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1971 Skee-Horse

1. Keep battery terminal connections tight and free from corrosion If corroded clean cable terminals and battery posts separately with a soda solution and a wire brush Inspect cables for fraying Figure 7 33 or broken strands 3 Keep electrolyte above the plates and separators at all times Ad here to manufacturer s instructions for maintaining fluid level Check electrolyte and add distilled water as necessary at weekly or semi monthly intervals Never add acid except when it is definitely known that some has been lost by spilling If water is added in freezing weather charge the battery to full charge at once Charg ing the battery will mix the water with the electrolyte and prevent water freezing in the battery 4 Keep the battery nearly fully charged at all times Check the state of charge at frequent intervals by making specific gravity readings with a battery hydrometer see Figure 7 33 Note that hydrometer reading is not accurate if water has been added re cently due to the fact that the water may not be mixed with the electrolyte Self discharge will cause storage batteries to become discharged and sulphated if they are not properly maintained in storage minimize self discharge store batteries in as cool a place as possible so long as the electrolyte does not freeze battery which has been allowed to Stand idle for a long period of time may be so badly damaged by sul
2. e Wohnson SKEE HORSE SERVICE MANUAL ki HORSEPOWER 2d MODELS 25 201R 25 201RS 25 201RA 25 201RSA 11 70 PART NO 261894 LITHO U S A OUTBOARD MARINE CORPORATION 1970 ALL RIGHTS RESERVED AVAILABLE IN ONE QUART CANS AND IN 6 PACKS FROM YOUR JOHNSON DEALER FUEL RECOMMENDATIONS The correct fuel mixture ratio is 24 parts of a good grade regular gaso line to one part lubricant For ease of measurement this is equivalent to one quart of lubricant to six gallons of gasoline one pint of lubricant to three gallons of gasoline or 1 3 pint of lubricant to each gallon of gasoline Use only Johnson Lubricant or a reputable automotive engine oil SAE 30 SD or SB Avoid use of low price third grade SA light duty oils DO NOT USE MULTIPLE VISCOSITY OILS SUCH AS 10W30 OR ANY OUTBOARD MOTOR OILS OTHER THAN JOHNSON OUTBOARD LUBRICANT EVEN THOUGH JOHNSON OUTBOARD LUBRICANT IS ADVER TISED AS A 50 1 RATIO LUBRICANT IT IS IMPERATIVE FOR SNOWMOBILE USE THAT IT BE MIXED AT A 24 1 GAS LUBRICANT RATIO DO NOT POUR GASOLINE OR LUBRICANT DIRECTLY INTO VEHICLE FUEL TANK USE AN APPROPRIATE CONTAINER FOR MIXING AND STORING THE FUEL To prepare the snowmobile fuel properly pour into a SEPARATE clean container half the amount of gasoline required and add all the required lubricant Thoroughly shake this partial mixture Next add the balance of gaso
3. A n 0 9 2 DIBSABHEMBLY 9 3 CLEANING INSPECTION AND REPAIR 9 6 CYLINDERS oi 9 6 GASKETS AND GASKET SURFACES 9 6 b dala 6 a 9 7 nA Pete iO 9 7 ASSEMBLY OF ENGINE 9 8 PISTONS WRIST PINS AND CONNECTING RODS ewer ease ee 9 8 PISTON RINGS mr 9 9 9 9 INSTALLATION 52 4 9 10 9 2 Figure 9 2 DESCRIPTION The snow machine is driven by a two cycle twin opposed cylinder air cooled engine see Figure 9 1 This section gives instructions for removal and overhaul of the engine Principles of two cycle engine op eration are discussed in Section 3 Trouble shooting procedures are given in Section 4 ENGINE REMOVAL Remove shroud Release two quarter turn wing fasteners and remove belt guard Keep fingers from between halves of secondary sheave when removing belt Movable half of sheave is spring loaded D Spread the secondary sheaves by pulling the movable half of sheave toward the steering column Work belt over top of movable half of sheave as shown in Figure 9 1 Work belt between primary and secondary sheave See Figure 9 2 Disconnect neutral lockout cable from actuator arm and move belt between actuator arm and primary sheav
4. ad REVERSE REVERSE IDLER BEARING e EE NE tm SECONDARY a SLEEVE ae DRIVE RAMP __ SHOE d BUSHING SECONDARY SPRING Figure 10 13 10 7 ROD 10 8 SECONDARY TRANSMISSION SHEAVE AIR VENT SHAFT INPUT SHIFTER DOG CRADLE CHAIN SPROCKET SHAFT OUTPUT FORWARD OPERATION SHIFTER PINION GEAR CEVIS PINION GEAR ENGAGED FORWARD OPERATION Figure 10 14 Assemble Secondary sheave assembly on transmission input shaft in reverse order of disassembly Engage spring ends in holes in movable sheave and end cap Preload spring by holding end cap stationary and rotating movable sheave clockwise to engage next ramp on end cap approximately 1 3 turn See Figure 10 13 Torque sleeve screw to 00 00 ft lbs torque and secure with lock washer tabs REVERSING TRANSMISSION DESCRIPTION In forward operation the power flow from the secondary sheave is transmitted to the input shaft and gear directly to external spline clutch dog with engages the output shaft gear Therefore input and output shafts rotate in the same direction See Figure 10 14 At thistime the pinion gear shaft and pinion gear are retracted from the thru shaft gears In reverse operation the power flow from the secondary sheave to the input Shaft and gear is because of the release of the dog clutch and the engagement of the pinion gear see Figure 10 15 trans
5. ring can be removed when the linkage is disassembled from the shaft CLEANING INSPECTION AND REPAIR Clean all parts with a cleaning solvent such Trichloroethylene and blow dry with compressed air Inspect shafts and output shaft splines for wear Turn bearings by hand discard any which do not rotate smoothly or which have excessive play Inspect clevis clutch dog and cradle liner for wear or damage Inspect ring on pinion gear shaft Replace if required ASSEMBLY AND ADJUSTMENT b Install input shaft and gear Use Loctite bearing mount on the and LD of the sealed bearings see Figure 10 13 Insert pinion shaft and assemble shim thrust washer thrust bear ing thrust washer pinion gear and bearing assembly and shifter dog clevis Install output shaft output gear and retaining ring Install bearing in gearcase using Loctite bearing mount on and Mount transmission to chain case with four screws Gear backlash should be 000 when the pinion gear shaft retaining ring is held against the outside of pedestal housing This may be adjusted by means of shims installed on the pinion shaft and these are available in 002 003 004 005 thousandths See Figure 10 17 Remove housing output shaft and gear Apply Loctite stud lock to clevis socket screw Complete pinion assembly Install clutch dog assembly and output gear on shaft splines and assemble transmission
6. 17 15 BELT TENSION 1 16 ALTERNATOR 7 16 TROUBLE SHOOTING 7 16 CHECKING RECTIFIER DIODES 7 16 ALTERNATOR COIL REPLACEMENT 17 17 WIRING DIAGRAMS AT BACK OF MANUAL 1 2 MAGNETO BATTERY GROUND LIGHTS STARTER Figure 7 1 GRAHAM DESCRIPTION The ignition system consists of the magneto drive coils condenser breaker point assembly ignition coils ignition light switch see Figure 7 1 spark plugs and the necessary wiring Because the engine is a two cycle twin opposed cylinder design a single breaker point assembly and single lobed cam are used with two ignition coils to supply spark simultaneously to both cylinders An automatic spark retard advance system has been incorporated to provide easier starting The electrical system consists of the alternator coils head and tail lights light and ignition switches and wiring In addition on models equipped with electric starting the electrical system includes the stor age battery electric starting motor starter solenoid and bridge recti fier The alternator coils produce alternating current which changes in frequency and voltage in proportion to engine speed On models having electric starting this alternating current output is rectified changed to direct current by a diode bridge rectifier and used to charge the bat tery Direct current is then used to power the head and taillig
7. BOLT PLUNGER AND ROD ASSEMBLY KPLATE Figure 10 2 SERVICE TOOL END CAP ASSEMBLY PLUNGER AND ROD ASSEMBLY Figure 10 4 DESCRIPTION This section gives complete service instructions on the snowmobile drive train system A brief discussion of the power flow system is in cluded in Section 3 PRIMARY DRIVE REMOVAL OF PRIMARY SHEAVE ASSEMBLY After removing the transmission belt as described in Section 9 the primary sheave assembly can be removed using the following procedure a Remove starter assembly b Remove ratchet mount Attach Service Tool 113971 to flywheel with three bolts from ratchet mount see Figure 10 1 Use flat open end wrench Service Tool No 404032 on the square nut on back side of the fixed sheave e While holding the service tool attached to the flywheel rap the open end wrench with a rawhide mallet in counterclockwise direction Power take off end of crankshaft has right hand thread After nut is loosened the primary sheave assembly can be turned off the crankshaft DISASSEMBLY OF SHEAVE WHILE ON ENGINE a Remove one screw loosen other screw attaching neutral lockout bracket to chain case Move bracket downward b Remove belt see Section 9 Remove two screws securing lock plate to end cap assembly see With flat open end wrench Service Tool No 404032 on inside and 1 1 8 deep socket
8. Figure 1 2 1 3 2 1 SECTION 2 SPECIFICATIONS TABLE OF CONTENTS SPECIFICATIONS 27 2 2 TORQUE SPECIFICATIONS 2 3 2 2 Before repair your proceeding with any or maintenance for own protection see SPECIFICATIONS CAUTION Snow Vehicles are not manufactured for highway use and the manufactur r does not represent that they are equipped with all the de vices legally required for such use Length 42 1 PE e nci a 37 oc rd 47 1 2 Mehes with windshield 37 inches without windshield 3255 2 cycle opposed twin BRI ERR RM son s Maximum 30 hp at 3800 rpm Starter Model25 201R and 25 201RA Manual rewind Model 25 201RS and 25 20185 Electric and manual rewind Variable speed drive Centrifugal operated sheave Engages V belt Overall fw te SERRE EL PS Pee eee eee 9 0741 Final drive 4 ASA 39 double chain Sprocket 16 to 42 Reverse transmission Dog clutch and bevel gears Muffler Single Tuned muffler for quiet operation Brake 4 Lage typ
9. length of 73 1 4 inches Examine bushing in instrument panel and starter housing for sharp edges and rough surfaces that might cause rope fraying File and polish as necessary REASSENBLY a Place inside spring end loop over pulley anchor pin Place out side spring end loop between pins on fixture base Insert handle shaft with bushing through pulley bore and into fixture base Use fixture crank to wind spring counterclockwise until tight Re lease at least one turn continuing to release until loop end spring lines up with hole drilled through edge of pulley Slide one end of pin through holes in pulley and spring loop Carefully remove the hand crank and bushing Lift pulley off base plate holding spring in pulley Place pulley and spring into starter housing making certain that spring loop is lined up exactly with pin in starter housing Press pulley into starter housing forcing out pin which held spring Apply standard Oil Rykon EP 2 to spindle and spindle bushing CAUTION Many lubricants including OMC Type A solidify in cold weather and will make the starter inoperative 1 Install spindle spring washer friction ring and bushing Fasten with screw washers and nut Tie knot one end of starter rope If installing a new rope be sure length measures 73 3 4 inches Fuse nylon strands over an open flame at each end for about one half inch Rope end must be stiff to hold in
