S Ounce 29 574 Deciliter 0296 Liter 1 Fl U S Pint 473 18 Milliliters 4 7316 Deciliters 4732 Liter 1 Fl U S Quart 946 35 Milliliters 9 4633 Deciliters 9463 Liter 1 U S Gallon 128 oz 3 785 Liters 1 Cu Inch 16 387 Cu cm 1 Cu Centimeter 061 Cu Inch 1 Cu Foot 2 831 16 Cu Cm 1 Cu Decimeter 0353 Cu Foot 1 Cu Yard 7646 Cu Meter 1 Dry Quart 32 oz 1 101 Liters TEMPERATURE 32 Fahrenheit 0 Celsius 0 Fahrenheit 17 8 Celsius F c x 1 8 32 C F 32 1 8 05 2 www SeaDooManuals net SECTION 05 MISCELLANEOUS GLOSSARY OF TERMS IN PERSONAL WATERCRAFT RACING To wipe out to fall The bond flange is the overlapping mating section wh
68. a 7 PSI his negative pressure helps pull the remaining exhaust particles out of the cylinder It also helps pull the fresh charge up the transfer ports and into the cylinder SECTION 03 ENGINE PREPARATION F01D60A A 48 KPa 7 PSI As the sonic wave hits the converging end of the pipe a positive pressure wave is reflected back towards the exhaust port If the length of the pipe Is tuned correctly this positive pressure returns to the header pipe just before the exhaust port clos es and pushes the fresh charge that has escaped into the header pipe into the cylinder FO1D6SA The pipe then bleeds down to approximately at mospheric pressure and the cycle is repeated The design of the pipe depends upon many fac tors including bore stroke and desired effective operating RPM Because the sonic wave speed is fairly constant the length of the pipe is a large factor in control ling the engine RPM at which the pipe will be ef ficient A shorter pipe will result in higher RPM s but not necessarily more horsepower the pipe must be compatible with the other flow character istics of the engine carburetor size intake timing etc 03 49 www SeaDooManuals net SECTION 03 ENGINE PREPARATION Maximum efficiency is generally obtained by hav ing 1 pipe for each cylinder But this maximum point may be across a narrow and or high RPM range causing difficulties in driveability The 2 into 1 tuned pipes us
69. a dra matic increase of the specific fuel consumption Higher torque along with lower fuel consumption can be obtained at lower engine speeds if the time the exhaust port is open is shortened Bombardier Rotax has patented a remarkably sim ple system to automatically change the exhaust port height based on pressure in the exhaust sys tem Located above the exhaust port is a guillotine type slide valve This rectangular valve is connect ed by a shaft to a diaphragm which is working against a return spring One small passage in the cylinder just outside the exhaust port allow ex haust gas pressure to reach the diaphragm To the outside of the return spring is a red plastic adjustment knob Turning the adjustment in or out changes the preload on the return spring which in turn will change the RPM at which the RAVE valve opens and closes A18C01A Sliding valve Diaphragm Spring Exhaust port Adjustment knob O1 Co As the throttle is opened and the engine begins producing more power the pressure against the diaphragm will overcome the pressure of the re turn spring and the RAVE valve will open 03 18 hi F01D7GA VALVE FULLY OPENED F01D7HA VALVE FULLY CLOSED The RAVE valve does not allow an engine to make higher peak horsepower than an engine not so equipped it can however make moving the peak horsepower higher practical because of its effect on the rest of the power curve Item 2 i
70. a sharp or square corner in these areas It is important to realize that water conditions and repeated accelerations will increase cavitation Verify if engine speed is high but watercraft moves slowly due to reduced jet thrust Check jet pump components for damage Refer to appropriate model year Shop Manual IMPELLER Two types of impellers can be installed in the jet pump the regular fixed pitch and the progressive pitch impellers The meaning of the term pitch is the angle between the edge of the blade and the surface on which the impeller is sitting on or the angle at which impeller moves the water F01J4NA 1 Angle 2 Flat surface www SeaDooManuals net Regular Fixed Pitch The impeller pitch remains constant on all the blades The blades are straight with the same an gle from leading to trailing edges FO1J4NB 1 Leading edge 2 Trailing edge FO1J4SA 1 Leading edge 2 Straight blade 3 Trailing edge Progressive Pitch The impeller pitch changes progressively on each blade The blades are bent constantly or asym metrically with different angles at leading and trailing edges The blade bending is done by using a special fixture SECTION 04 PROPULSION SYSTEM F01J4TA 1 Leading edge 2 Constant bend 3 Trailing edge 4 Asymmetrical bend A low pitch leading edge is important for good ac celeration and a higher pitch on trailing edge will give better top speed Impeller
71. ammer and the other end to the safety lanyard switch on the craft Press the ON C button on programmer and enter your password Press 3 to choose Vehicle info in program Immer 4 Press 4 to choose Engine param O1 11 12 13 Press 2 to choose Timing adjust The programmer will display a number that 15 stored in the MPEM Press lt gt to choose yes for modify then press Enter Now punch in the number that corresponds to the degree you want for the ignition timing then press Enter Press Menu to go back one level Press 8 to choose Save Quit even if item no 8 Is not visible on the display it is active when you select it Press Enter to confirm yes you want to save modifications to the MPEM You must see Operation successful This confirms that the new timing data has been stored in the MPEM Unplug communication cable from safety lan yard switch on craft 14 Press Off to close the programmer At this point you can install the watercraft safety lanyard and start the engine to check the effect of the correction on the ignition timing If further ad justment is required repeat the procedure NOTE The MPEM features a permanent non volatile memory and keeps the ignition timing programmed even when the watercraft battery is disconnected www SeaDooManuals net 03 65 SECTION 03 ENGINE PREPARATION SPARK PLUG INFORMATION opark plug heat ranges are selec
72. an internal leak and it can be detected with Bottom End and Top End testing 03 40 www SeaDooManuals net Bottom End and Top End Remove the carburetor s and gasket s Make sure the surface of the intake manifold 587 657 and 717 engines or rotary valve cover 787 en gine are clean Install the intake plate s no 3 with fasteners from the kit and tighten adequately On engines with the RAVE system remove the RAVE valves and gaskets Install plates no 4 with fasteners from the kit and tighten adequately NOTE On engines with the RAVE system the boot and O ring can be checked for leakage with the valve in place Simply remove the cover to ex pose the boot Make sure the spark plugs are installed and tight en Block pulse hose using a hose pincher NOTE Do not block the rotary valve shaft hoses Install pump to the exhaust plate fitting F01B2XA 587 ENGINE 1 Intake plate 2 Plug pulse hose with a pincher 3 Exhaust plate SECTION 03 ENGINE PREPARATION F01B2YA 657 ENGINE 1 Intake plates 2 Plug pulse hose with a pincher 3 Exhaust plate F01B2ZA 717 ENGINE 1 Intake plates 2 Pulse hose blocked with a pincher 3 Exhaust plate 03 41 www SeaDooManuals net SECTION 03 ENGINE PREPARATION F01B30A 787 ENGINE 1 Intake plates 2 RAVE valve plates 3 Pulse hose blocked with a pincher 4 Exhaust plate Activate pump and pressurize engine to 34 kPa 5 PSI
73. arb Manifold pressure is a way of measuring the strength of engine suc tion Although air flow is increased initially there isn t enough air flow until high engine speeds to replace manifold pressure 03 74 Freer Air Intake Systems Free flowing unrestricted air intakes increase air flow but once again at low throttle openings may reduce manifold pressure Increasing air flow is a good thing but be aware that adjustments have to be made in your carb to compensate for pres sure changes Atmospheric Pressure Atmospheric pressure changes with altitude and temperature BN carbs adjust automatically to mi nor changes in either altitude or temperature in this way As air thins out for example less air is drawn through the engine which enrichens the air fuel mixture but there is also less pressure acting on the regulator diaphragm this tends to lean the air fuel mixture These 2 factors off set each other to a small degree but this effect must be taken into account when you consider read justment for a large change in altitude or temper ature Needle Valve Arm Needle valve arm adjustment is from the top surface of the arm being level with the cast sur face of the carb to a maximum of the surface of the arm raised 1 mm 0407 above the carb sur face The arm is a convenient way to make minor adjustments in pop off pressures Bending the arm upwards by the mentioned 1 mm 0407 will noticeably decrease pop off pre
74. asoline due to the hazard of fire Protect your eyes from the spray when the needle valve pops off 03 76 5 Pressurize the carb with the pump until the needle valve pops off Check at what pressure the valve closes and seals This illustrates qual ity of valve sealing Test the valve at least 3 times to assure an accurate reading Be sure to keep the needle valve wet The reason for wetting the needle valve is to du plicate actual conditions during operation When the engine is running the needle valve has gaso line running through to wet it and engine vibra tions to actually help the needle obtain a good seal As you adjust pop off pressure to tune your carb make changes in small increments only approxi mately 2 PSI because small changes in pop off can equate to big differences in engine perfor mance Increasing or decreasing pop off dra matically affects how the low speed jet performs Pop off enhances the fuel flow of the pilot jet Example The pilot jet is a no 100 and the pop off is 16 PSI If the pop off is increased to 20 PSI the amount of fuel that passes through the jet decreases even though the jet size re mains unchanged If the pop off was decreased to 13 PSI the no 100 jet would flow proportional ly more fuel The pilot jet and pop off work togeth er in the transition circuit As a rule of thumb adjusting pop off is for making big changes in the transition circuit the pilot jet is used for fine
75. ass and Superstock Class racing an aftermarket exhaust pipe and manifold are al lowed The muffler however must remain stock with no modifications When purchasing an after market pipe consult the manufacturer of the pipe to determine if the pipe is race legal by your race sanctioning body 5 Some pipes will fit your craft but may not be race legal because of inade quate head pipe cooling or mounting of the pipe requires relocation of the muffler Muffler reloca tion is illegal by several sanctioning bodies for Limited Class and Superstock Class racing 03 50 WATER FLOW REGULATOR VALVE All watercraft equipped with a 787 or 947 engines use a water flow regulator valve located on top of the muffler to control the amount of water inject ed into the exhaust system at the tuned pipe head and the muffler The purpose of this is two fold 1 It effectively controls the exhaust wave speed thereby creating a more useful or broader pow er curve 2 It cools the exhaust system and hoses which prevents heat damage NOTE The water injected in the muffler is not regulated by the valve it is controlled by a fitting located at the bottom of the valve which secure also the valve to the muffler The water regulator is calibrated for use on water craft which have no engine modifications The regulators works quite well on the stock water craft and provides a noticeable increase in perfor mance over models not so equipped If th
76. ation with the other also chang ing the ignition timing for the PTO cylinder and the rotary valve timing for the MAG cylinder F01D1NA 1 Main journal alignment here Counterweights can also be twisted on connect ing rod journal on any or both cylinders j WA F01D1NB 2 1 Connecting rod journal alignment here Crankshaft Alignment at Center Main Journal To accurately check crankshaft alignment pro ceed as follows Remove magneto housing cover SECTION 03 ENGINE PREPARATION Remove MAG flywheel nut and also the mag neto rotor for the 787 engine Install Bombardier degree wheel P N 295 000 007 on crankshaft end Hand tighten nut only Remove both spark plugs nstall a TDC gauge P N 295 000 143 in spark plug hole on MAG cylinder side Bring MAG piston at Top Dead Center As a needle pointer secure a wire with a cover screw and a washer 4 TDC gauge Degree wheel Hand tighten nut Needle pointer KON Rotate degree wheel NOT crankshaft so that needle pointer reads 360 Remove IDC gauge and install on PTO side Bring PTO piston at Top Dead Center Interval between cylinders must be exactly 180 therefore needle pointer must indicate 180 on degree wheel 360 180 180 Any other reading indicates a misaligned crank shaft 03 45 www SeaDooManuals net SECTION 03 ENGINE PREPARATION
77. can be corrected by surfacing with a fine sandpaper on a surface plate Surface part against oiled sandpaper Inspect bearings Check for scoring pitting chip ping or other evidence of wear Make sure plastic cage on bigger bearing 15 not melted Rotate them and make sure they turn smoothly Check for presence of brass filings in gear hous Ing Visually check gear wear pattern on gears It should be even on each tooth for the complete rotation of the gears Uneven wear could indicate a bent shaft check for deflection Replace gear if damaged There should be no deflection in the rotary valve shaft If there is the shaft must be replaced Rotary Valve Cover Clearance The clearance between the rotary valve and the cover must be 0 30 0 05 mm 012 002 in NOTE If the clearance is below 0 25 mm 010 in this could create an overheating situation and if the clearance is over 0 35 mm 014 in this could create a hard starting situation There is two methods to verify rotary valve cover clearance One with a 45 feeler gauge the other one with a solder 45 Feeler Gauge Method Remove O ring from rotary valve cover Remove intake manifold from rotary valve cover except 787 engine Reinstall cover in place WITHOUT its O ring and torque screws to 20 Nem 15 Ibfeft Feeler gauge blade from 0 25 mm 010 in to 0 35 mm 014 in thickness should fit between rotary valve and cover Insert feeler gauge blade th
78. craft Your watercraft must conform to association specifica tions The IJSBA is the sanctioning association for the United States You can contact them at the ad dress listed below The IJSBA will also be able to provide you with the contact information for the affiliate association in your country as well as pro moters in your region A membership in the association sanctioning the event is mandatory before competing in a race DA INTERNATIONAL JET SPORTS BOATING ASSOCIATION 1239 EAST WARNER AVENUE SANTA ANA CA 92705 PHONE 714 751 4277 FAX 714 751 8418 www SeaDooManuals net SECTION 01 GENERAL RACING INFORMATION TABLE OF CONTENTS PREPARING FOR RACE DAY ui 01 2 PREPARING FOR A SAFETY INSPECTION 01 5 PRERACE MAINTENANCE S 01 6 MAINTENANCE BETWEEN RACES uuu 01 7 EQUIPMENT AND SPARE PARTS BRING TO THE 01 8 ui iii uim ENTIAT O c E 01 8 INTERACTION WITH RACE OFFICIALS e 01 9 SPONSORSHIP AND SOLICITATION U 01 10 THE PROFESSIONALS POINT OF VIEW 01 11 01 1 www SeaDooManuals net SECTION 01 GENERAL RACING INFORMATION PREPARING FOR RACE DAY ACTIVITIES 1 Joining the Sanctioning Body All legitimate races are conducted under the guid ance of a given sanctioning body The most com m
79. der to check for an illegal rotary valve Also the head may have to be removed to check for porting in limited classes or bore and stroke measurements for displacement limits in the modified class If you are using your boat in another racing class later that day inform the inspector he will have you come back after your last race Don t forget to come back he inspector keeps close notes and you will be disqualified 1 you do not return 13 Emergency Rescue During the race several Course Marshals will be riding the course watching for missed buoys and fallen riders In the event of an accident and you go down wave your arm over your head if you are OK Other riders can see you easier and the Course Marshal will pull you back to your boat If you are hurt the Course Marshal will be in the water as soon as they reach you At that time the race may be red flagged The Course Marshals will then determine if a backboard is needed Once they get you to shore the EMT will take over and transport if necessary Injuries requiring medical attention require an accident report be made to the promoter Always make sure that you have all your emer gency information written down Designate a member of your team to get this information to the EMT as soon as possible The information sheet must contain your full name address and phone number allergies blood type person to contact in an emergency and phone number
80. e watercraft is not being raced but modifications are made to the engine such as increased com pression changes in port timing etc the water regulator valve will not deliver the correct amount of water for optimum performance Recalibrating the regulator water flow will require most users to experiment with different size holes being drilled into the regulator then threading and fitting the holes with jets Various size Jets will then be tried until the best performance is found The water regulator valve is legal for competition use in the IJSBA Any valves used within the en tire engine cooling system must be of the fixed type or fully automatic type no manually operated valves are permitted In some situations it may be desirable to hard Jet the exhaust system www SeaDooManuals net SECTION 03 ENGINE PREPARATION 2 At the exhaust tuned head pipe there is a 1 4 in fitting already in use that was used to accept the regulated water supply from the now dis carded water flow regulator valve Remove the hose from the fitting at the head pipe and thread the fitting to accept a Mikuni main jet 3 he engine is equipped with a 1 2 in water inlet hose coming from the jet jump Between the jet pump and the engine there is a 1 4 in out side diameter T fitting and hose currently in stalled The fitting and hose was used to supply water to the now discarded water regulator At tach a 1 4 in T fitting to the hose in place of the wa