10. necting test leads to adjacent terminals on rectifier assembly and noting the reading see Figure 7 45 Reverse the test leads and again note the reading If both readings are very low or if both readings are very high the diode is defective A good diode will give one low reading and one high reading Repeat the test procedure for the other diodes by connecting the test leads between adjacent terminals If a test light is used light should show with connections in one direc tion only If lamp lights or fails to light in both directions the diode is defective Connect leads to correct terminals See Figure 7 45 and wiring diagram at end of manual ALTERNATOR COIL REPLACEMENT a Remove flywheel as described under Magneto Removal b Disconnect alternator coil lead see Figure 7 14 Remove alternator coil assembly d Install and connect new alternator coil assembly Make certain that coil laminations are flush with bosses on fan housing Reassemble as described on page 7 7 CIRCUIT RECTIFIER BREAKER Figure 7 45 SECTION MANUAL STARTER TABLE OF CONTENTS CLEANING INSPECTION AND REPAIR 8 3 RE ASSEMBLY B NW M E B B W k 8 3 STARTER ROPE REPLACEMENT 8 4 DESCRIPTION The manual starter converts straight line motion to rotary motion necessary to crank the engine Pawls on the starter pulley engage the flywheel ratchet when the star
11. phation that it can never be restored to normal charge condition Batteries should be recharged every 30 days to prevent this damage Disconnect one of the battery leads before charging battery storage temperature is hot more frequent charging will be necessary water if necessary before charging to bring electrolyte to proper level Fully charged batteries have been known to withstand temperatures as low as 90 F a discharged battery will freeze at about 19 perhaps causing bursting of both the cell and battery cases BATTERY TESTING a Make sure battery is charged as described under SLOW CHARGING Hydrometer readings taken on partially charged bat teries are unreliable for the following test b Measure specific gravity of electroyte in each cell and compare readings with the following if cell readings are between 1 250 and 1 290 the battery is ready for use Any variation in the specific 7 12 SOLENOID Figure 7 34 WINDINGS gravity between cells within this range does not indicate a defective battery Readings should be corrected to 80 Fahrenheit for com parison If this specific gravity of any cell falls outside this range 1 250 to 1 290 replace the battery BATTERY CHARGING For best performance a good battery should be fully charged before being returned to service DO NOT recharge the battery by the fast charge method This method does not restore the full charge and also sho
12. two crankshaft revolutions or four strokes are required for each power cycle In a two cycle engine only one crankshaft revolution is required per power cycle In two cycle engine the ignition of the fuel air mixture occurs as the piston reaches the top of each stroke expansion of gases drives the piston downward see Figure 3 1 Toward the end of the downward stroke ports which lead from the cylinder to the exhaust system are uncovered expanding exhaust gases flow into these ports reducing pressure in the cylinder Immediately after intake ports are opened These ports connect the cylinder with the crankcase where a mixture of fuel and air has been developed by earburetion lhe downward motion of the piston compresses this mixture and forces it through the intake ports into the cylinder See Figure 3 2 The inrushing charge of the fuel air mixture helps to eject scavenge the last of the exhaust gases from the cylinder At this point the mo mentum of the flywheel is required to return the piston to the top of the cylinder As the piston begins its up stroke it closes the intake and exhaust ports and begins to compress the fuel air mixture trapped in the cylinder See Figure 3 3 The upward motion of the piston also re duces the pressure in the crankcase The resulting crankcase suction opens leaf valves which admit a fresh charge of air and fuel from the carburetor into the crankcase thus preparing for the next pow
13. 2 Loosen muffler clamps 3 Disconnect tie rods from steering column arm 4 Remove steering limit bolt and swing arm up 5 Muffler can now be removed from well MUFFLER REASSEMBLY Reassemble muffler in reverse order making sure to take an equal number of turns on the muffler clamp nuts Torque nuts to inch pounds TABLE CONTENTS LIBASSEMBLE 22234 CLEANING INSPECTION AND REPAIR REASSEMBLY sc win DHIVE CHAIN ae saati e 2342224 LUBRICATION nog vua e ADJUSTMENT 0 2 cab eee 2 509 REMOVAL AND INSTALLATION A QV mai BRARN ra EX tos oon nis REMOVAL tomes bers 44 4 4 SECONDARY DRIVE cana ced DISASSEMBLY CLEANING AND INSPECTION REVERSING TRANSMISSION DESCRIPTION REMOVAL AND DISASSEMBLY CLEANING INSPECTION AND 59 ASSEMBLY AND ADJUSTMENT REVERSING TRANSMISSION LINKAGE DESCRIPTION erre pru mum om eae ADIUSPMENT SHIFT CONTROL ROD ADJUSTMENT 10 1 SECTION 10 DRIVE TRAIN 10 2 Figure 10 1 END
14. Faulty fuel pump or pulse line e Fuel cap vent clogged High speed nozzle or jet clogged Dirt or packing behind needles and seats Choke partly closed i High speed needle set too lean j Breaker points burned dirty or improperly gapped d Timing out of adjustment Engine runs at high speed only by using hand primer a Fuel lines or passages obstructed b Fuel line leaks or fuel filter obstructed Fuel pump not supplying enough fuel Leaf block gasket reversed Dirt or packing behind needles or seats f Carburetor adjustments Fuel cap vent clogged Reed block gasket reversed RUNNING HIGH AND LOW SPEED 1 Engine overheats a Incorrect gas lubricant ratio or improperly mixed fuel b Engine not assembled correctly during re pair binding Lean mixture carburetor adjustment 2 Engine stops suddenly or freezes up a No lubricant in gas or no fuel b Fuel connector faulty Cylinder or crankshaft scored gt e d Bent or broken rod crankshaft or stuck piston e Ignition failure f Frozen bearing Engine knocks excessively a Incorrect gas lubricant ratio b Spark plug wrong heat range c Flywheel loose Crankshaft end play excessive Carbon in combustion chambers and exhaust ports or on pistons Worn or loose bearings pistons rods wrist pins g Loose assemblies bolts or screws h Manual starter not centered Exce
15. If acid is spilled flush it off at once with plenty of clear water and neutralize with a solu tion of ammonia or baking soda Connect battery cables making sure clamps are tight on battery posts to insure good contact Apply a coat of petroleum jelly to exposed areas of the battery posts and clamp connectors to retard corrosion CAUTION Correct battery polarity is extremely important Battery must be connected with negative post black lead to ground and positive post red lead to starter solenoid If positive post is connected to ground damage to the charging system will result See Figure 7 31 BATTERY SERVICING Check outside of battery for damage or signs of abuse such as broken case or broken cover Check inside of battery by removing vent caps 1 11 and inspecting for low electrolyte level If battery shows signs of CHARGED DISCHARGED serious damage or abuse it should be replaced Visually inspect the 1 battery for the following 1 Corrosion 2 Frayed or broken cables 3 Cracked case or cell covers 4 Loose hold down clamps EJ 9 Low overfilled electrolyte NAH ibat BATTERY CARE Check the following at regular intervals 1 Clean battery top and terminals by washing with a solution of am monia or baking soda Keep vent plugs tight so that solution does not enter cells After washing flush top of battery with clean water
16. 474 5 52 1 22 mid Magneto drive coil resistance uc puo 8 ohm Ignition coil primary resistance 1 5 ohm Ignition coil secondary resistance 10 000 ohms Lighting coil resistance 06A to 078 Dim Battery 12 volt Prestolite Type 9948X or equivalent with a mini mum 32 ampere hour rating and with a minimum of 2 2 minutes cold starting at 150 amperes discharge 0 Fahrenheit and a second voltage reading of 7 8 volts Dimensions in inches are approximately 7 3 4 long 5 1 8 wide and 7 1 4 high to top of terminals Weight dry 17 lbs wet 21 4 lbs Electrolyte to fill 0 44 U S gallons Specific gravity 1 265 Engine Rore aida 2 3 4 2 1 4 inches Piston displacement 26 7 cubic inches 437 cc Compression TANG are oor eek oe en ee 6 8 to 1 Cylinder compression bees Minimum 105 Rims diameter pes die SP ON 2 3 4 inches TRGB EEE cw cue duro qu Fe Chie ee PES BS 52822 1 18 inch Clearances Piston Wrist pin sa gt press fit who ee aes 007 017 Piston ring ring pProoVe 002 004 Cylinder piston of piston to cylinder 012 015 Bottom of piston to cylinder 006 008 Specifications and features may
17. 9 11 Reassemble neutral lockout bracket to chain case 10 4 CHAIN OIL FILL PLUG Figure 10 8 Actorum n IDLER SPROCKET RETAINING RING d 4 gt 4 A ADJUSTING SCREW i Figure 10 10 DRIVE CHAIN LUBRICATION The drive chain and sprockets are lubricated by the chain running through an oil bath in the bottom of the chain case Check oil level by removing oil fill plug Oil should come up to bottom of oil fill hole See Figure 10 8 Fill with Type ESSO Gear Oil GX75 80 It will hold approximately 4 oz Replace plug ADJUSTMENT Total slack must be 1 4 1 16 as shown in Figure 10 9 Remove chain case cover Note Oil will drain when cover is removed Place a straightedge over chain at the sprockets press on center of chain and measure slack at this point If the chain requires adjustment use the following steps l Loosen jam nut see Figure 10 9 2 To tighten chain turn adjusting screw clockwise 3 To loosen chain turn adjusting screw counterclockwise 4 Retighten jam nut to 10 12 ft lbs 9 Apply EC1022 adhesive in groove of chain case prior to assembling seal Insert seal into groove with joint in line with top right cover mounting screw hole Replace chain case cover Torque the 6 screws 60 80 inch lbs 6 Replace oil in chain case See Drive Chain Lubrication above REMOVAL AND INSTALLATION a Remove chain
18. Escape of compression past the piston rings is referred to as blow by and is indicated by dis coloration or carbon formation on the piston skirt Cylinder bores normally wear with operation of the engine The de gree of wear will vary with length of operation efficiency of lubrication and zeneral condition of the engine Excessive cylinder wear results in loose fitting pistons and rings causing blow by loss of compression loss of power and inefficient performance Piston rings are formed in such a manner that when installed on the piston they bear against the cylinder wall with a light even pressure Excessive ring pressure against the cylinder wall increases friction causing high operating temperature sluggish performance and abnor mal wear or scoring Insufficient pressure allows blow by which re duces pawer and causes overheating and carbon formation on the piston skirt Since the ring tends to flex as it follows the cylinder contour during engine operation clearance gap must be provided between the ring ends to prevent butting The ring gap also allows the ring to expand elongate as engine temperature rises during operation Insufficient gap clearance will cause the ring to bend or warp as it flexes and ex pands excessive gap clearance will permit loss of compression Compression leakage may also occur at the spark plugs A cracked spark plug insulator will cause similar trouble Although compression i
19. RVICE TOOL 378103 Figure 7 13 Remove two screws to disconnect primer from chassis See Fig ure 7 6 Remove cover from fuel gauge then remove fuel gauge cable from fuel tank See Figure 7 7 Disconnect choke cable from choke lever arm at carburetor Loosen set screw then pull cable through projection on carburetor See Figure 7 8 Instrument panel can now be pulled back from air duct See Fig ure 1 9 Remove pulse line from fuel pump See Figure 1 8 Remove fuel inlet line from carburetor inlet elbow pull through air duct and drain See Figure 7 10 Remove fuel inlet line from fuel pump See Figure 7 10 Remove three bolts securing manual starter assembly See Fig ure 7 10 Remove three screws holding air filter See Figure 7 10 Air duct can now be removed Remove eight screws and separate outer fan housing from inner fan housing See Figure 7 11 Remove three bolts securing ratchet mount assembly to flywheel See Figure 7 11 Hold flywheel with bar from flywheel puller and turn flywheel nut off crankshaft See Figure 7 12 Secure flywheel puller Service Tool 378103 to flywheel with 5 16 8 screws and remove flywheel from crankshaft See Fig ure 7 13 The magneto drive coils alternator coils breaker points and con denser are now accessible for servicing See Figure 7 14 BREAKER POINTS CONDENSER ALTERNATOR LIGHT COILS Figure 7 14 u Disconnect primary leads from termina
20. Speed Screw Throttle Shaft Idle Speed Mixture Screw Choke Valve Choke Shutter Choke Friction Ball Choke Friction Spring Check Ball Welch Plugs Check Valve Nozzle Inlet Needle Hinge Pin Inlet Tension Spring Hinge Pin Retaining Screw Inlet Control Lever Diaphragm Gasket Metering Diaphragm Diaphragm Cover High Speed Mixture Screw Fuel Hose Elbow Inlet Line Screen Choke Shaft High Speed Knob Ind INTAKE HOLE FOR MANIFOLD FUEL PUMP GASKET PULSE ACTION 6 6 Clean inspect and immediately reassemble the leaf valve assem FUEL PUMP bly rather than leave it apart for reassembly later BODY e The leaves are designed to maintain contact with the leaf valve GASKET body and to spring away from the leaf valve body when predeter mined pressure is exerted against them Attach the leaf valves and back stop to the leaf valve body then examine leaves carefully to make certain that they lie flat against body f Check tightness of leaf valve retaining screws and tighten any that appear loose INSTALLATION a Secure leaf plate assemblies to base using a new leaf plate gasket Align leaf plate and base assembly on crankcase Install intake manifold on crankcase using a new intake manifold gasket Be certain that elongated hole in gasket and base plate aligns with passage in intake manifold Obstruction of this passage will pre Figure 6 10 vent fuel pump operation
21. after a very few seconds of running or gets hot instantly stop testing Disassemble starter and check for shorts Stalled Torque Test a Connect a voltmeter between the starter terminal and motor frame Using a torque wrench to stall motor armature see Figure 7 40 connect starter motor through an ammeter to a 12 volt battery Voltmeter reading should be approximately 10 volts during this test Torque should be a minimum of 108 inch pounds or 9 foot pounds and current should be maximum of 405 amperes CAUTION If motor smokes or gets hot instantly stop testing disassemble starter and check for shorts Use only fully charged 12 volt battery when making stalled torque test Obtain readings as rapidly as possible to prevent starter overheating Allow suf ficient time for starter to return to room temperature if it is necessary to repeat stalled torque test Check each armature coil for open circuits by rotating torque wrench handle through a 180 degree after initial torque reading has been noted This must be done quickly Torque should be uniform through this arc although reading will decrease slightly each time brush moves from one commutator segment to another If an appreciably wide area is found in which torque is very low disassemble starter and check armature INSPECTION OF STARTER MOTOR c Check armature growler for shorted turns see Figure 7 41 NOTE
22. alignment is necessary when skis are not parallel with each other and the vehicle body with the steering bar in the normal straight driving position b Place steering bar in normal driving position c Loosen jam nuts at outer end of tie rods See Figure 11 2 Remove lock nuts from outer ball joints e Turn ball joint clockwise to toe skis out or counterclockwise to toe skis in f Tighten jam nuts when skis are parallel with each other and snow mobile body Install lock nut and ball joint in steering arm Torque nut to 18 20 ft Ibs TRACK AND SUSPENSION TRACK TENSION ADJUSTMENT Track tension must be checked after the first ten hours of operation and then every 25 hours or as required to maintain efficient economical operation Improper adjustment will result in undue wear to the track and drive components Track tension is checked when the track is not supporting the weight of the snowmobile and the pivot arms are pulled down Track tension is correct if the distance from the bottom of the pivot arm bearing bore to the bottom of the adjusting bracket is 2 7 8 1 32 See Figure 11 3 If adjustment is necessary perform the following steps on both sides of the vehicle a Vehicle should be in right side up position with track off the ground b Loosen track tension lock nuts and lock nut on pivot arm adjusting screw c Turn pivot arm adjusting screws to obtain the correct track ten sion as shown in Figure 11 3
23. assembly through a drive chain to the front axle The ratio between the secondary sheave assembly and the front axle is 16 42 Optional sprockets are available to change these ratios for special applications REVERSE TRANSMISSION The reverse gear is designed as part of the secondary drive In Forward gear the input shaft drives the output shaft directly by means of a dog type clutch In Reverse gear the dog clutch is released while a gear set engages to reverse rotation of output shaft Shifting must be done with the engine at idle and machine at rest 2000 RPM WITH NEUTRAL LOCKOUT ROD DEPRESSED SECTION 4 TROUBLE SHOOTING TABLE OF CONTENTS DESCRIPTION 2 auras 4 2 COMPRESSION 4 4 2 SPARE PLUGS scar 4 3 TROUBLE SHOOTING PROCEDURES 4 4 4 2 DESCRIPTION This section provides trouble shooting procedures for the snow ma chine Steps to be followed in determining causes of unsatisfactory per formance are outlined A Trouble Check Chart at the end of this section lists causes of unsatisfactory performance Being able to locate the cause of trouble in an improperly operating snow machine is as important as being able to correct the trouble systematic approach to trouble shooting is important if the trouble is to be located and identified in minimum time Any service operation can be
24. case cover b Loosen chain see ADJUSTMENT above c Remove screw and washer from upper drive shaft d Remove sprocket and chain from upper shaft Remove retaining ring to release idler sprocket if additional clearance is required to remove chain See Figure 10 9 e Chain can now be removed from lower sprocket INSTALLATION a Assemble in reverse order of disassembly b Adjust chain per ADJUSTMENT above c Add chain lubricant per LUBRICATION above REPAIR broken drive chain can be repaired with master links available from your dealer 10 5 CHAIN CASE IMPORTANT if chain case or engine has been removed care must be used to maintain the dimensions shown in Figure 10 11 Torque all screws and the tie rod nut to 18 20 ft lbs BRAKE DESCRIPTION The brake is caliper disc type with long lasting fibre pads pucks ADJUSTMENT Brake adjustments can be made by removing the cotter pin and turning FIXED 2 574 the castellated nut clockwise to tighten brake Turn the nut until there PRIMARY ME ASUBED AT is a slight drag on the brake then back the nut off one notch and rein HE BALANCE PADS stall the cotter pin See Figure 10 12 IMPORTANT Be certain there is proper movement of the brake lever control to permit use of the parking lock Loosen control cable locknut and adjust cable nut to obtain proper control lever movement See Figure 10 12 Tighten locknut REMOVAL a Remove cotter pin and loosen
25. commutator thoroughly removing all traces of metal chips or sanding grit and recheck armature on growler Inspect armature insulation for indications of overheating or dam aged windings Clean off any deposits of carbon which may con tribute to later failure of the windings NOTE Starter motor components should not be washed off in cleaning solvents Most solvents will soften varnish insulation used on armature and field windings All starter motor components can be cleaned ade quately with a clean cloth or soft brush Cleaning end heads in solvent may dissolve the oils that have impregnated into the arma ture shaft bearings If these oils are removed bearing or arma ture shaft wear can be expected Cleaning of armature in solvent will leave oily residue on the commutator segments causing arcing between the commutator and brushes Brushes b Inspect the brushes replace if worn to one third their original 3 8 length or if damaged or cracked Replace brush springs if weak Inspect brush springs Springs should have a pressure of 35 to 90 ounces when compressed to 9 32 inch Measure brush tension with scale hook under brush screw or under bend in brush spring and take reading as brush just leaves commutator Pull off spring scale must be directly opposite line of force exerted by brush spring Figure 7 41 CORRECT Figure 7 43 1 15 iil 7 16 STARTER BELT TENSION ADJUSTMENT