81. e manufacturers based on their previous performance records Sea Doo takes no responsibility for parts and products not installed as original equipment n fact the use of most aftermarket parts will invalidate the vehicle warranty as provided by law USE AFTERMARKET PARTS AT YOUR OWN RISK BEACH HOUSE EXPRESS Racing Parts and Sponsons EVOLUTION MARINE Flame Arresters and Performance Parts Brian Bevins 301 North Gulf Drive Bradenton Beach FL 34217 Phone 941 779 1151 Fax 941 778 1886 www bv net beachhouse sponsons FACTORY PIPE Exhaust Systems 150 Parducci Road Ukiah CA 95428 Phone 707 463 1322 Fax 707 463 1384 www factorypipe com JET DYNAMICS Propulsion Components and Intake Grates Rt 1 P O Box 1762 Burley ID 83318 Phone 208 678 7038 Fax 208 654 2446 MSD IGNITIONS Ignition Components 12120 Esther Lama Suite 114 Paso 79936 Phone 915 857 5200 Fax 915 858 9241 www msdignition com NOVI PERFORMANCE PRODUCTS Race Parts and Flame Arresters Lee Robison 2 Rutledge Circle Fletcher NC 28732 Phone 704 687 7555 Fax 704 687 7556 05 6 215 St Andrews Road Newport Beach CA 92663 Phone 714 722 8968 Fax 714 722 8968 HOT PRODUCTS Racing Parts 8949 Kenamar Dr no 111 oan Diego CA 92121 Phone 619 566 4454 Fax 619 566 3625 www exceed com hot1 MILLER RACING Big Bore and Stroker Motors Mel Miller 9941 Belcher St Downey CA
82. e suction within the carb the fuel pressure at the needle valve and the atmospheric pressure are great enough to overcome the arm spring pressure the needle valve will open allowing fuel under pres sure from the pump to enter the fuel chamber This combined force is commonly referred to as pop off pressure The force required to pop the needle valve off the seat NOTE As soon as the fuel chamber has been filled fuel flow into the chamber ceases and the carb returns excess fuel via a restriction to the fuel tank There are a number of factors that can modify or change the effectiveness of an engine to over come this pop off pressure The engines ability to create a strong suction signal within the carb and the outside air pressure are 2 variable factors Engines can be modified in many ways that can Increase or in most instances decrease the suc tion generated Listed here are examples of changes and the effect on engine suction Modified Porting Modified porting from mild to wild can have the effect in most cases of reducing suction at lower throttle openings and with it hindering carbure tion and clean running in the engine s lower RPM range Hopefully the porting is good and will in crease air flow at higher RPM s for better carbure tor response and increased power Freer Exhaust Systems Freer exhaust systems decrease suction Even though they flow more freely they reduce mani fold pressure within the c
83. e sure to reinstall it If this shim is required for your watercraft and not reinstalled engine and jet pump alignment will be altered FUNCTIONS OF THE VARIABLE TRIM SYSTEM VTS To obtain optimal performance push VTS button located on left side of handlebar or turn knob on left side of pump body depending on the model of watercraft This adjustment changes the jet pump steering nozzle position which compensates for load and thrust When the nozzle is up the bow of the watercraft comes up 04 12 1 Bow up 2 Push on VTS button UP position 3 Nozzle up When the nozzle is down the bow comes down F01J5BC 1 Push on VTS button DOWN position 2 Bow down 3 Nozzle down According to boat load and water conditions the driver can trim the watercraft as desired W CAUTION Trim ring and or nozzle must not interfere at any position Damage to cables and or ven turi housing will occur if adjustments are not done properly For adjustment procedures refer to appropriate model year Shop Manual www SeaDooManuals net PROPULSION SYSTEM MAINTENANCE To obtain optimum efficiency of jet pump and to eliminate backlash in propulsion and drive sys tem the following maintenance items must be checked regularly Verify oil condition and replace oil regularly A whitish oil indicates water contamination Use only SEA DOO JET PUMP SYNTHETIC OIL P N 293 600 01 1 Using a grease gun carefu
84. ed on Sea Doo water craft are very accurately tuned for the overall de sign of these particular engines NOTE Changing the tuned pipe for an aftermar ket unit will usually change RPM and torque of the engine An impeller change to compliment your new tuned pipe will probably be necessary Water Injected Exhaust System several factors necessitate the use of a water cooled water injected tuned exhaust system One major concern is overall bilge temperature which is kept low by keeping the part of the tuned pipe closest to the engine jacketed with water and the remainder of the exhaust system cool by Injecting water directly into the exhaust stream Injecting water into the exhaust system not only helps keep the exhaust system cool but also changes the characteristics of the sonic wave in the tuned pipe The water injected exhaust sys tem reduces exhaust gas temperature therefore Increasing exhaust gas density in the tuned pipe he sonic wave moves slower in this cooled denser air so it takes longer to reflect back to the exhaust port The net effect is that the tuned pipe can be shorter yet achieving the same results as a longer dry tuned pipe By changing the amount of water injected into the exhaust stream the characteristics of the engine power band can be altered It is important that enough water is injected into the exhaust stream to keep the rubber hoses and muffler from dam age due to excessive heat In Limited Cl
85. egulator diaphragm 7 Pump diaphragm Arm 8 Filter 19 Arm spring 9 Restricter 20 Fuel chamber 21 Vent to atmosphere 10 Fuel return 11 Inner venturi 22 Low speed screw 03 72 www SeaDooManuals net grease A Sy per 13 2 NS 72 Synthetic grease y N Synthetic 257 See 1 x F01F05S 1 Needle valve 2 Low speed screw 3 Diaphragm 4 Pump body 5 Filter 6 Choke plate 7 Throttle plate 8 9 Main jet 10 Pilot Jet 11 Check valve assembly SECTION 03 ENGINE PREPARATION Loctite 242 9 20 Nem 15 Ibfeft 12 Choke valve 13 O ring 14 High speed screw 15 Idle speed screw 16 Pump cover 1 7 Gasket 18 Diaphragm 19 Diaphragm 20 Screw 2 per carb 21 Lock washer 03 73 www SeaDooManuals net SECTION 03 ENGINE PREPARATION Carburetor Tuning Tuning the Super BN carburetor s can be a fairly simple matter if you look at it with a logical per spective As modern and technologically ad vanced as the Super BN is it is still a fuel regulator due to the fact that fuel entry into the carb and fuel delivery is regulated by a spring and diaphragm system Using the cutaway drawing as a reference you can see that as fuel is drawn out of the fuel chamber atmospheric pressure push es inward on the regulator diaphragm moving it against the spring pressure on the needle valve arm When the combined forces th
86. enters the cooling Jackets of the cylinders through small passages under the exhaust ports The flow of water through the exhaust system has changed slightly from the 1988 91 yellow en gines to the 1992 97 white engines however the most important point is that on either type of en gine the water 15 still pre heated by the exhaust system before entering the engine cooling jack ets On the 717 and 787 engines the water first enters the cylinder head unlike previous models The cylinder head cooling jacket has been divided into 2 sections One side of the head s water jacket exhaust side has cool incoming water circulate around the combustion chambers then into the tuned pipe and exhaust manifold cooling jacket The preheated water then enters the cooling ets of the cylinders From the cylinders the water flows upward through calculated holes to the out let side of the cylinder head The outlet side of the cylinder head s cooling jacket also houses the en gine temperature sensor where the now hot wa ter escapes through the engine water outlet hose SECTION 03 ENGINE PREPARATION some aftermarket companies may suggest that the cooling system be re routed to feed cold wa ter directly to the engine instead of allowing the exhaust system to warm it first This change should be approached with caution as random changes without adequate testing and develop ment could be detrimental to the engine Chang ing the routing
87. entification To identify the impellers refer to the following il lustration and charts F02J0VA 1 Stamped part number www SeaDooManuals net SECTION 04 PROPULSION SYSTEM IMPELLER APPLICATION CHART MODEL SP zi stiess 271000030 _ sess 271000182 stainless 271000445 271 000 351 1623 771 000 381 1725 271 000 331 1224 271 000 458 271 000 497 m 271 000 470 04 5807 1993 14 21 stainless 5871 1994 11 26 stainless SPX 5874 1995 11 23 stainless www SeaDooManuals net SECTION 04 PROPULSION SYSTEM IMPELLER APPLICATION CHART MODEL MODEL NUMBER YEAR PITCH ANGLE MATERIAL 5865 5866 5867 1996 11 24 271 000 470 5641 1997 11 22 271 000 470 5860 1992 771 000 123 5861 1993 771 000 123 NOTE Impeller may be interchangeable to suit the required performance of the course type 04 8 www SeaDooManuals net SECTION 04 PROPULSION SYSTEM IMPELLER SPECIFICATIONS AND BOOT APPLICATIONS 271 000 015 271 000 230 Ore se opi 271 000 114 satin finish stainless steel 14 21 progressive pitch 2 1 000 104 satin finish stainless steel 2 1 000 313 ring 2 1 000 016 18 8 Cast aluminum 271 000 114 271 000 030 ge pen 271 000 114 satin finish stainless steel 271 000 299 ugue cp 271 000 114 satin finish stainless steel 271 000 307 271 000 305 satin finish stainless steel 271 000 280 jc Pug CR 271 000 305 satin finish stainless s
88. ere the deck upper and hull Bond Flange lower portions are joined Buoy Floating object anchored in the water designating race course Couce Marchai An official located on the race course to help control the race as well as to assist downed riders Deck The structural body of the watercraft located above the bond flange Heiden The person that holds your watercraft on the starting line prior to the start of the Holeshot The process of arriving at the first turn ahead of the competition in a race Hull The structural portion of the boat below the bond flange An obstacle used in closed course racing that consists of row of tires which Log Jump riders must pass over Pit Area Area used by riders and mechanics to make repairs store watercraft etc Porpoise The act of a watercraft nose pitching up and down in the water Race Director Person responsible for organizing a race Com A person or group that provides support to a rider promoter or association usually P in exchange for promotion Area near the starting line where riders and their watercraft wait for their ging scheduled race ke The area where the schedule of events rider starting and finishing positions are Pit Board posted Permanently affixed identification number serial number affixed to the hull NOTE Carbon fiber hulls do not have Hull Id numbers a number will be assigned by the sanctioning body for these
89. es safety responsi bility and attitude both on and off the race course You must always be a positive role model While racing fear can not be in your vocabulary and challenge you accept on a one to one basis Your striving each day to improve upon the talents that people may think comes naturally My commitment and conditioning to be a Pro Runabout racer has put me up front in my class A class that many people dare not adventure for fear of where it may or may not lead them Take the challenge it may bring out the best in you Kelly Kurpil 1996 IJSBA Pro Woman Runabout National Champion 01 13 www SeaDooManuals net SECTION 02 HULL PREPARATION TABLE OF CONTENTS PREPARING THE HULL FOR INSPECTION IN DUUM ETUR 02 2 MEASURING THE HULL cnn X 02 2 THE RULE ec S SEEE nE4 Gw M 02 2 FALNIN G i c 02 3 CONGEPTIMPAINTING PROCEDURE u ull l ua dium 02 3 PAINTING PROCEDURE M 02 4 SEA DOO PAINT es e 02 5 STORAGE COVER PAINT CODES mun MEA INDIRIM MUI MEDIE ariii 02 6 E NGINE FAINT CODE uitium ce co sacra ESPRIME 02 6 EXHAUST SYSTEM PAINT CODESu uuu UU RDUM arca Utm IN NEM IN n ESOS ME 02 6 MODELS WITH CORRESPONDING BODY HULL PAINT CODES 02 6 SEALING OF
90. etent pro fessional Proper installation and adjustment will save time money and aggravation NOTE In most cases your new Super BN Carbu retor will be installed in conjunction with an after market manifold and flame arrestor air filter system We recommend using this manual to gether with the appropriate model year Shop Manual for your watercraft and the instructions from the aftermarket manifold manufacturer to help you with the installation and tuning of the BN carburetor system www SeaDooManuals net Basic Instructions 1 Use a new gasket between the carburetor s and intake manifold 2 Use flat washers and lock nuts to secure the carburetor s 3 Be sure that the fuel lines are of the correct di ameter for the carb fittings Secure all hose connections with cable ties and proper clamps 4 When installing the throttle cable be sure to securely tighten the jam nuts Allow a small amount of free play at the throttle lever Check to see if the throttle is opened as the handlebar is turned from side to side correct the cable routing if necessary W CAUTION Heavy duty carburetor cleaner may be harmful to rubber parts O rings etc There fore it is recommended to remove those parts prior to cleaning W CAUTION Be careful at carburetor cleaning not to re move paint Paint removal will cause carbu retor to corrode very rapidly Repaint if necessary SECTION 03 ENGINE PREPARATION External C
91. for easier maintenance 2 It has an integral fuel filter 3 The fuel pump capacity is increased by almost 2096 4 Air flow is increased by 9 5 It is easily tunable with replaceable jets in a wide range of sizes and an array of other tun Ing components With the introduction of the Super BN Series of carburetors Mikuni American has made re newed commitment to the watercraft industry by researching carburetor tuning applications and disseminating this information to the consumer In the past jetting information was available through many different sources but unfortunately there were as many different recommendations as there were sources With this information we will be able to provide a reliable and consistent source of approved technical details 03 68 Carburetor Installation FO1F29A MIKUNI SUPER BN38 DUAL CARBURETOR SET FOR HIGH PERFORMANCE APPLICATIONS W CAUTION Exercise caution when changing carburetion components and any time you work with the fuel system on your watercraft Work in a well ventilated area Do not turn the engine over while fuel lines are disconnected mediately clean up any fuel spill that might occur during carb installation NOTE As when installing any performance prod uct a degree of mechanical ability is required If after reviewing the parts and instructions you do not feel that you can properly complete this instal lation take your watercraft to a comp
92. ge www SeaDooManuals net FUNCTION OF AN EXHAUST SYSTEM Volumetric efficiency V E of an engine is the ra tio of the actual amount of air drawn into an en gine versus the capacity of the engine The natural V E of a 2 stroke is about 6596 This means a 250 cc cylinder only draws in about 160 cc of air The HP output of an engine can be raised by increasing the V E of the engine The most notable method of raising V E is the use of a correctly tuned expansion chamber or tuned pipe If the exhaust port is emptied into the open atmosphere much of the fresh air fuel charge rushing up the transfer ports is expelled out of the exhaust port and lost To prevent this charge from being lost a tuned chamber is attached to the ex haust port The tuned chamber uses sonic wave motion which is separate from the exhaust parti cles and fresh charge particles to move the parti cles around this is like waves in water moving a cork When the exhaust port is opened a sonic or sound wave Is generated by the high pressure ex haust gases expanding into the header pipe The speed of sound at exhaust temperature is about 518 meters 1700 ft per second F01D6PA Sonic wave initiated as exhaust port opens Tailpipe or stinger Head pipe Diverging cone Mid section Converging cone amp Co N This wave travels down the header pipe and ex pands into the diverging cone causing a negative pressure of about 48 kP
93. ght and or stronger parts for racing purposes such as seats and stor age covers hese are worth considering These light weight parts are illegal in the Limited Class Be sure the parts you are installing are within the rules SPONSON KITS Advantages of the Sponson improved handling reduces spin out Holds better in corners more stability NOTE The sponsons on the Stock Sea Doo wa tercraft protrude beyond the width of the hull bond flange Because of this it is necessary that the sponsons be filed or ground down to fit within the bond flange in order to be race legal The edges must be radiused to prevent a hazard to other riders There are long type sponsons and short type sponsons available in kits They do work well when interchanged within the same type It 15 only a matter of preference 02 8 Available Kits Short Concave Sponsons 295 500 248 BLUE PURPLE 295 500 194 GREEN 295 500 195 MAGENTA 295 500 329 BLACK Short V shaped Sponsons 295 500 249 ORANGE 295 500 168 GREEN 299 500 252 LIGHT GREY Long Sponsons 295 500 254 GREY 29b 500 330 BLACK Installation Guidelines The following pertain to all types of sponsons The sponson holes location are given for short type For long type it is recommended to experiment to obtain what you require Minor adjustments in angle or height location of the sponson can have a tremendous effect on handling and speed The position illustrated is