26. fuel into the crankcase before starting see Figure 6 1 FUEL LEVEL jH FUEL FILTER AND PUMP GAUGE CARBURETOR PULSE LINE ia PPE LANE CRANKCASE PRIMER Y FUELRETURNLINE FUEL LINE FUEL PRIMER SUPPLY LINE Figure 6 1 CARBURETOR The carburetor used on this snowmobile is the diaphragm operated HD series Tillotson The carburetor should be cleaned and inspected at regular intervals depending on service conditions Clean the entire carburetor by flushing with fuel and blow dry with compressed air before disassembly The carburetor should be inspected for cracks in the casting bent or broken shait loose levers or swivels and stripped threads REMOVAL Select a clean work area Dirt and carelessness are the cause of most carburetor trouble ad NYLON PIVOT PIN EE b c Remove throttle cable using the following procedure Depress thumb throttle lever Hold throttle in open position Slip end of throttle cable through nylon pivot pin Loosen jam nut on intake manifold and turn cable fitting out of manifold See Figure 6 2 Remove choke cable by loosening set screws on choke swivel pin and carburetor projection and pulling cable through projection See Figure 6 7 CAUTION Some solvents and cleaners have a damaging effect on the syn thetic rubber parts used in carburetors It is best to usea petroleum product for cleaning Do not use alcohol lacquer acetone thin
27. line necessary to bring the mixture to the required ratio of 24 1 Again thoroughly agitate the mixture A clean funnel equipped with a fine screen should be used when pouring the fuel mixture into the vehicle 24 to 1 lubricant is prediluted to provide excellent mixability with gaso line at low temperatures The addition of this dilutent does not in any way affect the lubrication qualities of the lubricant Whenever is is necessary to mix fuel and lubricant at temperatures below O F the lubricant should be prediluted with gasoline to improve its mixability The lubricant should be prediluted with approximately one part gasoline to one part lubricant Predilution of the lubricant should take place with the lubricant temperature above 0 F Do not use kerosene or fuel oils for pre mixing INTRODUCTION SECTION 1 INTRODUCTION SPECIFICATIONS GENERAL SNOWMOBILE INFORMATION TROUBLE SHOOTING TUNE UP PROCEDURES FUEL SYSTEM IGNITION AND ELECTRICAL SYSTEM MANUAL STARTER ENGINE DRIVE TRAIN STEERING TRACK AND SUSPENSION LUBRICATION AND STORAGE 1 2 The snow machine has been designed and built for dependable high performance It is important to every snow machine owner to be able to receive skilled and thorough service for his vehicle when necessary It is important to the service dealer tobe able to offer the type of skilled service which will maintain the customer s satisfaction This
28. manual together with the regularly issued service bulletins and Parts Catalogs provide the serviceman with all the literature necessary to service the Skee Horse snowmobiles An effort has been made to produce a manual that will not only serve as a ready reference book for the experienced serviceman but will also provide more basic informa tion for the guidance of the less experienced man The Parts Catalogs contain complete listings of the parts required for replacement In addition the exploded views illustrate the correct sequence of all parts This catalog can be of considerable help reference during disassembly and reassembly The Section Index on page 1 1 enables the reader to locate quickly any desired section At the beginning of each Section is a Table of Contents which gives the page number on which each topic begins This arrange ment simplifies locating the desired information within this manual Section 2 lists complete specifications on the 1971 snowmobiles All general information including 2 cycle engine theory trouble shooting and tune up procedures are given in Sections 3 through 5 of this manual Figure 1 1 sections 6 through 11 provide fully illustrated detailed step by step disassembly and reassembly instructions and adjustment procedures Section 12 provides lubrication and storage information In this way the texts treat each topic separately theory and practice are not intermixed This makes it unn
29. of rod to make cer tain that cap and rod are correctly aligned see Figure 9 24 If misaligned offset edge will be felt with pencil point Tighten connecting rod cap screws together If alignment is satisfactory tighten connecting rod cap screws to specified torque If align ment is necessary tap into alignment with drift punch Check for binding Bearings and retainers must float freely on crankpins Install crankshaft seals in crankcase halves Coat a new gasket with Perfect Seal 74 Place gasket on one crankcase half If gasket requires trimming be sure to use a very sharp cutting tool Uneven edges may result in crankcase leakage NOTE It may be necessary to heat crankcase halves with a heat lamp for approximately 15 minutes This allows easier installation of crankshaft f Replace crankcase alignment roll pins driving in carefully with a hammer Replace all crankcase screws and tighten to specified torque EXTRACTOR EXTRACTOR PART 261129 HALF SHELLS PART 261131 RETAINING RING PART NO 261132 Figure 9 21 Figure 9 22 4 930 001 Figure 9 23 9 10 g Check crankshaft end play It should not exceed 025 Crankshaft tapered end must be kept clean free of grease fingerprints before installation of primary sheave assembly CYLINDERS a Install cylinders to crankcase using new gaskets Use a ring compressor Special tool 426020 to install pistons in c
30. or as required Check Track Alignment See Section 11 Biannual see below Annually see below Clean or install new Fuel Pump Filter Screen Clean Filter Screen under Fuel Inlet Elbow The carburetor is equipped with an air filter that should be cleaned during the operating season and at the end of the season for storage To clean filter remove air cleaner cap screens and filter See Fig ures 12 3 and 12 4 Wash filter in clean gas lubricant mixture and shake If compressed air is available blow dry from the inside AIR FILTER FUEL FILTER FUEL PUMP Exercise care to prevent fuel when removing fuel filter when engine is hot The fuel filter is attached to the fuel pump See Figure 12 5 To inspect for sediment or water accumulation back off the mounting screw approximately three turns counterclockwise and remove the cover together with the screen gasket and mounting screw Remove and wash filter screen with clean gasoline and brush Assemble filter as shown in Figure 12 6 being careful to assemble gasket and filter screen on fuel filter cover Tighten mounting screw securely with screwdriver do not over tighten m zu Exercise care to prevent fuel spillage in removing fuel line when engine is hot The carburetor fuel inlet screen should be cleaned annually To clean screen remove fuel line and fuel inlet elbow Do not remove scr
31. pulley Turn starter pulley counterclockwise to make sure starter spring is fully wound After spring is fully wound allow it to unwind one turn so that pulley rope hole aligns with housing rope hole Insert rope through pulley and starter housing Seat rope knot firmly in pulley Tie a slip knot in starter rope and allow pulley to rewind Install pawls retainers and screws 8 4 Figure 8 3 j Pull on starter rope to make certain that pawls work properly When starter rope is pulled pawls should pivot to engage flywheel ratchet releasing pawls should retract to starting posi tions k Attach manual starter assembly to fan housing with 3 screws STARTER ROPE REPLACEMENT Remove starter assembly Pull starter handle until rope is fully unwound Lock starter pulley in position by aligning holes in housing and pulley and inserting a nail or pin through them Untie knot and remove rope from rope handle Remove rope from starter assembly Cut new starter rope to length of 73 3 4 inches Fuse ends of rope over open flame for about one half inch Rope end must be stiff to holdin pulley Tie knot in end of rope and thread through pulley and housing See Figure 8 3 Remove locking pin and allow starter to rewind Replace starter assembly Replace starter handle SECTION 9 ENGINE TABLE OF CONTENTS DEBCIGPXIUN 44529 705 Pur ave waa fans 9 2
32. to chain case with six screws and lock washers Install secondary sheave on input side as described under SEC ONDARY DRIVE Figure 10 16 AS REQUIRED Figure 10 17 10 9 10 10 REVERSING TRANSMISSION LINKAGE ADJUSTMENT DESCRIPTION An over center type linkage is used to operate the reversing mech anism This linkage when correctly adjusted provides an effect which locks the transmission firmly in the selected output rotation until the dash panel lever is moved ADJUSTMENT Be sure that the linkage has been correctly assembled See Fig ure 10 18 Loosen or remove dash panel shift control handle so that it will not affect linkage adjustment Loosen lock nut on reverse lock clevis and eyebolt assembly With the transmission in reverse pinion shaft in adjust reverse lock clevis so that the threaded eyebolt touches the pinion shaft link Tighten eyebolt lock nut Check reverse locking by visually check ing center lines of reverse lock clevis and lock plates These centerlines must cross as shown in Figure 10 19 SHIFT CONTROL ROD ADJUSTMENT Assemble control rod thru dash panel Place transmission in forward operating position c Attach end of control rod to linkage See Figure 10 18 Attach assist spring Adjust shift control rod at connector and handle so that forward rod movement is limited at the dash panel by the shift handle locknut Figure 10 18 Check ope
33. too slowly check the battery cables and connections Inspect all wiring connections in the starter circuit to insure that they are clean and tight Proceed with the following tests if additional troubleshooting is necessary STARTER SYSTEM TESTING The following tests fall into two groups starter circuit tests and starter motor tests Starter circuit testing is a quick means of pin pointing causes of hard starting which may result from a faulty electrical component in the starter circuit and can be performed without removing any components from the engine NOTE All starter circuit testing must be done with a fully charged 12 volt battery STARTER CIRCUIT TESTING Starter Motor Amperage Draw Test a Ground spark plug high tension leads so that engine can be cranked without firing Place clamp on DC ammeter capable of reading at least 200 amperes around starter motor lead see Figure 7 36 b Turn ignition switch to START and observe amperage reading with engine cranking Current should be between 75 amperes mini mum and 140 amperes maximum after initial surge CAUTION DO NOT operate starter motor for more than thirty seconds at a time without pausing to allow motor to cool for at least two minutes Starter Motor Available Voltage Test a Inspect battery and cables to make sure that battery has ample capacity for cranking NOTE Engine must be at normal operat ing temperature when test is made b Ground spark plug hig
34. up the head on the strap per Figure 6 16 d Tighten head on strap with pliers as illustrated in Figure 6 17 6 7 FUEL RETURN LINE AS Figure 6 17 7 1 SECTION 7 IGNITION AND ELECTRICAL SYSTEMS TABLE OF CONTENTS DESCRIPTION 1 2 TEST EQUIPMENT 1 2 MAGNETO 1 3 REMOVAL 1 3 TESTING 1 5 gt 499 BREAKER POINTS ame 4 1 5 CONDENSER aa 1 5 MAGNETO DRIVE COILS 7 6 IGNITION COILS 1 6 HIGH TENSION LEADS THT 5 Pj SPARK PLUGS 7 8 BATTERY aes 7 9 DESCRIPTION 1 9 SPECIFICATIONS 140 INSTALLATION 1 10 BATTERY SERVICING cia BATTERY 1 11 BATTERY TESTING BATTERY CHARGING 7 12 SLOW CHARGING sasa A WARRANTY le Kegs wes 7 12 STARTER SYSTEM 1 12 DESCRIPTION 1 12 MAINTENANCE pva 1 13 STARTER SYSTEM T STING 1 13 STARTER CIRCUIT TESTING 17 13 STARTER MOTOR TESTING T 14 INSPECTION OF STARTER MOTOR
35. wrench on outside loosen end cap bolt See Figure 10 3 _ CAUT ION Primary sheave is spring loaded Clamp primary sheaves to gether with strap Service Tool No 261906 before proceeding with disassembly See Figure 10 4 Remove end cap assembly See Figure 10 4 f Remove strap while pressing movable half of sheave toward engine g Remove sliding sheave and inspect main shaft spline neutral lock out balls bearing compression spring and garter activating spring see Figure 10 5 CLEANING INSPECTION AND REPAIR a Clean all parts with a cleaning solvent such as Trichloroethylene see SAFETY PRECAUTION page 9 6 and blow dry with com pressed air b Inspect main shaft and sheave assembly splines for wear c Inspect neutral lockout plunger for wear Replace if required 10 3 3 SHEAVE A GAD a AND HUB 8 NEUTRAL LOCKOUT BALL END CAP ASSEMBLY PRIMARY DISC MAIN _ SHAFT PRIMARY SPRING END BOLT PLUNGER AND ROD ASSEMBLY ACTIVATING SPRING SLIDING SHEAVE HUB SLIDING PRIMARY SHEAVE SPRING 7507 Figure 10 5 d Inspect transmission belt A glazed or burned belt or one meas uring less than 1 9 16 across width or outer surface must be placed with a new one Worn belt should be returned to owner for use asa spare spare belt should be carried at all times REASSEMBLY BALL 2 1 Align hole
36. 1 6 Lubricate of left front bearing with A to help seat O ring Assemble front axle as sembly to chassis Fasten flangettes to chain case and chassis Torque six screws flangettes to chain case and flangettes to chassis 20 25 ft lbs Axle must be free to slide through the bearings d Assemble spacer sprocket and retaining ring to left end of axle Pull axle to right of vehicle to take up all clearance between the Spacer sprocket retaining ring and bearing e Lock bearing collars Rotate in the direction of axle rotation for ward gear Use a pin punch and hammer to make sure collar is tight f Apply Loctite grade A to set screws for locking collars Torque both set screws collars to axle to 25 35 in lbs g Axle assembly must be free to rotate after assembly to chassis REAR AXLE ASSEMBLY a For sequence of assembly of sprockets bearings pivot arms and brackets refer to Figure 11 6 b Lubricate the outside of the bushing and outside of pivot arm about 1 2 inch radius around pivot hole with Rykon grease No 2EP 11 7 Apply Loctite grade A to the set screws for sprockets or wheels prior to assembly Torque set screws to 18 20 ft lbs d Torque rear axle pivot nuts to 12 15 ft lbs Axle must rotate freely when assembled to chassis Pivot arms must rotate on bushings with no binding or other restriction IDLER ASSEMBLY a Assemble idler wheels to shaft with retaining r
37. 17177 Figure 1 44 BELT TENSION a Correct starter motor drive belt tension is extremely important loose belt will cause slippage and a tight belt will result in a ruined starter when it is driven overspeed by the engine after starting See Page 7 12 b Install starter belt between starter and flywheel pulleys c Turn movable half of pulley counterclockwise to drive position See Figure 7 44 d Move starter down to tighten belt Be certain that pulley halves are CLOSED or in driving position when making the adjustment Belt must be free when pulley is turned fully clockwise engine run position ALTERNATOR TROUBLE SHOOTING Failure in the alternator charging circuit will usually show up when the head and taillights do not function or when the battery fails to retain a charge sufficient to start the engine consistently To determine the cause of trouble check the condition of the battery and electrical con nections throughout the circuit before proceeding with electrical testing A visual inspection may be all that is required to locate the trouble Disconnect battery leads before tightening or changing any con nections a Battery Check condition as described under Battery Testing Battery Inspection and Battery Care b Wiring The importance of connections which are good electrically and mechanically throughout the circuit cannot be overemphasized The largest percentage of electrical system failures are ca
38. CK WASHER Figure 10 12 Adjust brake and control lever as described under ADJUST MENT When brake is off pucks should not drag on brake disc SECONDARY DRIVE DISASSEMBLY a Remove transmission belt see Section 9 See Figure 10 13 b Remove brake assembly 2 screws Remove screw tab lockwasher secondary washer spring cap d Slide movable sheave fixed sheave and brake disc assembly from spring and sleeve transmission input shait Cast aluminum sheaves DO NOT strike sheaves with hammer See will bend CLEANING AND INSPECTION 1 Clean all parts except movable sheave bushing in trichlorethylene Bushing is oil impregnated DO NOT clean with solvent SAFETY PRECAUTION on part 9 6 2 Check bushing for wear 3 Check shaft sheaves woodruff keys and Delrin ramp shoes for Check sleeves for burrs and nicks excessive wear a Lubricate movable sheave bushing with Rykon 2 EP Use a small RE ASSEMBLY amount 0 3 in groove in bushing CHAIN COVER CHAIN OIL FILL PLUG SEAL OUTPUT SHAFT SHIFTER DOG SPRING SHIFTER IDLER BASE AND SHAFT i RING CHAIN CASE OUTPUT SUPPORT BRACKET CRADLE NEEDLE BEARING THRUST 2 s WASHERS 38 A SHIM 6 a j Y TRANSMISSION z HOUSING CLEVIS cg
39. ENSION LEADS Spark plug high tension leads may be tested for leakage or insulation failures by using the ignition analyzer and an ignition coil see Figure 7 19 Connect the coil to the ignition analyzer as for the coil test Connect a separate test lead with suitable clips to the secondary term inal entir of the coil and to the conductor of the spark plug lead Probe the insulated surface of the spark plug lead with the grounded test probe Arcing will be apparant wherever the insulation has broken down due to moisture or carbon trails REASSEMBLY a Install magneto drive coils making certain that coil laminations are flush with bosses on magneto plate see Figure 7 20 Install breaker assembly over breaker post Install condenser Connect magneto drive coil lead condenser lead and lead from electrical panel assembly to breaker point screw terminal Install new oiler clip and wick in position on mounting boss see Figure 7 21 Apply Delco U 1901 1948792 distributor lubricant to oiler wick and to point cam follower on side toward cam rota tion Install cam on crankshaft over Woodruff key and rotate to position shown in Figure 7 21 Adjust breaker points using a feeler gage and with the breaker cam and key installed on the crankshaft see Figure 7 21 Point gap should be set to 020 022 inch with the breaker arm on the high lobe of the cam full open Rotate crankshaft so that crankshaft
40. EVEN THOUGH BRAND OUTBOARD LUBRICANT IS ADVERTIZED AS A 50 1 RATIO LUBRICANT IT IS IMPERATIVE FOR SNOWMOBILE USE THAT IT BE MIXED AT 24 1 GAS LUBRICANT RATIO The use of higher priced premium gasolines is not recommended the compression ratio of the engine is not high enough to warrant the use of such fuel addition the lead and other additives which are used to increase the octane rating of premium gasolines or otherwise improve performance may shorten spark plug life The use of additive compounds such as tune up compounds tonics friction reducing compounds etc is discouraged Accessories Engine Cleaner and OMC Accessories Break In Lubricant should be used as necessary according to instructions OMC 244 FUEL CONDITIONER OMC 244 Fuel Conditioner is recommended for added protection to your snowmobile engine It is especially recommended as an additive between extended periods of snowmobile use 244 Fuel Condi tioner is available from your dealer OMC 244 Fuel Conditioner features are as follows Fuel Stabilizer prevents formation of gum and varnish deposits in fuel system for one year of storage Eliminates need for draining fuel for storage Carburetor Cleaner dissolves gum and varnish deposits in carbu retor and fuel system Corrosion Resistance protects carburetor fuel system and in ternal engine parts from corrosion De icer prevents carburetor icing and gas line freeze
41. Fill tank with fresh fuel mixture Install battery Tune up engine see Section 5 Lubricate all points as described under Lubrication Adjust track for proper tension and check track alignment see Section 11 Align skis see Section 11 Check brake and throttle control adjustments Tighten all screws and nuts Clean inner surfaces of primary and secondary sheave halves of oil and grease Replace transmission belt Test vehicle checking particularly the following items 1 Function of neutral lockout 2 Function of brake 3 Engine performance Thoroughly clean any surfaces that need refinishing and touch up 12 5 FUEL INLET ELBOW Figure 12 7 a LI E a a 4 a a a s i LI s b 4 d L 5 an gt t the a a ON va z gt T7 i E fa 4 E a 4n T pa 1 5 T e i hon t NOTES CT M NOTES e fT temm A ee qvae ot ce oi E A pet Cete k t 2 2 3 P 4 ad
42. Follow operating instructions furnished with armature growler for proper test procedures Clean between commutator segments of armature and recheck armature on growler shorted turns are still indicated replace armature Check armature for grounded windings see Figure 7 42 Rotate one lead of continuity tester test light or meter around circum ference of commutator while holding other continuity meter lead on the armature core or shaft An indication of continuity means that the armature windings are grounded and armature must be re placed Check armature for open windings by using an ohmmeter ure resistance between adjacent commutator segments using LO OHMS scale Rotate leads around entire circumference of com mutator An open winding is indicated if any one reading is much higher three times higher or more than the average reading Inspect commutator segments If they are dirty or show signs of wear turn commutator in a lathe until surface is clean and smooth After turning commutator undercut insulation between commutator segments to a depth of approximately 1 32 inch The undercut must be flat at the bottom triangular groove cuts are unsatisfac tory and should extend beyond the brush contact area for the full length of each insulated groove see Figure 7 43 After commutator has been undercut sand lightly with No 00 sand paper to remove burrs left during the undercutting process After sanding clean