94. gs You can refer to the pressure chart further along in this section to obtain ap proximate pop off pressures with spring pressure and needle valve combinations 03 70 NOTE It is important to NOT select a needle valve that is too small for your application due to the fact that the needle valve can be a limiting fac tor in maximum fuel flow In other words in some applications engines require more fuel than small needle valves can deliver The needle valve sizes in Mikuni special set carbs have been carefully se lected and should not be decreased However in the case of watercraft with very high fuel de mands it may be necessary to increase the nee dle valve size Keep in mind that when the needle valve size is changed it will affect the pop off pres sure W CAUTION It is recommended that you select an arm spring that is the correct length rather than cutting or stretching an existing spring the results are more consistent over the long run Cut or stretched springs tend to change strength over time The anti siphon valve is located in the valve body assembly attached directly above the high speed jet It is responsible for retaining fuel in the fuel chamber when the engine is shut off When the engine 15 running suction will cause the anti siphon valve to flex allowing fuel to flow to the jet If the valve becomes worn or does not seal correctly the symptoms will appear as a rich condition from 1 2 to ful
95. hampion 1996 IJSBA Pro Runabout 785 World Champion Header Kelly Kurpil As a Pro Runabout racer each day of training test ing and racing has taught me more Conditioning has become a big part of my daily routine learned early on while racing in the Modified Divi sion against the men that physical strength plays a major role in being competitive Each day in clude a weight training program with my personal trainer for strength and stamina Weight training has given me the strength need to compete on a professional level use this training to my ad vantage to improve my endurance and cornering skills This type of conditioning has taught me dedication motivation responsibility and self con trol The lessons have learned have helped me sharpen the skills need to be a competitive racer www SeaDooManuals net SECTION 01 GENERAL RACING INFORMATION Racing may not be for everyone because of the commitment involved But for me feel racing brings out the best in me and builds physical en durance knew at my first race as a novice when the rubberband snapped that my life would never be the same again It takes a special individual to pursue an avenue of contrast excitement and dis appointment However that s what racings all about Being a Pro Runabout racer is a big responsibility Racing impacts every part of your life feel as does Sea Doo that the image project to others must be positive This includ
96. harged battery and jumper cables Quick drying epoxy or fiberglass repair kit Various size hose clamps Locking ties of assorted sizes oafety wire Duct tape and electrical tape Waterproof silicone sealer Assorted nuts and bolts grease gun with grease O O 00 1001 BW gt o cL NO O 1 PIT AREA PRESENTATION Your pit area is of major importance in many ways Race teams that are well financed actually pay the promoters to place large tents with sponsor names on them at the most advantageous loca tions on the beach his allows them greater me dia exposure by film crews and easy access to the water for their racers For these same reasons and more your pit loca tion Is just as important Your choice for pit location should be based on the following factors Weigh these factors in your mind and make the best possible choice given the circumstances 1 You need to set up where you will receive the greatest amount of exposure to the spectators media and well financed race teams You need to be recognized for your professional appear ance your attention to small details and your finishing position by all of these people Setting up next to large race teams will allow you to watch and learn from them When people come to see these teams they will also see yOu 2 You must be able to get your boat to and from
97. he case of the Mikuni BN carburetor the main restriction is considered to be the throttle plate When the throttle plate is closed it offers the greatest amount of restriction and manifold pres sure Is high As the throttle plate is opened the restriction is reduced and manifold pressure de creases The carburetor sees manifold pressure as a po tentially strong suction drawing on any exposed openings within the carb As the throttle 15 opened more internal openings are exposed to this suction To begin with only the low speed fuel outlet is exposed but as the throttle is opened further the bypass holes and the high speed fuel from the inner venturi are exposed to the suction At this point with the throttle wide open if there was no fuel in the carb the engine would not rev up and because the throttle plate was open fully the manifold pressure would be very low However we do have fuel and the en gine does rev drawing an increasing amount of air velocity through the carb As the air velocity through the carb increases it replaces manifold pressure as the suction force within the carbure tor What are the dynamics of manifold pressure and air velocity As the engine is idling we know that manifold pressure is high and there is good signal strength within the carb which makes adjust ment easy As the throttle is opened quickly man ifold pressure disappears and if the jetting within the carb is correct the engine revs qu
98. he hull and ride plate to eliminate any possible inlet flow restrictions The water in let and ride plate must have the surfaces sealed and blended Certain aftermarket intake grates will enhance the performance of your watercraft selecting the correct intake grate will depend on your intended use and type of racing A careful choice 15 highly suggested NOTE Race legal intake grates may not extend more than 12 mm 0 473 in below the flat plane surface of the pump intake area Axial Flow Jet Pump The Bombardier Formula Jet pump 15 an axial flow single stage design This term axial flow is defined as a single impeller axially driven by a cen trally located shaft The impeller will transfer a designated volume of water each revolution through the pump The axial flow jet pump characteristics are low pressure high flow small size of pump high RPM www SeaDooManuals net F01J4PA Oil reservoirs Impeller shaft end play Venturi Stator vanes Impeller Co NOTE Watercraft models equipped from the fac tory with the new composite jet pump housing can not legally use the aluminum type housing from previous models for IJSBA competition events Impeller The impeller is enclosed in the housing and it cre ates a dynamic force The thrust created by the impeller alone is minor but it has a high power absorption he stator vane and venturi are essen t
99. he inlet or pump be comes incapable of keeping up with the flow Therefore a negative pressure within the system occurs creating gas vapor and ultimately cavita tion As these gas vapor bubbles implode they generate enough force to remove microscopic particles of material within the pump assembly This usually can be seen in the form of discolored areas or trails within the pump assembly on the stator vanes or impeller These areas look as though they have been sana blasted A certain degree of cavitation is an accepted oc currence with a water jet propulsion system However some changes within the pump can re duce cavitation such as replacing a thick bladed aluminum impeller with a thin bladed stainless steel impeller removing any scratches or dents In the housing impeller or replacing wear ring If worn Chamfer and or radius leading edges of stator vanes Using a straight file break the square edge on both sides of stator vane to about 1 3 mm 050 in wide then use about a 2 foot strip of 1 inch wide sandpaper 100 grit min and drape sandpaper over stator vane area already filed by placing one end of sandpaper in one tunnel and the other end in the tunnel directly adjacent to the first and fin ish dressing the leading edge This procedure should be done to both the leading and trailing edges of stator vanes 04 4 F01J4MA 1 Reworked vanes 2 Tunnel 3 Break these edges slightly 4 Be careful not to make
100. he races you have competed in complete with your finishing positions and overall titles Conclude your resume with a listing of your previous sponsors their product line and any major media coverage that you have received that would be advantageous for a sponsor to know The complexity of your sponsorship proposal will vary quite noticeably depending upon the level of racing at which you are competing Racers who are competing in regional events or are well back in the standings on the National Tour are not able to get the high dollar support that requires an exhaustive detailed proposal Most proposals should list the various levels of support that are available for the sponsor within your racing pro gram Each level of support should be followed by a statement of the service you will provide for that support There are many ways a sponsor can support your racing program and there are many services you can provide for that support Types of support can include 1 Products such as racing equipment for your boat racing apparel safety equipment or transport equipment trailers totes 2 Services including repair work or modifications to your engine hull jet pump or paint jobs for your boat and trailer 3 Cash for entry fees and other types of expenses The services you can provide for this support is only limited to your imagination Innovative new ideas are what businesses are looking for The better job you
101. hulls Hull Id Number A sign held up by the starter signaling the riders to start their engines During the 2 Card display of the 2 card the rider may call a 2 minute hold in the event of mechanical trouble which will delay the start of the race The 2 card is turned around to display the number 1 to the riders indicating that the race Is about to begin At this point a 2 minute hold is no longer allowed ara Indicates that the rubber band will snap within 1 to 5 seconds to start the race Displayed Sideways 05 3 1 Card www SeaDooManuals net SECTION 05 MISCELLANEOUS GLOSSARY OF TERMS IN PERSONAL WATERCRAFT RACING CONTD During the display of the 2 card a racer may call a two minute hold in the event of problems on the starting line for example not being able to start the watercraft Only the racer may call the two minute hold by holding up his hand displaying 2 2 Minute Hold fingers The rider watercraft and holders must be on the line to call a 2 minute hold Once the two minute hold is acknowledged the rider has two minutes to be ready to race If after two minutes the racer is not ready to race the race will proceed with out him Tech Inspection Sticker A sticker affixed to the watercraft to indicate that it has passed safety inspection Post Race Technnical All qualifying riders must report to the technical inspector after the event to have Inspection their watercraft checked for rule compliance
102. ial to create thrust and to straighten out twisted water coming of spinning impeller Stator The function of the stator is to transform the dy namic force created by the impeller into forward thrust The design principle is similar to the impeller al though the stator vanes are in a fixed position Venturi The venturi function is to increase the fluid veloc ity using static pressure to generate the thrust Without the venturi there would be very little thrust The venturi outlet diameter can be adjust ed to compliment the engine tuning and impeller you have selected Generally speaking a slightly larger 1 2 mm outlet will improve acceleration and should give better performance for closed course competition SECTION 04 PROPULSION SYSTEM Nozzle The handlebar pivots the jet pump nozzle which controls the watercraft direction These 2 items the handlebar and nozzle must be adjusted properly to obtain optimum control of the watercraft The steering system alignment is most important to ensure the adequate control of the watercraft Ensure handlebar and jet pump nozzle oper ate freely from side to side and that jet pump nozzle does not contact the side of venturi housing For alignment procedures refer to appropriate model year Shop Manual VENTILATION AIR LEAK Ventilation is caused by air being sucked through jet pump which will reduce performance of the pump Pump ventilation reduces accelerat
103. ickly and air velocity increases to accelerate you on your way 03 75 www SeaDooManuals net SECTION 03 ENGINE PREPARATION Now you can see the importance of the transition circuit it is there to aid in the transition from high manifold pressure to high air velocity Correct ad justment of the transition circuit is vital to smooth acceleration and good performance Testing Pop off Pressure Testing pop off pressure requires a pump gauge tester such as the one available from Bombardier F01BOXA PUMP GAUGE TESTER P N 295 000 114 The gauge should be calibrated in at least 1 2 PSI increments and read up to 30 PSI The readings taken from the gauge are used for comparison be fore and after changes so the actual accuracy of the gauge 15 not critical The pop off pressure chart in this section shows very accurate PSI values between needle valve sizes and spring pressures Before making any changes in pop off test your carb and see how it compares to the chart Steps in Testing 1 Attach the pump hose to the fuel inlet on the carb 2 Cover or in some way completely plug the fuel return line 3 is recommended that the regulator dia phragm and its cover be removed during test Ing 4 During testing it 15 important to obtain consis tent readings accomplish this it 15 neces sary to keep the needle valve wet Use BOMBARDIER LUBE P N 293 600 016 to wet the needle valve W CAUTION Do not use g
104. imum throttle opening Is being attained Lubricate the throttle cable at this time 8 Clean or replace the flame arrester as neces Sary 9 Engine bed plate bolts should be checked for tightness 10 Check all exhaust system components for cracks or signs of fatigue Pay close attention to rubber couplers exhaust pipe and exhaust manifold mounting bolts 11 Service the battery and check for clean corro sion free battery cable connections make sure the battery is fully charged 12 Grease the PTO flywheel and the drive shaft seal carrier if applicable at their grease fit tings If the seal is damaged replace it 13 Check the hull and deck for signs of cracking or damage If the bottom of the hull has been damaged or scraped repair should be made to restore the configuration to it s original shape 14 The impeller housing should be removed to al low for a close inspection of the jet pump and related parts Impeller clearance stator vane and general pump condition should also be checked Remove the drive shaft and inspect the splines Check for correct engine to pump alignment Grease all necessary components during reassembly Lubricate the steering stem steering support and cables Upon com pletion check for proper steering cable and trim cable adjustments NOTE Poor engine to jet pump alignment will cause excessive vibration and loss of horsepower 15 Check the intake grate for damage and tight ness
105. ind line 147 on degree wheel and mark crankcase at this point OSE ove oce 9 w 0i 0e 9 osz 09 at o 9 FO1D3DC OPENING MARK Step 1 Bottom of MAG inlet port Align 360 line of degree wheel Step Find 147 on degree wheel and mark here NOTE Do not rotate the crankshaft For closing mark first align 360 line of degree wheel with TOP of MAG side inlet port Then find 65 line on degree wheel and mark crankcase at this point 280 30 280 eT gt 90 79 60 6 gt 93 9 02 9 90 200 210 22 10 180 150 w 1 N gl oy 062 aye osz o ts 0 EE f ge gj 99 CLOSING MARK Step 1 Top of MAG inlet port Align 360 line of degree wheel Step 2 Find 65 on degree wheel and mark here Remove degree wheel SECTION 03 ENGINE PREPARATION Position rotary valve on shaft splines to have edges as close as possible to these marks with the MAG piston at TDC NOTE When checking the timing with the MAG side piston at Top Dead Center the rotary valve shaft should be lightly held in a clockwise position to take up any gear lash that may be present The valve is asymmetrical and can be flipped over to obtain a better timing position There is a possibil ity that exact timing cannot be reached by this method When this occurs the rotary valve shaf
106. ion and will be most noticeable during initial and low speed accelerations Engine RPM will increase tremendously with very little increase in water craft speed This condition feels much the same as a slipping clutch in a car or motorcycle Jet pump ventilation is commonly traced to a poor seal between ride shoe and hull To determine if jet pump is ventilating first verify the following Verify if the watercraft accelerates quickly when depressing throttle lever Verify if the engine has a consistent top RPM Verify impeller impeller wear ring and pump housing for wear and or damage or if debris is caught in the grate or around drive shaft Always remove the safety lanyard from wa tercraft prior cleaning the propulsion sys tem to avoid any accidental engine starting 04 3 www SeaDooManuals net SECTION 04 PROPULSION SYSTEM If everything is in good order but the watercraft does not accelerate quickly when depressing the throttle lever and a good top speed cannot be ob tained the pump 15 probably ventilating then the ride shoe must be removed and resealed to the hull Refer to appropriate model year Shop Manual NOTE When resealing ride shoe ensure to elimi nate any possible flow restriction excessive seal er build up Use the silicone Ultra Black P N 293 800 028 which has the fastest curing time CAVITATION Cavitation can be defined as a phenomenon where the water inside t