43. Measure distance from bracket to anchor on each side Figure 11 3 dimension A If measurements are not equal loosen adjustment on the side with longest dimension until measurement is equal within 1 32 This is done by turning the pivot arm adjusting screw counterclockwise Tighten all re taining nuts TRACK ALIGNMENT ADJUSTMENT Proper track alignment is essential to keep rubber sprocket and track wear at a minimum 2 7 8 41 32 ANCHOR PIVOT ARM REAR ADJUSTING SCREW PIvOT SCREW ADJUSTING AXLE NUT TRACK TENSION NUTS BRACKET Figure 11 3 11 4 When aligning track block up snowmobile so that track is off ground and place front edge of skis against stationary object Start engine and run at idle allowing track to turn free The track edges must be clear of pivot arms as shown in Figure 11 4 REMOVAL OF TRUCKS AND TRACK a Support snowmobile so that weight is removed from track b Release pivot axle spring See Figure 11 5 c Remove rear axle pivot bolts Complete rear axle assembly can now be removed d Remove forward truck assembly cross shaft and truck assembly screws Bring truck assembly out of chassis e Remove chain case cover Figure 11 4 f Remove retaining ring sprocket and spacer from end of axle g Loosen set screws from locking collars and rotate collars to free axle from bearings Remove three screws flangette to chain case on left side of vehicle and three screws flang
44. NERAL SNOWMOBILE INFORMATION TABLE OF CONTENTS TWO CYCLE ENGINE OPERATION 3 2 CARBUBETION bas old 3 3 IGNITION 4 44 2 3 3 POWER FLOW Cres 3 4 PRIMARY DRIVE 3 4 NEUTRAL LOCKOUT 3 5 SECONDARY DRIVE 3 5 REVERSE TRANSMISSION 3 5 3 2 POWER STROKE DOWN COMBUSTION OF FUEL AIR MIXTURE ROD BALANCE AXIS OF ROTATION Figure 3 1 FUEL INTAKE AND EXHAUST LEAF VALVES CLOSED INTAKE EXHAUST PORT OPEN Figure 3 2 COMPRESSION STROKE UP LEAF VALVE FUEL FROM INTAKE PORT CLOSED 4 y Node lt 5 PORT CLOSED Figure 3 3 TWO CYCLE ENGINE THEORY An internal combustion engine is one in which fuel is burned inside the engine a charge of fuel is introduced into a combustion chamber cylinder within the engine and ignited The energy released by the expansion of the burning fuel is converted to torque by the piston con necting rod and crankshaft Internal combustion engines are classified as either four cycle or two eycle engines The four and the two refers to the number of piston strokes required to complete a power cycle of intake compres sion power and exhaust piston stroke is piston travel one direc tion only up is one stroke down is another In a four cycle engine
45. TARTER Manual starter pulls out but starter does not engage flywheel a Friction spring bent or burred b Excessorincorrectgrease onpawlsor Spring c Pawls bent or burred d Pawls frozen water in place Starter rope does not return a Recoil spring broken or binding b Starter housing bent 3 c Loose or missing parts Clattering manual starter a Friction spring bent or burred b Starter housing bent c Excess or incorrect grease on pawls or spring 4 Dry starter spindle STARTING ELECTRIC STARTER 1 Starter cranks too slowly a Weak battery b Loose or corroded connections Faulty starter solenoid or solenoid wiring Worn brushes or spring e Faulty field or armature shorted or open windings Starter will not crank motor a Faulty ignition key switch b Faulty starter solenoid or solenoid wiring Broken wire in harness or connector d Weak battery Loose or corroded connections Moisture in starter motor Broken or worn brushes or broken brush spring Faulty field or armature shorted or open windings RUNNING LOW SPEED ONLY 1 Low speed miss a Incorrect gas lubricant ratio b Carburetor idle adjustment too lean or too rich Leaf valve standing open or preloaded shut Spark plugs improperly gapped dirty or broken e Loose or broken ignition wires f Spark plug terminal loose g Weak coil or condenser h Breaker poin
46. Whenever it is necessary to mix fuel and lubricant at temperature below 32 F 0 C the lubricant should be prediluted with gasoline to improve its mixability The lubricant should be prediluted with ap proximately one part gasoline to one part lubricant Predilution of the lubricant should take place with the lubricant temperature above 32 Do not use kerosene or fuel oils for pre mixing NOTE Thorough agitation is required to completely mix or blend the fuel the lubricant adheres to the bottom and sidewalls of the container unless agitated Simply pouring the gasoline onto the lubricant CANNOT accomplish thorough mixing LUBRICATION RECOMMENDATIONS MAIN TENANCE LUBRICANT After 25 hrs Ski Pivots Leaf spring connections to skis SAE 10 Oil Required Standard Oil Rykon EP 2 Annually Rear Axle pivot bushings J Removal Standard Oil Rykon 2 Annually Truck Axles Annually Drive Chain oil bath See page 10 4 OMC Type C Annually Reversing Transmission See page 10 9 OMC Type C Annually Normal Use Primary Drive Disassembly Required See your Dealer Standard Oil Rykon 2 Semi Annually Extended Use Specified lubricants available from your dealer 12 4 AIR CLEANER SCREENS HOUSING Figure 12 6 PREVENTIVE MAINTENANCE MAINTENANCE After first 3 hrs then every Adjust Chain Tension 25 hrs as required See Page 10 4 After first 10 hrs then every Adjust Track Tension 25 hrs
47. ard of the jets to restrict the flow of air When the choke shutter is closed more gas oline and less air is allowed into the air stream resulting in a richer fuel air mixture When normal operating temperature is reached the choke is opened and the standard ratio of gasoline and air allowed to flow from the carburetor IGNITION The ignition system provides a high voltage electric current which causes a spark to jump the spark plug gap within the cylinder and thus ignite the compressed fuel air mixture in the cylinder The ignition system consists of the magneto drive coils breaker points and con denser and the ignition coil assemblies Permanent magnets built into the flywheel revolve around the magneto drive coils As the magnet moves past the coils the direction of the magnetic flux through the coil is changed from one direction to the other see Figure 3 6 Self inductance of the magneto drive coil circuit completed through the breaker points prevents the flux in the coil laminations from changing until the breaker points open When the points open the flux changes direction very rapidly inducing a current which flows through the ignition coils primary windings The ignition coils transfrom this cur rent to a very high voltage which is sufficient to discharge across the spark plugs gap The lighting system coils produce alternating current which changes in frequency and voltage in proportion to the engine speed models
48. be changed at any time without notice and without obligation towards vehicles previously manufactured TORQUE SPECIFICATIONS APPLICATION Nut Ball Joint to Steering Arm and Steering Column 18 20 Nut Cable to Solenoid Screw Coil Clamp to Main Frame Screw Connecting Rod 29 31 Screw Crankcase 5 7 Nut Cylinder to Crankcase 16 20 Screw Engine to Engine Frame Assembly 3 8 16 18 20 Nut Exhaust Manifold to Cylinder 5 16 24 10 12 Screw Flangettes to Frame 3 8 16 20 25 Nut Flywheel 40 45 Screw Engine Frame to Main Frame 3 8 16 18 20 Nut Front and Rear Truck Axles 5 8 18 50 60 Screw Axle to Frame 3 8 16 20 25 Setscrew Locking Collar 110 32 Bolt and Rear Axle Pivot Nut 5 16 24 12 15 Setscrew Rear Sprocket 3 8 16 18 20 Nut Rear Suspension to Frame 5 16 24 12 15 Nut Runner to Ski 5 16 18 Nut U Bolt to Saddle 10 12 Spark Plug 20 20 1 2 Nut Throttle Cable Adjusting Screw 5 16 18 Nut Tie Rod 3 8 24 18 20 Screw Truck to Frame 3 8 16 25 30 Screw Truck to Frame 7 16 14 25 30 Screw Secondary End Cap to Shaft 3 8 16 22 25 Screw Drive Sprocket 1 4 20 15 17 Screw Shifter Clevis to Pinion Shaft 1 4 28 Screw Bolt Screw Screw B 15 22 Screw 25 35 Screw 35 40 Screw 60 80 Screw 120 140 Screw 220 240 Specifications and features may be changed at any time without notice and without obligation towards vehicles previously manufactured Use Torque Wrench SECTION 3 GE
49. broken down into three steps 1 Identifying the problem 2 Determining the cause of the problem and 3 Carrecting the problem Familiarity with the factors which affect two cycle engine perform ance is important in making a correct service diagnosis Factors which affect engine performance include the quality of the fuel and fuel mix tures compression spark and spark plug operation and proper drive system adjustment This section discusses compression and spark plugs and their relation to performance A complete discussion of fuel mixtures is included in Section 12 Familiarity with factors which con tribute to abnormal performance of an engine are similarly helpful The skiled mechanic s experience is a great asset here The Trouble Check Chart at the end of this section will assist in tracing symptoms of trouble to the source COMPRESSION The pistons and piston rings perform two functions They compress the mixture of fuel and air in the cylinders before ignition and receive the force of the power after ignition For maximum compression the cylinder must be round and the piston and piston rings correctly fitted to it The rings must be properly seated in the ring grooves and free expand against the walls of the cylinder rings will not retain the force of combustion if the pistons and cylinder walls are excessively worn scored or otherwise damaged or if the rings become stuck in grooves because of carbon accumulation
50. burn when mixed with air ina proportion from 12 1 to 18 1 by weight Mixtures of different proportions are required for different purposes Idling requires a relatively rich mixture leaner mixture is desirable for maximum economy under normal load conditions avoid lean mixtures for high speed operation The carbure tor is designed to deliver the correct proportion of fuel and air to the engine for these various conditions The carburetor is essentially a simple metering device The float chamber holds a limited quantity of fuel regulated by a float valve Needle valves permit a precise amount of fuel to flow from the float chamber to the carburetor throat The upstroke of the piston creates a suction which draws air through the leaf valves and the carburetor throat At a particular point the throat is restricted by a venturi see Figure 3 5 The venturi has the effect of reducing air pressure in the air stream creating a partial vacuum which draws fuel from the jet nozzles As it is rushed along to the firing chamber the fuel is swirled about in the air stream and vaporized A shutter or butterfly valve in the throat regulates the amount of air drawn through the carburetor To vary the speed of the engine the throttle shutter opens or closes regulating the amount of fuel air ture drawn into the engine A richer fuel mixture is required for starting a cold engine A sec ond shutter called a choke is placed into the throat forw