107. l throttle The throttle plate is worth a closer look It s quite obvious that the throttle plate controls the entire operation of the carb At idle the throttle plate blocks off almost all air flow through the carb cre ating a very high amount of manifold pressure within the carb This high pressure is one reason that the low speed screw Is as sensitive as It Is small adjustments will make a big difference No tice that when the throttle plate is in the idle posi tion the bypass holes are actually above the throttle plate with the carb in the down draft po sition The bypass holes are actually having air drawn through them in this position It isn t until the throttle plate opens over the bypass holes that fuel actually passes through them www SeaDooManuals net SECTION 03 ENGINE PREPARATION Standard Needle Valve Size for Various Sea Doo Carburetors NEEDLE VALVE CARBURETOR MODEL SIZE 03 71 www SeaDooManuals net SECTION 03 ENGINE PREPARATION 5 6 7 8 I je m SS CE AL M gt G ZR HN 5 RSS 3 CSS SS CETERIS TY CN c ZZ TS 21 20 16 FO1F2CS 1 Low speed outlet 12 High speed screw 2 Bypass holes 13 Main jet 3 Throttle plate 14 Anti siphon valve 4 Fuel inlet 15 Pilot Jet I 16 Needle valve assembly 6 Check valves 17 R
108. lly lubricate PTO fly wheel and seal carrier if applicable with syn thetic grease P N 293 550 010 Stop greasing as soon as the first bit of grease comes out from under seals FO1IOBB 9 SEAL CARRIER OF DRIVE SYSTEM HX AND 5662 1 Grease fitting SECTION 04 PROPULSION SYSTEM Verify impeller shaft end play For racing pur poses maximum permissible end play new Is 0 12 0 54 mm 005 021 in Excessive play comes from worn protrusion end stop inside housing cover Excessive end play will nega tively affect performance Visually inspect protrusion end stop inside cover If worn small peak in center will be apparent O 1 NOTE On 1997 Sea Doo watercraft the cover has a pusher with a spring inside The purpose of the pusher is to reduce drivetrain noise Check pusher for wear The cover retrofits earlier models F01J1CA F00J09A 1 Pusher Lubricate drive shaft and impeller splines regu larly using synthetic grease The jet pump must be disassembled and drive shaft removed to perform this maintenance This is a good time to inspect spline condition of your drive shaft If excessive drive shaft wear is detected both PTO flywheel and impeller should be inspected 04 13 www SeaDooManuals net SECTION 05 MISCELLANEOUS TABLE OF CONTENTS EQUIVALENT WEIGHTS AND MEASURES CHART eee eene eene rennen nnn nnns 05 2 GLOSSARY OF TERMS IN PERSONAL
109. m 6 is still available From a functional point of view It is better to have the valve open a bit early than a bit late A18C02A Rave Valve Adjustment To adjust the RAVE valve turn the red adjustment knob all the way in clockwise Open the red knob 1 turn out counterclockwise and perform an ac celeration run on the craft starting from zero and accelerating to full soeed Repeat the procedure until you attain the best performance The use of a radar gun with acceleration recording capabili ties Is advised in order to obtain accurate data however rider observation will suffice SECTION 03 ENGINE PREPARATION Maintenance he RAVE components should be periodically checked The RAVE valve requires cleaning of car bon deposits Cleaning intervals would depend upon the user s riding style and the quality of the oil used Use FORMULA XP S synthetic injection oil and clean the valve periodically Check for clean passages between the exhaust port and dia phragm chamber If cleaning is necessary use sol vent to remove the deposits Also check the diaphragm for punctures replace if damaged No special solvents or cleaners are required when cleaning the valve Cylinder Boring Precaution In its stock configuration the RAVE valve guillotine has a minimum of 0 5 mm 020 in clearance to the cylinder bore measured at the center line of the cylinder This is the minimum production clearance There is only a first oversize
110. mbus tion will occur and lead to serious engine damage Detonation In detonation the spark plug initiates burning and the air fuel mixture starts to burn in the usual manner but as combustion continues the heat generated affects the large portion of the yet un burned air fuel mixture This unburned mixture temperature becomes so high that it burns spontaneously creating high velocity pressure waves within the combustion chamber Spark occurs as piston approches Top Dead Center F01D5GA SECTION 03 ENGINE PREPARATION heat and pressure rapidly build up 7 amp 2 Femaining unburned mixture burns spontaneously FO1D5LA These shock waves can sometimes be heard as pinging this pinging 15 especially detrimental to engines with raised compression ratios While these shock waves can be detrimental to the me chanical integrity of the engine it is the genera tion of excessive heat that causes most problems 2 stroke For many various reasons the piston may expand excessively causing a seizure or the piston dome may in fact melt The melting will oc cur at the hottest points which will be right below the spark plug and around the edge of the piston often at a ring locating pin If allowed to continue a hole may melt completely through the top of the piston 03 11 www SeaDooManuals net SECTION 03 ENGINE PREPARATION Pre ignition P
111. me your hold er will need to sign a release form 01 2 3 Required Safety Equipment A U S Coast Guard approved or Ill Personal Floatation Device PFD in sound condi tion must be worn by all competitors at all times when on the water A properly fitting full coverage helmet with chin and mouth protection face shield removed that meets current Department of Transportation or current Snell Foundation stan dards must be worn by all competitors at all times when on the water except during free style com petition All helmets must be in sound condition and must be approved at the technical inspection No plastic bicycle BMX or similarly designed headgear will be allowed Back protection protective footwear and eye pro tection are recommended but not required for riders in competition events You may also be required to have a dry chemical fire extinguisher in your pit area 4 Pit Area Setup At the race site you will be allowed to setup your pit area the morning of the event at approximately 6 00 a m Pit location is very important be there early You will have to place your watercraft close to the water line your equipment and tent if you have one must be placed little further away keep tidal fluctuations in mind The promoter may not be on hand during your setup Look the site over the night before if possible talk to the promoter to find out where to set up by doing this you will avoid movi
112. ment Distortion or out of round will impair the necessary free and smooth rotation Connecting Rod The connecting rod links the piston to the crank shaft Within each bored end of the rod is a needle bearing Rotax connecting rods are integral parts of the crankshaft assembly and therefore are not removable unless crankshaft is disassembled with special tooling If you are unsure about the condition of your crankshaft or if you know your crankshaft needs to be worked on it is highly sug gested that you send the crankshaft to a machine shop specializing in this type of work 4 Tl FO1D5TD 1 Connecting rod length www SeaDooManuals net Less expensive engines have the crankshaft and connecting rods mounted on sleeve bearings rather than roller or needle bearings The advan tage of roller or needle bearings is less friction and longer life Wrist Pin Provides support for the piston It also links the piston to the connecting rod This machined pin is inserted through a needle bearing resting within the upper end of connecting rod is supported by bosses and is locked in position with circlips ENGINE CONFIGURATION Two pistons are connected to a single crankshaft mounted in a horizontally split crankcase with 2 cylinders and a 1 piece cylinder head NOTE The 947 engine has a 1 piece cylinder block F01D6JA In operation while 1 piston is at TDC the other is
113. moter will discuss particular requirements for the day s events including practice order course layout starting procedures number of laps emer gency rescue technical inspections and award presentation If you have any questions or con cerns this is the time they should be discussed 7 Practice Practice is for the purpose of learning the course Red buoys signify left turns while yellow buoys are for right turns Be on the line ready to go when your class is called Do not race during practice You may injure yourself or damage your boat Many racers have been taken out during practice because of stupidity Don t join their ranks Re member learn the course don t tune your water craft during practice If your boat needs tuning it is due to poor preparation on your part Go to a des ignated free riding area so that you can devote your thought to tuning and not negotiating the course or another rider 8 Race and Result Posting The pit board will be posted before practice or shortly afterward Now is the time to make sure you have been placed in the correct class and that your boat number is listed correctly If you find any discrepancies see the Chief Scorer or Race Direc tor immediately Write down the race number that you are in note the designated number of finish ing boats that transfer to the final event All trans fer positions must report to tech inspection after the race If you do not transfer during your heat
114. n by hand using the long board sander his will help to indicate the low high spots along the hull surface Be care ful not to remove excess material FO5L01B TYPICAL 1 Shadow areas indicate possible high spots 2 Strakes 3 Corner to be reinforced www SeaDooManuals net d Using the dual action sander sand the low spots just enough to rough up the gelcoat These low spots are indicated where gelcoat hasn t been sanded with the long board This 15 done so that fairing compound will adhere e Measure the low area and mix up enough filler material to fill the area in Follow the manufac turers mixing instructions Fill low area and blend in evenly with bondo spreader Iry to leave your filler a little high so you have material to sand Allow proper curing time f Using the pneumatic long sander sand the area until you accomplish a flat surface Remember to finish edges radius and flat sections of strakes as well Using the straight edge check the area which was just finished Verify flatness and if the area still has a low spot start your filling steps again g At the rear of the watercraft where the tran som meets the hull there is a radius approxi mately 4 mm that should be covered with epoxy fairing compound and sanded to a square edge h For refinish we recommend using PPG prod ucts PPG high build K 36 primer can be used for fine finishing small hull irregularities after application
115. n fuel flow Pilot and main Jets are replaceable Different jet sizes are available to suit altitude and or tempera ture conditions Different jetting may be required as engine performance is increased Always inspect spark plug and piston dome color before selecting jetting options Spark plug or pis ton dome color is an indication of carburetion mix ture conditions Dark brown or black coloration indicates a rich condition while light tan or white indicates a lean condition Medium brown coloration may indicate a correct jetting range 03 77 www SeaDooManuals net SECTION 03 ENGINE PREPARATION li 1 Location to check spark plug coloration Refer to the appropriate Shop Manual of your wa tercraft for instructions on changing carburetor Jetting Main Jets for Mikuni Super BN Carburetors 2 0 500 318 03 78 Pilot Jets for Mikuni Super BN Carburetors PILOT JET SIZE PART NUMBER 270 500 201 270 500 180 270 500 164 270 500 117 370 500 165 270 500 175 270 500 166 270 500 149 270 500 167 If in doubt with carburetion jetting always begin with a rich setting and work toward a lean adjust ment NOTE It is recommended you always race with your fuel tank valve on the reserve position This should eliminate any possibility of air enter ing in the fuel system should the fuel tank level be lower than a quarter full RACING ENGINE PREPARATION SUMMARY NOTE Most machi
116. n plate using fasteners provided in the kit Use hoses provided in the kit and install them on the engine Install pump using reducer and appropriate tube s as necessary F01B2RA 587 ENGINE 1 Plug hose using a bolt and clamps FO1B2SA 587 ENGINE 1 Plug exhaust manifold drain hose with a pincher 2 Use 2 washers with exhaust manifold stud 03 39 www SeaDooManuals net SECTION 03 ENGINE PREPARATION F01B2TA FOIB2VA 657 ENGINE 717 ENGINE FRONT VIEW 1 Insert small hose inside large hole Secure with clamps 1 Loop hose and use clamps 2 Plug exhaust manifold drain hose with a pincher 2 Use 2 washers with exhaust manifold stud 3 Use 2 washers with exhaust manifold stud 3 Hose with adapter and nipple F01B2UB F01B2WA 717 ENGINE REAR VIEW 787 ENGINE 1 Engine drain hose blocked with a hose pincher 1 Loop hose and use clamps 2 Hose with clamps Plug end with a screw 3 Block engine drain hose with a hose pincher 4 Use 2 washers with exhaust manifold stud NOTE Water is not required for testing Activate pump and pressurize engine cooling sys tem to 34 kPa 5 PSI Wait 3 minutes and check if pressure drops if so verify all testing components If kit components are not leaking and pressure drops verify all external jointed surfaces tem perature sensor and the O ring between the spark plug area and the engine cylinder head cover If none of these components are leaking there is
117. n the fol lowing figure is the power curve of an engine with the RAVE valve held fully open through its entire RPM range Item 6 notes the peak power pro duced That peak will not change if the exhaust port time of a similar engine without a RAVE valve was the same with all other features equal Item 1 is the power curve of the engine with the RAVE valve closed through its entire RPM range The shaded area item 3 is the improvement in power at lower engine speeds that is gained be cause of the lower exhaust port If the port re mains at this height however the power would peak as noted in item 5 Raising the exhaust port at the proper RPM item 7 will allow the engine peak power to continue to rise item 6 www SeaDooManuals net Item P1 in the figure is the force of the return spring against the diaphragm The exhaust pres sure must be high enough to overcome this force before the valve begins opening Item P2 is the pressure required to completely open the RAVE valve Between P1 and P2 the usable power curve of the engine is moving from curve 1 to power curve 2 his transition takes place very rapidly at full throttle and from a practical stand point can be considered to be instantaneous at item 7 Gradual application of the throttle howev er will result in the RAVE valve opening much later If the RAVE valve opens toos late the engine will bog or hesitate momentarily as the RPM increas es Full peak performance ite
118. n travels to Top Dead Center and back to Bottom Dead Center once to complete the intake compression combustion and exhaust phases NOTE On all Sea Doo engines except the 947 the intake is controlled by a rotary valve On the 947 engine the intake is controlled by reed valves In the following illustrations the intake is controlled by the piston skirt Although these en gine configurations have their own characteris tics the basic engine theory remains the same The illustrations are provided to demonstrate the principles of operation of a 2 stroke engine 03 8 1 Intake and Secondary Compression Port Condition Intake port Partially opened Exhaust port Closed Transfer port Closed Boost port Closed When the piston starts its upward stroke a vacu um is created inside the crankcase and the air fuel mixture is sucked in from the carburetor via the intake port At the same time the piston blocks the exhaust and transfer ports and compresses the fuel charge in the combustion chamber sec ondary compression FO1D6FA 1 Exhaust 2 Compressed charge 3 Intake 4 Fresh charge 2 Ignition and Combustion Port Condition Intake port Opened Exhaust port Closed Transfer port Closed Boost port Closed As the piston approaches the top of the cylinder TDC the compressed air fuel mixture inside the combustion chamber is ignited by the spark plug The burning gases expand and push the piston downwa
119. nally the Race Director will be more open to your comments and in the future will place more validity on your side of the argu ment 01 10 SPONSORSHIP AND SOLICITATION There are many levels of sponsorship available to racers The amount of sponsorship you receive is primarily dependent on your national ranking and experience level novice expert pro There are many novice and expert racers with much greater sponsorship support than some pro racers The reason 15 that they made a commitment to their racing program They practiced hard stayed in shape and made sure their machines were al ways race ready Because of this they won races received media coverage and gained recognition Recognition is what sponsorship is all about Rac ers seek sponsorship to help offset the cost of racing while sponsors support you for one pur pose recognition of their product Your winning races promotes their products and exposes them to a large target population group The sponsor hopes this will enhance their image and sales As a novice expert or first year pro the type of sponsorship support you can expect will normally be very limited unless you re the best in your class When you re national number one sponsors will be at your door step however in the mean time you must actively seek support in every pos sible way Many large companies have solicited marketing specialists to research and determine the feasibility of racer sponso
120. ndicator CSI small stream of water flows out of bleed 7 y4 outlet located near 7 D stern eyelet Calibrated outlet fittings Engine water limit water outlet hose flow a pes j AY Water flows through tuned pipe and manifold water Jackets m Pressure zone Water flow regulator valve gt Lowest point of Water directly circuit allows Engine injected into muffler draining whenever Water inlet to cool exhaust engine is stopped hose of components hose valve FO1E1US 03 57 www SeaDooManuals net SECTION 03 ENGINE PREPARATION IGNITION SYSTEMS Two stroke engines in watercraft rely on an elec tric spark to initiate combustion of the air fuel charge which has been inducted into the combus tion chamber For the engine to operate efficient ly the spark must be delivered at precisely the right moment in relation to the position of the pis ton in the cylinder and the rotation at speed of the crankshaft Additionally the spark must be of suf ficient intensity to ignite the air fuel mixture even at high compression pressure and high RPM It is the function of the ignition system to gener ate this voltage and provide it to the spark plug at the correct time CDI System The Nippondenso Capacitor Discharge lgnition CDI system has 4 magnets located on the crank shaft flywheel AC voltage is induced in the gen erating coils as the pole
121. ng all your equipment later and you will be able to get a choice spot with easy access to the water as well as to your equipment You are also required to keep a fire extinguisher in your pit and store your fuel in a designated area www SeaDooManuals net SECTION 01 GENERAL RACING INFORMATION 5 Safety Inspection Before your watercraft is allowed on the water the Safety Inspector or his assistant must per form a safety inspection The Inspector will check your full face helmet and your personal flotation device for compliance with sanctioning requirements At that time your wa tercraft will be checked for safety requirements which are defined in your rule book and then affix a sticker to your watercraft which signifies your compliance After inspection you will be ready for practice but remember most promoters do not allow practice or free riding until after the rider s meeting Failure to comply can mean disqualifica tion or a fine During safety inspection ask the Inspector what type of fuel tests are going to be made if any Have your fuel tested at this time Fuel from filling stations sometimes have alcohol added and may not test legal Now is the time to find out and change fuel if necessary 6 Rider s Meeting The rider s meeting is mandatory for racers In many cases a roll call is held to ensure atten dance Failure to attend can be grounds for dis qualification or a fine During rider meetings the Pro
122. ng engine to the specified RPM FOOHOIA 1 Timing light straight in line with tool slot W CAUTION If engine is to be run more than a few sec onds engine must be cooled using the flush kit 4 Check if PTO flywheel mark aligns with timing tool slot NOTE On this system timing advance decreas es as engine speed increases If timing mark aligns with tool slot timing is prop erly set If not refer to Ignition Timing Adjust ment 03 62 787 787X and 947 Engines 1 Connect an induction type tachometer P N 295 000 100 to spark plug wire S F06H06A 1 Tachometer pick up 2 Connect timing light pick up to MAG side spark plug wire FOOHOHA 1 Timing light pick up 3 Rev the engine to 3500 RPM and point beam of timing light straight in line with timing mark pointer www SeaDooManuals net F06H07A 1 Timing light straight in line with tool slot W CAUTION If engine is to be run more than a few sec onds engine must be cooled using the flush kit NOTE If mark on PTO flywheel is perfectly aligned with timing mark pointer no adjustment Is required If it is not the case refer to Ignition Timing Adjustment Ignition Timing Adjustment 587 657 657X 717D and 717 Engines Remove battery if applicable Remove magneto housing cover and wire support Remove magneto flywheel Timing is performed by moving armature plate clockwise to retard spark occurrence or counter
123. ning and or grinding is illegal in limited class racing Keep your watercraft legal check the rules 1 Remove and disassemble the engine according to appropriate model year Shop Manual proce dures 2 With the crankshaft resting in the lower half of the crankcase set up a dial indicator and check the runout of the crankshaft at both ends You should see no more than 0 05 mm 002 runout If you have the capability adjust the crankshaft as close to perfect as possible www SeaDooManuals net Most machining or grinding is illegal in the Limited Class Ports or cylinder liners may not be modified in any way In the Superstock Class base gaskets and head gasket surfaces of the cylinder may be machined a maximum of 1 00 mm 040 inches Port widths heights and shapes may be altered but no ports may be added or deleted Aftermarket cylinder liners may be used KEEP YOUR WATER CRAFT LEGAL CHECK THE RULE BOOK T n J NIL Y lt gt Cisco E F01D1TA 1 Measuring MAG side deflection in crankcase 3 Set your cylinder base gaskets and cylinders on the upper half of the crankcase and lightly torque the cylinders to the case half Be sure to install exhaust manifold on the cylinders before tightening them to the upper crankcase half to ensure the same position of the cylinders on final assembly Check the match of the gaskets and cylinders to the base match them perfectly with a die grinder in
124. nkshaft deflection is measured at each end with a dial indicator First check deflection with crankshaft in crank case f deflection exceeds the specified toler ance It can be either ball bearing wear bent or twisted crankshaft at connecting rod journal F01D1SA 1 Measuring PTO side deflection in crankcase www SeaDooManuals net SECTION 03 ENGINE PREPARATION Connecting Rod Big End Axial Play Using a feeler gauge measure distance between thrust washer and crankshaft counterweight F01D1TA 1 Measuring MAG side deflection in crankcase Remove crankshaft bearings and check deflection again on V shaped blocks as illustrated FO1D1WA 1 Measuring big end axial play 2 Feeler gauge At Assembly Pay particular attention to the following Bearing Apply Loctite 767 anti seize lubricant P N 293 550 001 on bearing seats Prior to installation place bearings into a container filled with oil previously heated to 75 C 167 F This will expand bearings and ease installation Crankshaft with a Labyrinth Sleeve To properly locate outer PTO bearing install laby rinth sleeve against inner bearing side 2 0 F01DAUA FO1D1VA 1 Measuring PTO side deflection on V shaped blocks NOTE Crankshaft deflection can not be accurately measured between centers of a lathe 3 O ring 03 47 www SeaDooManuals net SECTION 03 ENGINE PREPARATION NOTE Be sure to i
125. nsition circuit change the pilot jet or pop off pressure If a slight lean or rich condition exists while accelerating from just off idle to half throttle change the pilot jet Increasing the Jet size will richen the mixture Make any jet changes in small increments of jet sizes If a se verely lean or rich condition exists in transition it will be necessary to readjust the pop off pressure Refer to the pop off chart to determine how to change components for pop off adjustment NOTE To accurately check and adjust pop off pressure it will be necessary to use a pump gauge tester P N 295 000 114 which is available through your dealer The pop off chart in this sec tion is for approximating pressure only SECTION 03 ENGINE PREPARATION High Speed Screw High speed screw adjusts the air fuel mixture in conjunction with the main jet for maximum full throttle performance The initial setting for the high speed screw is closed If you are uncertain that this setting will provide enough fuel do not hesitate to start with the screw out more turns Turning the screw clockwise inward will lean the mixture counterclockwise will richen the mixture The high speed screw is effective up to 3 full turns out The plastic cap must be removed for adjustments over 1 4 turn Manifold Pressure Manifold pressure is the suction generated by the engine against a restriction the strength of this suction is measured in inches of mercury In t
126. nstall labyrinth sleeve with its hollow side facing PTO side outer bearing FO1D4VA 1 PTO side outer bearing 2 Hollow side slide on outer bearing until it touches sleeve Install bearings so that their peripherical grooves will be located as shown in the following illustra tion F01D1ZA 1 Peripherical grooves on inner side if applicable 2 Peripherical grooves on inner side NOTE Not all engines are equipped with the lab yrinth sleeve between the PTO crankshaft bear ings For racing purposes it would be advantageous for engines with dual carburetors to have the laby rinth sleeve installed except the 787 and 947 en gines to help displace crankcase volume thus Increasing primary compression ENGINE BREAK IN PROCEDURE When preparing an engine for racing many de tails must be made exactly to specification to achieve the maximum performance 03 48 To obtain the most benefit from your labor and money a proper break in is essential The proper break in procedure allows all of the rough metallic surfaces to slowly begin to Tit each other resulting in minimum friction loss and maximum power output The importance of this procedure should not be underestimated With Bombardier Rotax watercraft engines a break in period is required before operating the engine at full throttle Engine manufacturer rec ommendation is about 10 operating hours During this period maximum throttle should n
127. nt in the dots which now can be easily read At some races the inspector will place a special sticker with a serial number on the rear of the hull for eas ler reading www SeaDooManuals net SECTION 01 GENERAL RACING INFORMATION After your hull number is recorded the inspector may make a series of visual inspections inside and outside the hull to verify class legality or to see if safety requirements have been met The inspec tor may use a paint type seal on various areas of the engine to prevent a rider from going into the engine and removing illegal parts that may have been used for qualifying If after the race some thing goes wrong which requires you to break a seal to perform service take your boat to the in spector before breaking the seal You will then be able to perform repairs at tech This will allow the inspector to check the parts coming out for legal and he will be able to apply a new seal upon completion After your final moto you will then return to tech for verification of hull and seal authenticity At this time the inspector may require the top 3 finishers to disassemble various parts of the engine for close inspection You and one mechanic will be allowed in tech to disassemble the required items You will not be reimbursed for any cost of gaskets etc If you refuse tear down you will be disqualified In limited classes usually the techni cal inspector has you remove the rotary valve housing in or
128. ntake manifold intake manifold O ring flame arrester and housing throttle cable and other hardware must be changed Also a laby rinth sleeve should be installed on the crank shaft PTO side The carburetor from a single type set up cannot be used in a dual carburetor application 7 Check the match of mating surfaces through out entire engine exhaust system Smooth or blend in any mismatched mating surfaces if al lowed by your racing association rules 8 he engine should be pressure tested for leak age 9 Adjust ignition timing to the recommended ad vance Before Top Dead Center All 1992 and up engines except the XP 5852 5854 and engines equipped with a DC CDI system are equipped with a single magneto coil and may need to be changed to either the 1991 ignition or XP 5852 5854 dual magneto coil ignition If the engine maximum RPM has been increased due to im peller changes it would be advantageous to use the dual magneto coil because the advance curve of the ignition will be better suited to the higher RPM Ensure that the rev limiter is prop erly calibrated for the RPM range you wish to operate your engine When choosing a peak op erating RPM it is very important to avoid oper ating an engine at certain RPM s for extended periods For the 587 engine 6800 RPM is the maximum harmonic imbalance and 7400 RPM for the 657 type If the engines are run con stantly at these RPM s serious engine damage may occur The 787 and
129. o appropriate model year Shop Manual for proper removal and installation proce dures MEASURING THE HULL A straight edge should be used to measure the condition of the hull bottom surface Place straight edge on its most rigid side along the bot tom of the hull Identify the low and high spots on the surface as shown below 1 Place straight edge at different locations as shown by shadow areas 2 Not necessary to true beyond this point 02 2 TRUING THE HULL Truing the hull means to make the hull as straight as possible This will help you gain maximum per formance and top speed Follow these steps and you will produce a good racing hull Special tools and materials may be required to perform this work Required Tools and Materials pneumatic long sander long flat sander long board dual action sander sandpaper epoxy fairing compound found at marine sup ply store filler spreader long straight edge NOTE It is not recommended to use bondo or auto body filler as it is less durable and can absorb water A compound with fiberglass particles in it will be very hard to sand flat and true if proper techniques are not observed Procedure a Remove intake grate b Mask off body and ride plate Accurately place masking tape down in seam where ride plate meets relief in hull c Carefully sand each sectio
130. of fairing compound PAINTING General The following was prepared in conjunction with PPG Industries Inc It contains 2 painting proce dures the most commonly used and DELTA with low VOC mainly used in Cali fornia If more information is needed contact a PPG deal er or a Sea Doo watercraft authorized dealer CONCEPT PAINTING PROCEDURE For additional information refer to PPG P Bulletin no 168 Surface Preparation Prepare and clean surface consistent with good painting practices Primer DP Epoxy Primer DP 401 Catalyst DX 1791 1792 prime before topcoating SECTION 02 HULL PREPARATION Primer Surfacer K36 K201 K200 K201 or DZ KONDAR Primer Surfacers NOTE KONDAR must be sealed before apply ing CONCEPT color Sealer KTS30 2K Sealer DP Epoxy Primer reduced as a sealer or DAS 1980 or DAS 1987 Direct Gloss Color How to Mix standard Air Dry Mix CONCEPT Color 2 1 1 2 parts color with 1 part DI Reducer best suited to shop temperatures and 1 part DU 4 below 29 C 85 F or DU 5 above 29 C 85 F Hardener Standard Force Dry Mix CONCEPT Color 2 1 1 Application temperatures below 29 C 85 F use DU 5 Hardener above 29 C 85 F use DU 6 Medium Solids MS Application For faster film build when using solid colors mix 2 parts CON CEPT color with half part DI Reducer and 1 part DU 5 or DU 6 Hardener Select the DT Reducer appropriate for shop tem
131. omponents E as F01D70A 1 High speed screw 2 Fuel return 3 Fuel inlet 4 Pulse nipple 5 Outer venturi 6 Inner venturi 7 Fuel pump assembly 8 ldle stop screw 9 Low speed screw 10 Regulator diaphragm high and low speed jets needle valve assembly Internal Components At first look the cutaway drawing see next page appears somewhat straight forward but some in teresting things appear as you study it Follow the fuel flow through the low speed circuit Fuel flows through the low speed jet and then is divided with part of the fuel being metered by the low speed screw An additional route the low speed fuel takes is through the by pass holes transition circuit Fuel is drawn through the by pass holes as the throttle is opened and the butterfly valve exposes them to the air flow The ability for fuel to pass through the low speed circuit and its transi tion is controlled first by pop off pressure then by the size of the low speed jet NOTE If the low speed jet size is changed it af fects the mixture both at idle speed and off idle 03 69 www SeaDooManuals net SECTION 03 ENGINE PREPARATION Viewing the high speed circuit notice that fuel is divided at the high speed jet so that even if the high speed screw was fully closed fuel would still pass through the jet The fuel flow chart illustrates the adjustability of total fuel flow with the high speed screw It is possible with the Super BN to
132. on being the IJSBA The sanctioning body requires the promoter to meet safety standards and provide adequate insurance coverage for the event You should purchase a rule book from them or join the sanctioning body and receive a free rule book well before you go racing Study the rule book learn the procedures and require ments The rule book will give you strict guide lines as to what is allowed to be done to your watercraft for racing within a particular class You can not make modifications that are not specifical ly outlined in the rule book Keep a copy of the rule book in your tool box for reference The phone number and address of the IJSBA is on page VI of this manual Call or write and they will send you an entry form You must however be 15 years old to join If you are under 18 you must request a parental release form that must be signed and notarized by your parent or guardian Entry forms for every race must be signed by your parent or guardian 2 Registration Registration for a race should be done by mail sev eral weeks before the event This is the procedure preferred by the race promoter However most promoters not all will also hold late registration the night before or the morning of the race Those who choose late registration are charged a penal ty fee for that privilege During registration you will have to indicate on the entry form the type of event and classes you have chosen to enter Also at that ti