51. castellated brake adjustment nut See Figure 10 12 b Remove cotter pin and washer from brake control pivot pin Com press brake return spring and remove pivot pin from control cable c Remove brake bracket to transmission screws REPAIR SECONDARY a Disassemble brake assembly as required noting relative positions SHEAVE of components to assure correct reassembly see Figure 10 12 b Inspect brake pucks the free floating puck is one half of its Figure 10 11 original 1 2 thickness it should be replaced When the fixed puck is worn so that there is only 1 32 protruding from the carrier it should be replaced Use a contact cement to secure new puck to carrier CAUTION Keep all oil and grease from puck surfaces BRAKE CABLE CAM ASSEMBLY a Reassemble the brake and bracket assembly Locknuts 2 on screws retaining the puck bodies must be tight b Secure brake bracket screws to transmission c Assemble brake control cable lockwasher and nut to brake bracket See Figure 10 12 d Install return spring and pivot pin on control cable Insert pivot pin into brake cam arm and secure with washer and cotter pin 10 6 j E n _ 4 wx um 74 LOCK NUT a ZDAR HS v 1 i CASTE LLATED T N CAM SPRING PIVOT PIN SPACERS CAM LIMIT PIN CARRIER SIDE BODY 1 24 BRAKE BRAKE BACK UP PU
52. cross which the high voltage from the ignition coil can be discharged The resulting spark ignites the compressed mixture of fuel vapor and air in the cylinder See Figure 4 1 Spark plugs are made in a number of heat ranges to satisfy a variety of operating conditions The heat range of a spark plug refers to its ability to dissipate heat from its firing end to the cylinder head The heat range established for any spark plug is determined in design by the length of the path which the heat from the tip must travel to the thread and seat area where it is transferred to the cylinder Spark plugs having a short gap between the firing end of the center electrode and the thread and seat area are used for hot running engines see Figure 4 2 Snowmobiles used in heavy load conditions ie deep snow or sled towing will run the engine temperature higher and in this case a colder plug might be recommended Spark plugs operating under these conditions must remain cool enough to avoid preignition and excessive erosion Spark plugs having a long gap transfer heat slower and are used on cooler running engines See Figure 4 3 Cooler running en gines have a relatively low combustion chamber temperature therefore a high spark plug temperature must be sustained in order to burn off normal combustion deposits and avoid fouling For most effective sparking through any rpm range and under all conditions of operation the electrode and insulator tip temperatur
53. cwi 5 2 COMPRESSION 2 5 2 2 5 2 NEW VEHICLE DELIVERY 5 3 TUNE UP PROCEDURES 5 5222 222 5 3 IGNITION TIMING ADJUSTMENT 2 9 COMPRESSION RELEASE VALVE ADIJUSINMIENT www Yo 2 0 CARBURETOR ADJUSTMENTS 5 5 HIGH SPEED NEEDLE VALVE 5 5 LOW SPEED NEEDLE VALVE 2 6 IDLE ADJUSTMENT SCREW 5 6 cc UR 5 6 5 2 WORN RING GROOVES WARPED RING INSUFFICIENT GAP CARBONED RING AND GROOVE WORN RING ROUNDED EDGE SERVICEABLE RING SQUARE EDGE Figure 5 1 DESCRIPTION The purpose of tune up is to restore power and performance which have been lost through wear or deterioration of one or more parts of the snow machine The successful completion of a tune up depends on an understanding of principles of two cycle engine operation and a fa miliarity with factors affecting performance This section gives com plete tune up procedures Refer to Section 3 for principles of operation and to Section 4 for trouble shooting procedures Lubrication proce dures and instructions for storage are included in Section 12 FACTORS AFFECTING PERFORMANCE In the normal operation of an engine the operator may not be fully aware of the decrease in performance which takes place slowly over a long period of time Economical trouble free operation can best be assured if a complete tune up is performed at least once each year preferab
54. e See Figure 9 3 Disconnect throttle cable at carburetor Loosen jam nut and turn out on throttle cable fitting Pull cable through intake manifold See Figure 9 4 Disconnect choke cable from choke lever arm at carburetor Loosen set screw then pull cable through projection on carburetor See Figure 9 4 Remove two screws securing brake caliper to secondary See Figure 9 5 Disconnect fuel lines and pulse line from fuel pump carburetor and fuel tank Remove shift handle from reverse operating rod Remove neutral lockout cable from bracket See Figure 9 5 Disconnect compression relief cable from compression relief valve See Figure 9 6 1 Disconnect cigarette lighter and engine electrical connector move connector to ignition light switch m Disconnect cables from speedometer and tachometer heads if these accessories are on snowmobile n Remove three screws from lower steering column flange Remove two screws holding steering column yoke and rubber bushing See Figure 9 7 Remove steering column assembly o Disconnect fuel lines from bottom of primer Remove two bolts securing primer to chassis p Grasp starter rope just behind starter and pull all the way out Tie knot in rope Remove knot in starter grip and pull rope through instrument panel Remove manual starter assembly q Remove one screw from instrument panel to chassis bracket on each side of snowmobile Remove three screws from rear of instrument
55. e hand operated ORE SSG owes Sop ee wae oe ge Thumb operated Track ceed Specially designed fully adjustable Width ata ewan wae ead se ZU BEES Lass Formed steel equipped with shock absorbing leaf Springs and replaceable wear runners Seating capacity Two adults Vinyl coated cover molded urethane foam cushion Hood a 4 MOlded polycarbonate Lighting Retractable sealed beam headlight and taillight Fuel tank Capacity 5 Imperial gallons 6 U S gallons Lubrication 24 1 using Johnson Skee Horse Lubricant or SAE 30 SB or SD oil Carburetor Needle Adjustment High speed ieee eee turn off seat minimum Low speed 725 5 1 1 4 turn off seat RPM Ratings peeve ron E 9 aoe 1300 1600 Transmission belt engaging speed Approx 2700 Maximum RPM at which neutral lockout s s ada maa 4 Approx 2000 Ignition Breaker point aap eee 10 027 Mark Champion JTJ or equivalent SpArE Pil gat es 028 033 inch Condenser capacity baa
56. e halves in bearing area to approximately 450 F Tap crankcase with rawhide mallet to break seal and separate crankcase halves Pistons connecting rods and caps are matched parts Because this it is essential to maintain their original positions at reassembly Mark each connecting rod and cap piston and bearing component to assure correct mating during reassembly Also mark the cylinders and crankcase halves from which they are removed 9 5 HOLE PLUG CYLINDER AND STUD ASSEMBLY COMPRESSION E GASKETS COMPRESSION RELIEF VALVE Sy 20 il EXHAUST CRANKCASE MANIFOLD ASSEMBLY EXHAUST MANIFOLD CONNECTING ROD SCREW CRANKSHAFT CONNECTING ROD CAP G re Jj senne GASKETS ASSEMBLY CONNECTING ROD PISTON BEARING RETAINER BEARING Ce NEEDLE ie 2 i fi BEARING ASSEMBLY gt ROLL PIN 7 WRIST br BOTTOM GASKET PISTON RING SET Figure 9 10 9 6 RETAINING Remove connecting rod caps Remove connecting rods from crank e ING shaft Reinstall matched caps on connecting rods m Remove rings from pistons DO NOT try to save the rings Install a complete set of new rings on every overhaul n If necessary to remove connecting rods from pistons remove wrist pin retaining rings using Truarc No 1 pliers Service Tool 303857 see Figure 9 11 Press out wrist pin to free pis
57. e must be kept high enough to vaporize or burn off particles of fuel mixture which collect on the insulator Low plug temperatures result in electrode fouling by an accumulation of unburned fuel particles carbon bits sludge etc Se lection of the correct spark plugs for an engine depends on the type of service to which it will be subjected A cold running engine will require a hot plug and a hot running engine a cold plug Spark plug recom mended for use on the Ski Horse snowmobile is the Champion J7J or equivalent See page 7 8 for additional information on spark plugs 4 3 GROUND ELECTRODE CENTER ELECTRODE INSULATOR Figure 4 1 gt SHORT GAP COOL PLUG Figure 4 2 LONG GAP HOT PLUG Figure 4 3 TROUBLE SHOOTING PROCEDURES Trouble shooting to determine the cause of any operating problem may be broken down into the following steps a Obtaining an accurate description of the trouble b Quick tune up e Use of Trouble Check Chart to analyze engine performance An accurate description of the trouble is essential for trouble shooting The owner s comments may provide valuable information which will serve as a clue to the cause of the problem Find out pertinent facts sueh as Correct spark plugs b Throttle linkage properly adjusted c Tank filled with fresh elean fuel of the proper mixture d Spark at each spark plug Carburetor adjusted correctly 1 Compression Turn
58. e page 6 2 Adjust throttle cable so that carburetor butterfly valve isfull open when thumb throttle lever touches handle grip Figure 6 8 When the lever on the carburetor is returned to the idle posi tion there must be 1 32 minimum over travel in hand lever Slot in throttle lever must align with slot in cable support bracket Torque nut on cable adjusting screw to 60 80 inch pounds l A carefully rebuilt HD model carburetor should perform well The two most likely causes of carburetor failure are dirt and a care less repair job m See page 5 5 for needle valve adjustment procedure LEAF VALVES a Separate the intake manifold from the crankcase body removing the gasket and leaf plate and base assembly b Rinse leaf valves and leaf valve body in cleaning solvent and blow dry with light air pressure to prevent leaf damage Inspect the leaf valve assembly and disassemble if necessary see Figure 6 9 Special caution is necessary in disassembling the leaf valve assembly DO NOT damage or interchange the leaves a The leaves must be flat to maintain a seal with the leaf valve body DO NOT under any circumstances bend or flex the leaves by hand DOW gt Carburetor Gasket Flange Gasket Throttle Shutter Carburetor Body Throttle Shaft Clip Return Line Elbow Return Line Screen Idle Speed Bracket Bracket Screw Throttle Shaft Return Spring Throttle Shaft Sleeve Idle
59. ease actuator with Rykon EP 2 grease CARBURETOR ADJUSTMENTS HIGH SPEED NEEDLE VALVE CAUTION LEANING OUT OF THE HIGH SPEED NEEDLE VALVE WILL RESULT IN SERIOUS DAMAGE TO THE ENGINE NEVER SET THE HIGH SPEED NEEDLE LESS THAN ONE TURN OPEN For average use the engine will operate satisfactorily with the car buretor adjusted as it left the factory If it becomes necessary to read just due to altitude or climatic conditions follow these instructions carefully COMPRESSION RELEASE VALVE p 1 32 TO 1 16 Figure 5 2 COMPRESSION RELEASE d ADJUSTMENT S um Figure 5 3 5 6 HIGH SPEED NEEDLE VALVE ADJUSTMENT HIGH SPEED NEEDLE VALVE ADJUSTMENT WHEEL ADJUSTING HIGH SPEED NEEDLE VALVE ON REAR OF CARBURETOR Figure 5 4 IDLE ADJUSTMENT LOW SPEED NEEDLE VALVE A PULL COVER STRAIGHT OFF WITH SLIGHT TWIST Figure 5 7 The correct high speed needle valve setting is obtained by 1 Blocking up the rear of the vehicle to free track 2 Pre set high speed needle approximately 1 turn open 3 Start and warm up engine with drive in neutral Do not over speed engine when warming up in neutral 4 Engage the neutral lockout and run engine at full throttle and turn needle valve counterclockwise permitting the engine to run rich to the point at which it begins to 4 cycle load up See Figure 5 4 5 Turn needle valve back clockwise gradually until