133. on to your boat while you increase the throttle Holders must be synchronized with you and the Starter Many races are won or lost by your holders ability to get you off to a good start Holders must use gloves to do a good job www SeaDooManuals net SECTION 01 GENERAL RACING INFORMATION Starting procedures at your event will be dis cussed during the riders meeting However the best way to get the edge is for you and your hold ers to watch the Flag Man and Starter on the rac es prior to yours Watching them will allow you to see the rhythm or pattern they are using for the start his can give you the edge It is very important to remember that if you jump the start you will be severely penalized You will have to start with a dead engine your teather in your hand and only 1 holder or no holder to keep you In position While the 72 card is being displayed by the start er the rider has the opportunity to call a 2 minute hold in the event they are experiencing difficul ties on the starting line for example a sparkplug fouling or the inability to get the engine started At this point the starter will allow the rider 2 minutes to correct the problem Once the 1 card is dis played a 72 minute hold can not be called When the 1 card is turned sideways the race will be gin within 0 5 seconds when the rubber band 15 released Only one 2 minute hold is allowed per start 11 Racing Upon the start hold your line
134. opriate model year Shop Manual 03 60 www SeaDooManuals net 7 Scribe a thin mark on PTO flywheel in the mid dle of tool slot 587 657 657X 717D and 717 engines or aligned with timing mark pointer tool 787 787X and 947 engines FO1H5SB TYPICAL 1 Tool slot 2 Flywheel mark NOTE This mark becomes the reference when using the stroboscopic timing light W CAUTION The static test cannot be used as a timing procedure therefore always check the tim ing with a stroboscopic timing light 8 Remove TDC gauge 9 Reinstall spark plug and connect wire Dynamic Test To check ignition timing use Bombardier timing light P N 529 031 900 SECTION 03 ENGINE PREPARATION 587 657 657 7170 and 717 Engines NOTE To perform this procedure make sure to use a stroboscopic timing light rated up to 6000 RPM Otherwise an inaccurate reading will be ob tained The ignition components are affected by temper ature variation therefore timing must be checked when engine is cold after idling for a MAXIMUM of 20 seconds 1 Connect an induction type tachometer P N 295 000 100 to spark plug wire FOOHOGA 1 1 Tachometer pick up 2 Connect timing light pick up to MAG side spark plug wire 03 61 www SeaDooManuals net SECTION 03 ENGINE PREPARATION FOOHOHA 1 Timing light pick up 3 Start engine and point timing light straight in line with timing tool slot Bri
135. ot exceed 3 4 however brief full acceleration and speed variations contribute to a good break in Continued wide open throttle accelerations pro longed cruising speeds and overloading the en gine are detrimental during the break in period assure additional protection during the initial engine break in 250 mL of SEA DOO INJECTION OIL should be added in the fuel tank for the first full fuel tank filling only NOTE Replace spark plugs after engine break in RECOMMENDED OIL All Sea Doo watercraft can use BOMBARDIER ROTAX INJECTION OIL P N 413 802 900 1 L or 413 803 000 4 L which is available from autho rized dealers It is a blend of specially selected base oils and additives which provides outstand ing lubrication engine cleanliness and minimum spark plug fouling For the ultimate engine protection BOMBARDIER ROTAX Formula XP S P N 413 710 500 1 L or 413 711 000 4 L can also be used This fully syn thetic oil provide outstanding cleanliness less friction and wear for greater engine performance and durability NOTE High quality low ash API TC injection oil for 2 cycle engines can be used if BOMBARDIER ROTAX INJECTION OIL is not available W CAUTION Never use 4 cycle motor oil and never mix with outboard oil Do not use NMMA TC W TC W2 or TC W3 outboard oils or other ash less type 2 cycle oils Avoid mixing different brands of API TC oil as resulting chemical re action may cause severe engine dama
136. otary valve 3 Gear crankshaft 4 Gear on rotary valve shaft Advantages of the Rotary Valve Engine The major differences between a piston port en gine and a rotary valve engine are 1 Intake port directly positioned in the crankcase 2 The opening and closing of the intake port is controlled by a rotary valve instead of the pis ton allowing asymmetrical timing The use of a rotary valve enables a very short inlet track The design introduces the mixture in a very suitable position without obstruction to the gas flow that would impair the volumetric efficiency This intake position also enhances the lubrication of the lower connecting rod bearings With rotary valves the opening duration of the intake port is specifically controlled by the valve Therefore it is possible to determine the maximum possible in take with benefit to crankcase filling The following chart indicates the intake phase dif ferences between a piston port engine and a rota ry valve engine PISTON PORT ROTARY VALVE INTAKE ENGINE ENGINE Total 5 03 21 Opening BTDC Closing ATDC www SeaDooManuals net SECTION 03 ENGINE PREPARATION As shown for the rotary valve engine the total du ration of the intake is greater and the opening starts earlier This results in a better volumetric ef ficiency In the rotary valve engine the intake closes earlier to avoid fresh charge spitback With the rotary valve duration of the
137. out 750 PSI takes place at about 15 after crankshaft rotation ATDC Normal combus tion is the controlled burning of the air fuel mix ture in the cylinder The flame is initiated at the spark plug and spreads to the unburned at the edges of the cylinder The flame front travels through the cylinder at about 30 m 100 ft per second In order to achieve maximum pressure at about 15 ATDC the spark must occur about 15 BTDC Complete combustion will finish at about 35 ATDC The actual amount of spark advance BTDC is depen dent upon bore size combustion chamber shape operating RPM mixture turbulence and the actual flame speed Flame speed is directly proportional to piston speed in an almost linear fashion Though it is not completely understood why this relationship ex ists itis thought to be related to intake speed and mixture turbulence Hence flame speed increas es as RPM increases It also increases as the fuel ratio becomes leaner Because the flame speed is slower at lower RPM s more advance at low RPM is necessary for maximum performance Advancing the spark too much BTDC for the needs of the engine will cause the engine to detonate Ignition advance on Rotax engines is measured by a linear distance of piston travel BTDC A dimen sion taken through a straight spark plug hole in the center of the head is a direct measurement A di rect measurement can be converted to degrees of crankshaft rotation by the ap
138. out just like you with the ambition to be the very best racer they could be With hard work preparation and a little luck you can do the same THE PROFESSIONALS POINT OF VIEW Westcoast Performance Products Racing Team Manager Tim Norton was asked what does a Team Manager look for in the Ideal Racer This was his response When analyzing talent Team Managers in today s motorsports world look at many attributes of a po tential candidate Because of those attributes the decision making process can be complicated to score an overall picture of a rider s talents There are times when you have to look at all of the attributes and compare them to your specific needs in a rider and there are times when you just go with your gut feeling view talent as an au tomatic criteria You must have it before we even look No talent no consideration So assuming your past that stage we next turn to another key item which is attitude 01 11 www SeaDooManuals net SECTION 01 GENERAL RACING INFORMATION The right attitude can propel talent to the next lev el or stop it dead in it s tracks We like riders who view every test as a challenge and every race as a new goal to strive for Our riders are never larger than the support staff and by acting that way always win the admiration of the race team crew A successful rider with the right attitude can convince his her crew to go into battle with them every time his
139. ove and reinstall the engine again otatic bench testing is the most effective way to conduct a leakage test Inboard testing does not allow complete access to and observation of all engine surfaces and should be avoided whenever possible On some twin cylinder engines cylinders can not be verified individually due to leakage from one cylinder to another through a common intake manifold When installing hoses of the Engine Leak Test Kit use the collars provided in the kit to ensure a prop er sealing When pressurizing the engine first confirm that the components of the Engine Leak Test Kit are not leaking by spraying a solution of soapy water on all hoses connections fittings plates etc If there is a leak bubbles will indicate leak location Three areas of the engine will be tested in se quence as per the diagnostic flow chart on page 03 38 1 Engine Cooling System 2 Bottom End and Top End 3 Rotary Valve Shaft NOTE If a leak is found it is important to contin ue testing as there is the possibility of having more than one leak Continue pumping to com pensate for the air lost to find another leak SECTION 03 ENGINE PREPARATION Bench Testing Procedure Engine Cooling System Remove the exhaust manifold gasket and ensure the surface is cleaned Install the appropriate exhaust manifold plate no 1 for the 787 engine and no 2 for other en gines except the 947 from the Engine Leak Test Kit Tighte
140. perature Pot Life Pot Life of ready to spray CONCEPT color is 6 to 8 hours at 21 C 70 F Medium solids option is 2 to 4 hours at 21 C 70 F Full Panel and Overall Repairs Application Apply 1 medium wet coat and give 5 10 minutes flash followed by 2 wet coats with 15 minutes flash time between each coat Adjust metallic on the last full wet coat If necessary apply a mist coat For medium solids option apply 2 full wet coats Air Pressure 275 345 kPa 40 50 PSI at the gun Dry Time dust free 30 minutes tack free 2 to 3 hours tape print free 6 hours dry to handle 6 to 8 hours at 21 C 70 F force dry 40 minutes at 60 140 F Faster dry times may be obtained by using 15 mL 1 2 oz of DXR 81 Accelerator per sprayable 1 2 L quart however the pot life is reduced to 2 hours 02 3 www SeaDooManuals net SECTION 02 HULL PREPARATION Spot Panel Repairs Application opray medium wet coat of color on the repair area and allow 5 10 minutes flash time Apply 2 additional full coats until hiding is achieved extending each coat beyond the previous coat Flash 15 minutes be tween each coat For medium solids option apply 2 full wet coats Blending Add DT 95 Reducer to a second gun cup Reduce the fluid feed of the gun and lower the air pressure to 207 kPa 30 PSI Dust the dry edge until a slight wet look appears then stop Or mix reduced and catalyzed color with equal parts of reduced
141. propriate formulas Initial ignition timing procedures can be found in the appropriate model year Shop Manual When working with modified engines it may be necessary to alter ignition timing from stock spec ifications to achieve maximum power output or to prevent engine damage select a fuel that meets the octane requirement for the compression ratio of your engine REFER TO OCTANE REQUIREMENTS FOR ROTAX EN GINES Once you have chosen the fuel you will be tuning the engine IGNITION TIMING for max imum efficiency for that fuel If you change to an other brand of fuel or a different octane it will be necessary to re tune the engine Failure to do so may cause engine damage or power loss www SeaDooManuals net NOTE For initial tuning it is recommended that you test using 1 heat range colder spark plug than stock If upon completion of tuning the center in sulator shows excessive carbon deposits go back to the stock heat range spark plug If you have increased the engine compression the fuel mixture will normally burn at a faster rate Because of this effect combustion chamber pres sure may peak sooner than desired If this occurs the engine will overheat leading to detonation and extreme engine damage Because of these possi bilities it is recommended that you pay particular attention to your spark plug readings during your initial tuning If there are any signs of overheating or if detonation is heard it is advisable to
142. r have gone outside the finish line buoy during the race or at the finish only to be penalized one lap Racers with big leads have ac tually come to the finish line slowed down and turned directly into the technical inspection area without crossing the finish line Others have been passed because they slowed down Race past the finish line continue around the course as not to interfere with slower riders still finishing the race Never turn and go against the flow of traffic after you have finished the race even if you are going to tech Continue around the course to get back 12 Technical Inspection After your qualifying race or moto you will be re quired to go to Technical Inspection if you have placed in a transfer position On your first trip to tech the Technical Inspector will record your hull number The hull number is located below the bond flange on the right rear of the hull The pur pose of recording your hull number is to insure that you will be running the same boat in the final that you have qualified for or in your second moto On a Sea Doo the number is imprinted in the fi berglass or on a black tag with a series of dots forming letters and numbers This number can be extremely hard to read especially in the water To make reading easier paint over the numbers with white paint After the paint dries lightly use steel wool or very fine sandpaper to take the paint off of the hull This procedure will leave the pai
143. race boat is fired up Remember this is a team effort Next a successful rider always has inner drive This is required to push through those tough times A DNF a lapped rider or a bad start can break even the strongest spirit but having a strong will to perceiver and overcome is needed to rebound in the event that luck isn t always look Ing your way Additionally focus is also a key We look for riders who have started at a given point and attacked the class at hand They continually improve until they become champion and then move on to the next goal regardless of what level they start at Finally once you have shown you have the above mentioned skills we look at your people skills We definitely want riders who genuinely like to be around other people he team is in the promo tions business and a major part of being a team rider is the ability to impress people on and off the track Being a factory team rider is not for everyone But If you have what it takes in the above men tioned areas you will be seriously considered to be a team rider Tim Norton Team Manager Westcoast Performance Racing Chris Fischetti and Kelly Kurpil are two of the top Professional Sea Doo racers in the world Each were asked to give their point of view concerning their racing careers Header Chris Fischetti Being a Professional Racer is unlike any other oc cupation Your job is not 8 to 5 with weekends off itis a total f
144. rce dry before sanding or taping 02 4 www SeaDooManuals net SECTION 02 HULL PREPARATION SEA DOO PAINT CODES B 176 si 176 VIPER RED 74790 M 506 BRIGHT YELLOW BODY METALICFORESTGREEN 65 MARINE GREEN ne wemucsug Dwem BRIGHT METALLICPURALE 585 wwmEnseney e SSO 8607 WHITE 092 e 5801 88 01 WHITE 1993 1994 923 2935004 5801 88 01 SUPER WHITE 1995 1997 98260 293500082 5801 88 02 YELLOW 1988 1989 88207 293500008 essem muc J _ sean 285005 2935069 RUE 5898 692 2989002 okay __ 290 500 000 seas 200 500 067 5069302 tos 2800066 5109002 MEDUMGRAY 32 850009 rserzazo1 MAGENTA s se 2935060929 562950 ee 5509 5852 93 01 GREEN STORAGE COVER 49500 essor Rune _ 5870 94 01 TEAL STORAGE COVER 1893 293500068 5870 94 02 RHODAMINE 7824 293500083 02 5 www SeaDooManuals net SECTION 02 HULL PREPARATION STORAGE COVER PAIN
145. rd thus causing a power stroke www SeaDooManuals net F01D6GA Exhaust Combustion Intake Fresh charge N 3 Exhaust and Primary Compression Port Condition Intake port Closed Exhaust port Partially opened Transfer port Closed Boost port Closed As the piston descends the intake port is blocked and pressure begins to build inside the crankcase primary compression As the piston continues Its course downward the exhaust port is uncov ered and burnt gases are allowed to escape SECTION 03 ENGINE PREPARATION F01D6HA Exhaust Burnt gases Intake Fresh charge 4 Transfer Port Condition Intake port Closed Exhaust port Opened Transfer port Opened Boost port Opened Near the bottom of the downward stroke the transfer port is uncovered and the compressed air fuel mixture inside the crankcase rushes into the cylinder and combustion chamber Just after the opening of the transfer port the boost port opens and this allows the remaining air fuel mix ture mixture trapped under piston crown to flow into the combustion chamber This assists in clearing the combustion chamber and cylinder of all burnt gases The boost port also aids in cooling the piston dome lubricating and cooling wrist pin bearing The cylinder head transter port and exhaust pipe design limit the escape of the fresh incoming charge to a minimum www SeaDooManuals net SECTION 03 ENGINE
146. re competing in a multi day event the inspection will be valid for the entire event PRERACE MAINTENANCE The following items should always be checked when preparing for an upcoming race 1 Check the engine compression If the com pression is low or the variance between cylin ders is greater than 10 PSI determine the cause and remedy the problem Check the torque on the cylinder head bolts with a torque wrench using the proper tightening pattern Put in new spark plugs 2 Check the ignition timing and ignition flywheel nut torque 3 Lubricate the electric starter gear and shaft Check the starter mounting bolts for tightness and the starter electrical cable for a clean cor rosion free connection both on the starter and solenoid www SeaDooManuals net SECTION 01 GENERAL RACING INFORMATION 4 Check all rotary valve housing intake mani fold and carburetor mounting bolts for tight ness 5 Check for correct oil injection pump adjust ment if an injection pump is being used 6 Check the fuel filter for debris or water if any abnormality is noticed remove and clean the fuel tank fuel filter fuel lines and carburetors 7 Carburetor diaphragm screws should be checked and pop off pressure verified Now is a good time to check your low and high speed fuel mixture screws to make sure they have not backed out and are still set to the required setting Throttle cable operation should be checked to insure max
147. re ignition is the ignition of the mixture inside the combustion chamber before the timed spark Pre Ignition sources are generally an overheated spark plug tip or a glowing carbon deposit on the piston head Since ignition occurs earlier than the timed spark the hot gases stay longer in the combus tion chamber thus increasing cylinder head and piston temperatures to a dangerous level i E Portion of the mixture is ignited by a hot spot before timed spark occurs F01D5MA NOTE Detonation and pre ignition are conditions you need to be listening for as serious engine damage or complete failure may occur if this con dition is allowed to continue These 2 conditions can be heard if you are listening carefully The en gine will produce a sound similar to glass bottles rattling together or a noise which sounds like transmission gears growling These sounds will usually be more audible at specific throttle posi tions Do not hold the throttle at these positions for any longer than absolutely necessary just the amount of time required to identify verify that there is a problem 03 12 il timed spark occurs ij Hame front spreads and collides with pre ignited portion of mixture IS E F01D50A i until all mixture is burned F01D5PA www SeaDooManuals net SECTION 03 ENGINE PREPARATION Usually the pi
148. rough cover inlet ports to verify clearance At least verify clearance at 2 different places in each port www SeaDooManuals net F01D53A 1 45 feeler gauge If rotary valve cover clearance is out of specifica tion machine rotary valve cover seating surface or replace the cover Solder Method Remove O ring from rotary valve cover Use the following type of solder osin core diameter 0 8 mm 032 in electronic application available at electronic stores Install 2 solder pieces of 13 mm 1 2 in long di rectly on rotary valve one above and one below rotary valve gear Apply grease to hold solder in position Reinstall cover in place WITHOUT its O ring and torque screws to 20 Nem 15 Ibfeft Remove cover then clean and measure compressed solder thickness it must be within the specified tol erance 0 30 0 05 mm 012 002 in SECTION 03 ENGINE PREPARATION TYPICAL 1 Solder If rotary valve cover clearance is out of specifica tion machine rotary valve cover seating surface or replace the cover Machining Information The amount of material over tolerance must be removed from the rotary valve cover seating sur face Also cut the O ring groove the same amount to keep the 1 0 0 03 mm 039 001 in depth be tween the bottom of the groove and the seating surface Remove burrs on the edges of the seating surface and O ring groove 03 23 www SeaDooManuals net SECTION 03
149. rship while most smaller or local businesses have not On a region al level these smaller businesses may not even realize the potential for product recognition that watercraft racing can bring them Go after these sponsors invite them to a regional race so that they can experience first hand the advertising op portunities available to them When making initial contact with a potential spon sor attempt to set up an appointment to meet with them Iry to avoid discussing your proposal over the phone or by mail Face to face meetings normally accomplish much more Major sponsors will have representatives at the national events in your area Call these people several weeks prior to the event and arrange a meeting with them dur ing race weekend In many instances personal meetings are impossible When this is the case contact the sponsor by phone and inform them that you will be sending your resume and spon sorship proposal to them for review Close your conversation by setting a date to call again to dis cuss your proposal www SeaDooManuals net SECTION 01 GENERAL RACING INFORMATION Your resume should begin with your personal in formation such as name age address marital status schooling completed occupation etc Next you should list your future goals as a water craft racer This section should be concise and to the point It should outline your short term and long term goals After your statement of goals list all t
150. s accel eration is very important where in an off shore race top speed is a priority www SeaDooManuals net SECTION 04 PROPULSION SYSTEM TABLE OF CONTENTS BASICFUNCTIONS OF THE NUM IP n UEM DIR OU 04 2 PROPULSION SYSTEM ANALYSIS ecce rere erneuern nnne tnn unt nn 04 2 PAS RIS pen Ei di u s 04 3 euge cm e 04 4 IPL DPP 04 4 IMPELLER APPLICATION CHART p 04 7 IMPELLER SPECIFICATIONS AND BOOT APPLICATIONS 04 9 IMPELLER PITCHGHART u u AAA EA ass 04 10 ENGINE JET PUMP ALIGNMENT uuu aa um E 04 11 FUNCTIONS OF THE VARIABLE TRIM SYSTEM VTS 04 12 PROPULSION SYSTEM MAINTENA NGQGE eee ee rennen enne nn nnn nnn nennen nnn nnne 04 13 04 1 www SeaDooManuals net SECTION 04 PROPULSION SYSTEM BASIC FUNCTIONS OF THE SYSTEM The following is a brief explanation of some of the principals behind a water jet drive system As the impeller begins to turn with the rotation of the engine it will move a volume of water through the pump housing into the venturi section or venturi As the volume of water is forced through the smaller cross section it will be accelerated in flow thus creating thrust or forward propulsion However the volume in and volume
151. s of the magnets rotate past the poles of the coils Timing is controlled by the position of the coil poles relative to the mag net poles which are directly related to piston po sition The CDI module contains the electronic circuitry to store and control the initial voltage and deliver it to the ignition coil and then the spark plug at the correct moment The ignition coil is a transformer that steps up the relatively low volt age 150 300 V of the generating coil to the 20 000 40 000 volts necessary to jump the spark plug gap and initiate the burning of the air fuel mixture in the combustion chamber NOTE On several models the CDI module is in tegrated in the ignition coll DC CDI System The Nippondenso Direct Current Capacitor Dis charge Ignition system offers a more powerful and stable ignition at low 5 The magneto is responsible for charging the bat tery which is the primary source for this system A trigger coil is mounted outside the rotor inside the magneto housing of the engine and is not ad justable Its purpose is to signal the engine posi tion to the MPEM The rotor has 2 protusions 180 apart that when coupled with the trigger coil accomplish the signaling The ignition coil steps up the voltage input from the MPEM to high voltage current for the spark plugs 03 58 All Systems Maximum power from a given engine configura tion Is produced when peak combustion chamber pressure ab
152. s onto sponson studs using a flexible 4 claw pick up tool Snap on YA837 Ap ply Loctite 242 to nuts prior to installation 02 9 www SeaDooManuals net SECTION 02 HULL PREPARATION F01P09A Install lock nuts by using the 4 claw pick up tool or a 10 mm deep socket lorque nuts to 14 Nem 10 Ibfeft Urethane Foam Reinstallation When sponsons installation is completed you can reinstall the first removed urethane foam core into each hole Glue with 732 multi purpose seal ant P N 293 800 006 02 10 www SeaDooManuals net SECTION 03 ENGINE PREPARATION TABLE OF CONTENTS ENGINE TUNING CAUTIONS C 03 2 BASIC ENGINE Ee VV WIN osc grea czy c 03 2 BASIC ENGINE COMPONENTS aus ___ _____ qaqaq 03 3 ENGINE CONFIGURATION I 03 7 BASIC ENGINE uu 03 8 CONBJSTION PROCES 1 5 u uuu ss m ns Mm 03 10 SOLD SPLA E sms 03 13 COMBUSTION CHAMBER VOLUME 03 14 CALCULATING THE COMPRESSION RAIIO U nM ubt 03 16 CALCULATING MACHINING CYLINDER HEAD HEIGHT VERSUS COMBUSTION CHAMBER VOLUME U 03 17 OCTANE REQUIREMENTS FOR ROTAX ENGINES eere eene rrr nnns 03 17 RAVE VALVE OPERATION U u DI 03 17 FUNCTION OF THE ROTARY VALVE INTAKE SYSTEM
153. ssure Idle Stop Screw Idle stop screw adjusts the idle speed RPM by opening or closing the throttle plate butterfly Refer to your 5 Guide for the correct idle speed for your watercraft As a rule of thumb ad just the idle to approximately 1100 RPM www SeaDooManuals net Low Speed Screw Low speed screw is used in conjunction with the idle stop screw to maintain idle speed and smoothness Use the low speed screw to adjust the smoothness of the idle Experiment turning the low speed screw in and out in small incre ments until a smooth idle is obtained As the idle stop screw is turned in or out to raise or lower idle speed the low speed mixture is also affected The low speed screw is very sensitive and adjust ments should be made in small increments only For clarification if the idle stop screw is turned out to lower idle speed the low speed air fuel mixture will richen slightly and a small adjustment will need to be made with the low speed screw inward to compensate NOTE Io get a good feel for the correct low speed adjustment experiment with the idle stop and low speed screws You will find that a small adjustment with one of the screws requires and equal readjustment of the other Correct low speed adjustment will result in improved throt tle response Transition Circuit Transition circuit is made up of the low speed screw pilot jet bypass holes and pop off pres sure adjust the tra
154. ston is subject to damage It may seize or the aluminum on the exhaust side of the piston dome may melt Pre ignition is always pre ceded by detonation Causes of Detonation 1 Octane of the fuel is too low for compression ratio L 2 Air fuel mixture is too lean incorrect jetting air leaks varnish deposits in carburetor malfunction anywhere in fuel system 3 Spark plug heat range too hot F01D5WA 4 gnition timing too far advanced m M 1 Squish area initial timing off If the squish clearance is increased a loss in pow ignition component failure er will occur while too small a squish clearance 5 Compression ratio too high for fuel being used will lead to detonation improperly modified engine The squish clearance can be measured by insert deposit accumulation on piston dome or ing a piece of resin core solder into the combus head tion chamber rotating the engine through Top Dead Center removing the solder and measuring the thickness of the compressed solder muir er plugged restricten The solder should be inserted above and in line tune pipe outlet diameter too small with the wrist pin incorrect design of expansion chamber 7 General overheating restriction in cooling system debris in water pick up 8 Water entering combustion chamber SQUISH AREA Rotax cylinder heads incorporate a squish
155. t may have to be removed and the gear reposi tioned Refer to appropriate model year Shop Manual By removing the rotary valve shaft and reinstalling it with the drive gear in a different po sition with respect to the crankshaft gear and or valve shaft splines a different valve position may be established When a crankshaft rotary valve shaft or drive gear is removed or replaced it will be necessary to reverify the timing Apply Sea Doo injection oil on rotary valve surfac es before reassembling rotary valve cover Remove gauge Rotary Valve Cover Installation Install O ring and cover When installing O ring do not roll O ring into groove Instead place O ring in groove until it becomes necessary to stretch it to fit about half way around diameter Now pull O ring beyond cover and lay it into groove without twisting or rolling O ring then torque screws to 20 Nem 15 Ibfeft in a criss cross sequence W CAUTION Crankcase halves must be separated and crankshaft must not be present to install ro tary valve shaft assembly in crankcase 03 25 www SeaDooManuals net SECTION 03 ENGINE PREPARATION ROTARY VALVE IDENTIFICATION TEMPLATE 147 cut out angle 290 924 508 actual size A00A0YS 03 26 www SeaDooManuals net SECTION 03 ENGINE PREPARATION TEMPLATE cut out angle 290 924 502 actual size 132 cut out angle 290 924 504 actual size 010855 03 2
156. t number 3 returns a correction of 2 advanced and this is too much in this case You estimate the correction should be set to 1 advanced to align flywheel mark Back in the chart look to find 1 advanced This gives number 4 Enter this number with the programmer You recheck the timing with the timing light and found that the flywheel mark is still too advanced You know now that the correction made previously was not enough and you es timate the correction should be set to 2 re tarded to align flywheel mark Back in the chart look to find 2 retarded This gives number 6 Enter this number with the pro grammer You recheck the timing with the timing light and if the mark is aligned ignition timing is properly set c You found the flywheel mark retarded You must advance the ignition timing The programmer gives you the number 4 Referring to the chart number 4 returns a correction of 1 advanced and this is not enough in this case You estimate the correction should be set to 2 advanced to align flywheel mark Back in the chart look to find 2 advanced This gives number 3 Enter this number with the programmer SECTION 03 ENGINE PREPARATION You recheck the timing with the timing light and if the mark is aligned the ignition timing IS properly set Proceed as follows to adjustthe ignition timing with the MPEM programmer Connect the communication cable to the MPEM progr
157. t intake grate Aftermarket ride plate Aftermarket steering system Aftermarket throttle amp switch assembly Lightweight PTO Aftermarket pump nozzle with assorted sizing rings Aftermarket steering nozzle Aftermarket thrust cone Assortment of aftermarket impellers Cable or hydraulic operated trim system Aftermarket sponsons Heavy duty battery Heavy duty battery cables Bilge pump 03 32 Porting Specifications Radius 25 degrees BOOST PORT TRANSFER PORTS www SeaDooManuals net 5 1 5 2 0 mm 1 5 mm minimum 38 5 39 5 mm 39 5 mm max Piston Ring Cylinder Displacement and Compression Ratio Calculation Bore 82 00 mm Stroke 74 00 mm Combustion Chamber Volume 36 cc Displacement Calculation 3 14 Times the radius squared mm times the stroke mm divided by 1000 Radius is 1 2 the bore diameter Radius 41 mm 41 x 41 1681 Radius squared 1681 x 3 14 pi 5278 34 5278 34 x 74 stroke 390597 16 mm mm 2 cubic millimeters 390597 16 divided by 1000 390 597 cc s n x41 74 1000 Multiply by the number of cylinders 390 597 x 2 2 781 194 cc s Compression Ratio Calculation 390 597 cc s Combustion Chamber Cylinder Volume Volume Theoretical Combustion Chamber Compression Ratio Volume Combustion Chamber Volume 36 cc Cylinder Volume 390 cc 36 cc 390 cc 36 cc 36 cc 390 cc Cylinder Volume 426 cc 426 cc 36 cc 11 8 1 Compression Ra
158. t of the same size engine displacement at the same RPM Because the aperture size and degree of opening exceed that of a piston port en gine a greater air fuel mixture supply can enter the engine and remain in the engine without spit back Engine Operation Basically the rotary valve engine performs the same operation as the piston port 2 stroke en gine The only difference being the location and operation of intake 1 The intake port is positioned directly in the crankcase 2 Ihe opening and closing of the intake port is controlled by a rotary valve instead of the pis ton 3 he rotary valve is driven by the crankshaft in a counterclockwise direction Intake and Secondary Compression FO1D6TA 1 Fresh charge from carburetor As the piston starts its upward stroke the air fuel mixture is drawn into the crankcase from the car buretor via the intake port the rotary valve uncov ers the intake port At the same time the piston blocks the exhaust and transfer ports and compresses the air fuel mixture in the combustion chamber secondary compression 03 20 Ignition and Combustion F01D6UA 1 Fresh charge As the piston nears the top of the cylinder TDC the compressed air fuel mixture in the combus tion chamber is ignited by the spark plug The burning gases expand and push the piston down ward thus causing a power stroke Exhaust and Primary Compression FO1D6VA 1 Fresh charge for
159. ted by measuring actual combustion chamber temperatures A cold er spark plug one that dissipates heat more rapid ly is often required when engines are modified to produce more horsepower The proper heat range of the spark plugs is deter mined by the spark plugs ability to dissipate the heat generated by combustion The longer the heat path between the electrode tip to the plug shell the higher the spark plug op erating temperature will be and inversely the shorter the heat path the lower the operating temperature will be 03 66 A cold type plug has a relatively short insulator nose and transfers heat very rapidly into the cylin der head ouch a plug is used in heavy duty or continuous high speed operation to avoid overheating The hot type plug has a longer insulator nose and transfers heat more slowly away from its firing end It runs hotter and burns off combustion de posits which might tend to foul the plug during prolonged idle or low speed operation Generally speaking if you have increased horse power by 10 1596 you will have to change to the next colder heat range spark plug Sea Doo watercraft are equipped stock with NGK spark plugs BR7ES for all 587 engines and BR8ES for all the other engines The spark plug gap should be 0 5 0 6 mm 020 024 in for all engines These are resistor type plugs which help reduce radio frequency interference www SeaDooManuals net Design Symbols Used on N
160. teel progressive pitch 2 1 000 104 satin finish stainless steel 2 1 000 313 ring 11 21 progressive pitch 2 1 000 104 satin finish stainless steel 2 1 000 313 ring 15 21 progressive pitch 2 1 000 104 ae Ore satin finish stainless steel 2 1 000 313 ring 10 22 progressive pitch 2 1 000 422 a ee satin finish stainless steel 271 000 434 ring 11 21 progressive pitch 2 1 000 104 satin finish stainless steel 2 1 000 313 ring 10 22 progressive pitch 2 1 000 422 satin finish stainless steel 214 000 434 ring 10 22 progressive pitch 2 1 000 104 satin finish stainless steel 2 1 000 313 ring 10 22 progressive pitch 2 1 000 422 AR satin finish stainless steel 271 000 434 ring 04 9 www SeaDooManuals net SECTION 04 PROPULSION SYSTEM IMPELLER PITCH CHART NOTE The following chart could be used as a guide to help optimize pitch for your application 7000 TIME RPM seconds P f ni 15 S ZZ I 7 i 4 DA hi ri PEL 0 MAX BOAT SPEED MPH 010725 www SeaDooManuals net 04 10 ENGINE JET PUMP ALIGNMENT Alignment is necessary to minimize power loss and eliminate possible vibration and or damage to components Check alignment of your engine jet pump using the following special alignment tools NOTE The alignment tool is available through your dealer FO1L2RC 1 Housing P N 295 000 090 2
161. ter flow regulator valve Attach 2 hoses of 1 4 FOTETFA in hoses to the T fitting run 1 hose to the new fit 1 Water supply hose of regulator valve ting on the muffler which replaces the water flow 2 Regulated water to injection fitting at tuned pipe head regulator valve and 1 hose to the fitting on the 3 Water injected into the muffler tuned head pipe Procedure for Hard Jetting the Exhaust 4 Start the hard jetting procedure by installing a oystem no 200 Mikuni main jet in the fitting on the muffler and a no 150 Mikuni main jet in the fit ting on the exhaust tuned head pipe After an v CAUTION initial test ride of no more than 3 minutes stop When Hard Jetting an exhaust system and check the exhaust hoses for excessive small jets are used to regulate water flow temperature If you believe the temperatures These Jets are very prone to clogging by to be too high install a larger jet in both areas sand or debris The jets must be continually This is highly unlikely because the initial jet siz checked for blockage or system damage will es stated should be more than sufficient occur A cooling water filter is recommend 5 After verifying that the exhaust hose tempera ed ture 15 not excessive you can start testing the watercraft with smaller or larger jets in order to attain the performance desired 1 Remove the water flow regulator valve and re place the unit with a fitting that will thread into the muffler in its place
162. the areas of transfer port passages Also check for any overlap of the exhaust man ifold gaskets where the exhaust manifold joins the cylinders Before reassembling make sure that parts are free of any dust or particles 4 Check port alignment between the cylinder casting and the sleeve If the sleeve is off in one direction on all ports heat the cylinder in the oven at 176 C 350 F for 45 minutes Drop a rag that has been soaked in ice water into the sleeve and quickly align the sleeve with the cylinder casting Apply constant pressure with some type of heavy object not affected by ex treme heat to the top of the sleeve while letting the sleeve and cylinder cool down at room tem perature SECTION 03 ENGINE PREPARATION 5 Check piston to cylinder clearances ring end gap cylinder taper and out of round Check compression ratios and squish areas of both cylinders Make sure that they are equal to each other in both respects and that the proper fuel is used for the compression ratio and squish area of the engine 6 Assemble the engine using the correct seal ants where specified Rotary valve timing should be correctly set for your application Re fer to FUNCTION OF THE ROTARY VALVE IN TAKE SYSTEM in this section For maximum power output a dual carburetor setup should be used When converting a single carburetor engine to a dual carburetor type some very im portant changes need to be made the rotary valve cover i
163. timing can be checked with either the engine hot or cold Al so the ignition timing is to be checked at 3500 RPM with the timing light Between 3000 and 4000 RPM the spark advance does not change So when checking ignition tim ing at 3500 RPM a change in engine speed within 500 RPM will not affect the timing mark when checked with the timing light 03 59 www SeaDooManuals net SECTION 03 ENGINE PREPARATION Static Test All Engines 4 Install and adjust a TDC gauge in MAG side spark plug hole All Engines 1 Disconnect MAG side spark plug wire and con nect wire to grounding device then remove spark plug 2 Remove PTO flywheel guard 587 657 657X 717D and 717 Engines 3 Install timing mark pointer tool on engine using wing nuts previously removed TYPICAL 1 TDC gauge P N 295 000 143 on MAG side 5 Rotate PTO flywheel counterclockwise when facing it until piston is at Top Dead Center F01H5SA 1 Timing mark pointer tool P N 295 000 130 787 787X and 947 Engines 3 Remove middle screw securing the engine to the rear engine mount Reinstall screw with timing mark pointer tool bore 2 82 mm stroke 74 mm 787 FO1HALA TYPICAL 1 Adjust gauge dial at zero F06H05A 6 From this point rotate flywheel clockwise to 1 Timing mark pointer tool P N 295 000 135 reach proper specification according to the en gine Refer to the appr
164. ting Of ficial was incorrect talk to the Race Director The Race Director s decision is final in these matters The second most common problem occurs during a race because a racer misses a buoy and no offi cials witnessed the incident or the racer was called for a missed buoy and the racer believes they did not miss the buoy When missed buoys are not seen by a race official then the call against the racer in question cannot be made even when the error was captured on video tape Video tape evidence is not permissible by any sanctioning body If you feel that the call made against you was Invalid consult the Race Director The Direc tor will consult with the official making the call against you If that official wishes to retract the call on the buoy in question the decision will be reversed The Director will not reverse an officials call unless the Director witnessed the situation personally www SeaDooManuals net SECTION 01 GENERAL RACING INFORMATION While there are many examples of differences be tween officials and racers most can be solved without bringing the Race Director into the con versation An example of this would be a scoring error When a discrepancy arises in scoring that places you further back in the race than you thought was correct see the Chief Scorer The Chief Scorer will recheck the lap charts to deter mine if an error was made If no error is found the ocorer can explain to you how they arrived
165. tio 11 8 Compression Ratio Calculation Combustion Chamber Cylinder Volume Volume _ Corrected Combustion Chamber Compression Ratio Volume Cylinder volume with the piston just closing the exhaust port SECTION 03 ENGINE PREPARATION Increasing Compression Ratio To increase compression you must mill the head 3 millimeters from the plain surface and rework the squish area to a diameter of 83 millimeters with an inclination of 14 degrees Mill the head 3mm FOOD1CA minimum top dead center FOOD1DA THIS MODIFICATION REQUIRES THE USE OF HIGH OCTANE RACE FUEL 03 33 www SeaDooManuals net SECTION 03 ENGINE PREPARATION Intake Manifold Modification Using a portion tool modifications shown in the illustration Rotary Valve Timing 2mm 146 5 B T D C 64 A T D C 5 46 mm 43 7 lt 44 6 mm FOODIES 03 34 www SeaDooManuals net SECTION 03 ENGINE PREPARATION Exhaust Manifold Modification 5mm FOOD1FA Using a mill remove 5 millimeters for the cylinder side of the exhaust manifold The suggested ex haust system 15 a Factory Pipe using the variable water control system www SeaDooManuals net 03 35 SECTION 03 ENGINE PREPARATION 947 ENGINE MODIFICATIONS RAVE Valve Operation On the 947 the RAVE valves are controlled by the Multi purpose Electronic Module The MPEM measures two factors to control the RAVE valves engine RP
166. ton closes the exhaust port V WHERE C C R 2 Corrected Compression Ratio V4 Volume of a cylinder with piston just closing the exhaust port V Minimum combustion chamber volume FO1D60A 1 2 3 IDC 4 5 Exhaust port just closed Stroke www SeaDooManuals net CALCULATING MACHINING CYLINDER HEAD HEIGHT VERSUS COMBUSTION CHAMBER VOLUME Mies V Hu B 2 TU X WHERE H Material to be machined from face of cylinder head cm Measured combustion chamber volume cc V5 Desired combustion chamber volume cc V V Volume of cylinder CRp Desired compression ratio T 3 1416 B Bore of cylinder cm EXAMPLE Desired compression ratio CRp 14 0 1 V4 248 4 cc c cose es _ 21 5 cc 19 1 cc 0 BY 72Y nx 5 3 14 5 H 0 059 cm 0 59 mm 023 in SECTION 03 ENGINE PREPARATION OCTANE REOUIREMENTS FOR ROTAX ENGINES Following is a set of guidelines for a suggested relationship between uncorrected compression ratio combustion chamber squish band clear ance and octane requirements for an engine built to compete in racing These are only suggested guidelines and are not the only factors involved in the complete building of a reliable race ready en gine All Rotax engines will perform best on un leaded regular gasoline of the proper octane There is no advantage of using a higher octane fuel if the compression ratio
167. tuning What we have been considering and learning is pop off pressure what it is and what affects it What effect does this have on your fuel system Pop off pressure controls throttle response from just off idle until approximately 1 2 throttle As a rule of thumb piston ported and rotary valve en gines use generally higher pop off pressures as where reed valve engines require lower pop off pressures Spring Selection When changing the pop off pressure it is recom mended that you select a spring from the chart that combines with your needle valve size to ob tain the desired pressure If no spring size is ap propriate it is acceptable to take a spring of greater pressure and cut it shorter to achieve the correct pop off Use your gauge to verify the pop off Do not stretch lesser springs to increase pres sure as the metal has a memory and will eventu ally shrink back to its original size www SeaDooManuals net Pop off Pressure Chart Needle Valve Size Arm Spring Fuel Flow Chart NOTE This chart depicts the approximate amount of fuel that each circuit contributes to the total fuel flow of the Super BN S Fuel flow is in percentage F01D71A 1 96 of total fuel flow 2 Ihrottle position 3 High speed screw 4 Main jet 5 Transition circuit 6 Low speed screw Low Speed Circuit Low speed circuit contributes fuel all the way to full throttle All fuel circuits within the carb work
168. u will be allowed to choose your own number providing the number has not already been select ed by another rider Check with the IJSBA or your regional promoter prior to buying or painting num bers on your boat Most promoters have back grounds and numbers available for sale 2 If your watercraft model is not equipped with a flush bow eyelet it must be removed prior to Inspection and racing It is required that a length of nylon rope be used to replace the eyelet The rope will facilitate easy towing off the course by the Course Marshals in the event of a breakdown and prevent water entry into the hull When securing the rope ends in side the nose of the hull the eyelet retaining plate must continue to be used in order to pre vent the rope from pulling through 3 The pump intake grate must have at least one bar running the length of the inlet and must not protrude down more than 12 mm 0 473 in below the flat plane of the intake portion of the pump housing 4 The ride plate must not contain any fin or rud der type protrusions and aftermarket plates must stay within required dimensions 5 he rubber bumpers must be in place and se curely attached 6 The hull and body must not have any sharp edges torn or improperly repaired fiberglass 7 Steering must turn from lock to lock without binding 8 The handle bar grips must be secure 9 Aftermarket handle bars that have a cross bar must have padding on the cross
169. ull time dedication This means putting in 20 hours a day training promoting working on your equipment then racing and having all this come together to win the race 01 12 Winning the race is always the top priority but having the ability to promote your sponsors makes you even more valuable to them Your job off the track is as important for the image of your sponsors as it is to yourself Thus your day does not end as soon as the race Is over Being a champion watercraft racer also entails be Ing very strong and in great physical shape It takes a lot out of you to race a 60 plus MPH wa tercraft around the track with 13 other guys want ing to get pass you Physical cross training has made me stronger and given me an advantage Every advantage on the track even a small one can give big results at the end of the race Our sport is now in what think to be still in the developmental stage Because of this testing your PWC is very very important if you want to win My testing schedule is always an on going task of trial and error But my Sea Doo is always out front at the races The last thing is putting the above combinations all together on race day With good anticipation a little luck and all the right preparation you will have a successful day at the races or as for me and Sea Doo a couple of National titles and an overall World Championship Chris The Flying Fish Fischetti 1996 IJSBA Pro Runabout 785 National C
170. until the first turn buoy If you cut across in front of other riders you will be placed 1 lap down or black flagged In lieu of a black flag the race may be red flagged and you will be required to start with a dead engine and your tether in you hand This does not mean you can not change lines If you have a definite lead on another boat and you will not endanger them you can move in Getting around the first turn buoy in good position is very important If you are in back of the pack you will have a lot of trou ble getting around the other boats before you fin Ish In many cases a rider has been 279 or 39 to the first turn buoy and lost position because of water spray blinding their vision Use race goggles at least for the first few buoys You can duct tape the strap to the back of your helmet so you don t lose them when you pull them off Race smart Stay close to your competitor and capitalize on their mistakes Know the course Many times the leader has taken the wrong path with other riders following just to have a slower rider negotiate the course correctly and win 01 4 Be sure you race to the checkered flag Many rac es have been lost because the rider thought the white flag was waved then stopped on the next lap Flag men make mistakes Race to the check ered flag not 1 lap past the white Always race past the start finish line and between the 2 finish line buoys Many Expert and Pro racers on the IJSBA National Tou
171. will pay off in the long run The person in charge of the officials is the Race Director The Race Director orchestrates all activi ties on race day If you have a problem with a judgement made by an official and you cannot come to an equitable solution see the Race Direc tor The Race Director is in charge of settling dis putes The Race Director s calls are final at the race site If you feel the wrong decision was made you can file a written protest to the Race Committee of the sanctioning body under which the race was conducted Normally the protest must be accompanied with a protest fee If it be comes necessary follow the procedures outlined in your rule book for filing an official protest There has been documented cases where the Race Committee has reversed the decision of the Race Director however it Is rare he most common problems which arise be tween racers and officials occur at the start of the race Racers jump the start and then the race is red flagged or the rider and their holders are un happy because they feel a red flag should have been thrown but was not Because of these prob lems being most common it is recommended that you watch the start of the races preceding yours whenever possible Determine the type of calls the Starter is making and use the information to your advantage When problems arise and the call is made against you respond professionally It you believe that the call made by the Star
172. y the vor tex pressure and upward movement of the pis ton www SeaDooManuals net SECTION 03 ENGINE PREPARATION By doing this the large volume of air fuel mixture taken into the engine during intake is wholly re tained inside the engine and not partially expelled with the exhaust Combustion therefore is with a completely fresh charge Boost Port The boost port or finger port as occasionally re ferred to is a cavity in the wall of a cylinder The prime purpose of this port is to assist the clearing of burnt gases from the combustion chamber In doing so it allows a fresher charge for the next combustion phase and at the same time cools the piston dome This port comes into function af ter the third phase of engine operation or during the transfer stroke of the piston Unlike the transfer port the boost port does not connect to the crankcase a passage In the inder wall On the 587 engine the boost port com municates with the crankcase via a hole in the piston skirt On all 1994 and later Sea Doo en gines 587 657 717 787 and 947 the boost port is connected with the crankcase and functions much as a transfer port BASIC ENGINE THEORY Basically the 2 stroke engine performs the same operation as a 4 stroke However instead of com pleting the cycle in 4 stroke or 720 crankshaft ro tation the 2 stroke engine completes the cycle in only 360 2 stroke In other words the 2 stroke engine pisto

1998 SeaDoo Racing Handbook

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