60. ecessary for the experienced service man to reread discussions of theory along with specific service in formation Illustrations placed in the margins provide unimpeded reading of explanatory text and permit close relationship between illustration and text Read this manual carefully to become thoroughly familiar with the procedures described then keep it readily available in the service shop for use as a reference If properly used it will enable the serviceman to give better service to the snowmobile owner and thereby build and maintain a reputation for reliable service This service manual covers all phases of servicing the snowmobile however new service situations sometimes arise If a service question does not appear to be answered in this manual you are invited to write to the Service Department for additional help Always be sure to give complete information including model number and vehicle serial number All information illustrations and specifications contained in this literature are based on the product information available at the time of publication The right is reserved to make changes at any time without notice Instrument Panel Door Speedometer Odometer Neutral Lockout Accessory Reverse Control Throttle Headlight Retracting Lever Primer Hand Brake and Parking Ignition Lights Switch Lock Manual Starter Tachometer Accessory Handle Choke Lighter Electric Start Fuel Level Gauge Models Compression Release
61. eck for water in fuel Rectify problems and change spark plugs Check ignition primary Check spark plugs Check coil and condenser these sometimes break down when they become warm Check points and timing Run engine with air intake housing off If carburetor blows excessive fuel back out venturi pull leaf valve assembly and check for cracked broken or badly seated leaves Clogged vents in fuel tank cap will cause a vacuum in fuel system resulting in vaporizing of fuel in fuel pump See No Ignition High Tension See Section 6 Fuel System Clean vents in gas cap Check high tension leads Terminal might have pulled loose from wire If high tension loss is on Section 7 one or two leads or if engine misses or skips NO IGNITION HIGH NOTE TENSION When checking coil be sure to use probe around coil tower area Coil high tension lead and terminal Coil See Section 7 If you have not yet found Check back into Engine Runs trouble Rough Check flywheel magnet polarity and strength during ignition system examination Most ignition failures are due to malfunctions found in primary system See Section 7 9 1 SECTION 5 TUNE UP PROCEDURES TABLE OF CONTENTS DESCRIPTION riirii ears 452 31 9 2 FACTORS AFFECTING PERFORMANCE 5 2 FUEL SYSTEM 5 2 IGNITION SYSTEM rs Pe eee
62. ed with a filter that should be cleaned during the operating season and at the end of the season for storage clean filter wash with gas lubricant fuel mixture and shake dry If com pressed air is available blow dry from the inside see Figure 6 13 FUEL TANK a For correct fuel and lubricant mixtures and break in instructions see Section 12 b The importance of using a fresh clean fuel mixture cannot be overstressed Gum will form in old fuel which will clog filter screens fuel passages carburetor orifices leaf valves and check valves Remove tank to empty old fuel Reinstall it and begin with a fresh supply every season To disconnect and remove the tank for cleaning remove nuts and bolts from hold down straps snap fuel gauge cap out with screw driver and remove cable Tank can now be lifted out past the heat shield See Figure 6 14 P Clean the tank by pouring some gasoline into the tank through a filtering funnel Shake the tank and contents and empty the con tents through the fillopening Replace cable and in fuel tank Use more gasoline to flush the fuel line opening Then reinstall the tank and hoses e Check to see there are no leaks at fuel hose connections FUEL LINE TIE STRAFP Fuel line tie strap part 262081 must be replaced with a new strap after its removal Assemble the new strap around the fuel line with the serrated side toward the inside See Figure 6 15 Snug
63. een See Figure 12 7 See page 6 7 for replacement of fuel line tie straps STORAGE PREPARATION FOR STORAGE Add one ounce of OMC 244 fuel conditioner to each gallon of gaso line in tank and mix thoroughly Run engine a few minutes until mixture is in fuel lines and carburetor where it can prevent summing of check valves and carburetor jets b Wash machine Be certain to hose out undercarriage Clean seat ing with automotive foam type upholstery cleaner 1 1 Treat engine with Accessories Engine Cleaner Remove fuel pump filter screen and clean See Page 12 4 Run engine with neutral lockout knob pulled out and inject OMC Rust Preventative Oil with oil can rapidly into carburetor until engine stops Turn off ignition and replace fuel pump filter screen Clean air filter Wash with gasoline lubricant mixture and shake dry 1f compressed air is available blow dry from the inside See Figures 12 3 and 12 4 Block both ends of unit off ground to take weight off track and skis Loosen track tension see Section 10 Drain and clean fuel tank see Section 6 Provide for proper battery maintenance as described in Section 7 Remove transmission belt Rub bottom of skis and other unprotected surfaces of vehicle with cloth saturated in Rust Preventative Store in dry well ventilated area Clean carburetor fuel filter screen See Page 12 4 REMOVAL FROM STORAGE 1
64. emove weight from skis IMPORTANT Mark ski column and steering arm with center punch as shown in Figure 11 1 Marking is required to assure correct steering geometry on reassembly BALL JOINT b Remove ski and leaf spring assembly Disassemble leaf spring if required for servicing Remove steering arm from ski column See Figure 11 2 Figure 11 1 d Remove ski columns CLEANING INSPECTION AND REPAIR Remove all dirt and old grease from ski columns and from inside ski column brackets b Inspect steering column bushing and replace if worn See Figure 11 2 Inspect ski column upper and lower rubber mounts and bushing for wear damage or deterioration d Inspect ski runners and replace if worn e Inspect leaf springs for cracks or weakness STEERING ARM PN JAM NUTS SPRING PEE BALL JOINT WASHER 9 WASHERS 9 pm SKI STOP SKI COLUMN LOCKWASHER 4 1 BUSHING Figure 11 2 REASSEMBLY a Reassemble skis spring and columns if these were disassem bled Refer to Section 2 for Torque b Lubricate ski columns with Rykon 2 grease Place ski and column assemblies in position in frame assembly NOTE DO NOT interchange right and left ski columns Attach steering arms to ski columns using punch marks to obtain original position Tighten to torque value shown in Section 2 Adjust ski alignment as described below SKI ALIGNMENT Ski
65. engine stops 4 cycling and smooths out certain to give the engine time to respond See Figure 5 4 TO MAINTAIN ADEQUATE CYLINDER LUBRICATION THE HIGH SPEED NEEDLE VALVE SHOULD NEVER BE LESS THAN ONE TURN OPEN LOW SPEED NEEDLE VALVE The low speed adjustment should be pre set 1 turn open Final ad justment should be made to engine as necessary See Figure 5 5 IDLE ADJUSTMENT SCREW The Idle Adjustment Screw Figure 5 5 when turned to the right or clockwise will increase the engine idle speed Recommended idle speed is 1300 to 1600 rpm NOTE This adjustment must be made with the neutral lockout knob out or in the neutral position and engine warm ES E F 2 Operating above recommended idle rpm can result in neutral lockout not operating If it is necessary to idle at above recom mended rpm check operation of neutral lockout to insure it is functioning properly See page 3 4 SPARK PLUGS Using the correct spark plug is most important for efficient operation The recommended spark plug for your engine is Champion J7J or equivalent The proper spark plug gap is 028 033 Remove rubber covered spark plug terminal by pulling straight off with a slight twist see Figure 5 6 Remove spark plugs for inspection or replacement as necessary When reinstalling spark plug clean the spark plug seat in cylinder head Be sure spark plug gasket is in place and tighten plu
66. eplace the faulty parts i Remove any worn choke or throttle shafts before cleaning Leave unworn shafts in and clean the whole assembly Mark the throttle 3 and choke 16 shutters before removing them so that they can be reassembled correctly The edges are tapered for exact fit into the carburetor bores Remove two screws and pull the shutter out of the carburetor body Remove the throttle shaft clip 5 and pull the shaft out of the casting Examine the shaft and the body bearings for wear If the shaft shows excessive wear replace it If the body bearing areas are worn replace the body casting Remove the choke shaft 33 from the body carefully so that the friction ball 17 and spring 18 will not fly out of thecasting Inspect the shaft and bushings j Clean all parts before reassembly in a good carburetor solvent Clean a slightly dirty carburetor with compressed air Carefully blow out each channel and orifice in the casting k Assemble the carburetor Keep all parts clean before assembly to the body casting 1 Tighten the inlet seat to 40 50 inch pounds of torque 2 Adjust the inlet control lever so that the center of the lever that contacts the metering diaphragm is flush to the metering cham ber wall see Figure 6 6 3 Install new welch plugs at the nozzle well and by pass chamber if needed Place the new welch plug into the casting counter bore convex side up and flatten it to a tight fit using a 5 16 inch flat e
67. er cycle Near the top of the piston stroke the compressed fuel air mixture is ignited the piston is driven downward and the power cycle is repeated At full throttle this cycle may be repeated more than five thousand times every minute CARBURETION The system which controls the intake of the fuel air mixture in the two cycle engine consists of a set of leaf valves which serve the same purpose as the intake valves on four cycle engine leaf valves are thin flexible metal strips mounted between the carburetor intake manifold and crankcase When the piston is on the up stroke it creates a partial vacuum in the crankcase Atmospheric pressure forces the leaves away from the body see Figure 3 4 opening the passage between the carburetor and crankcase When the piston is on the down stroke it compresses the crankcase charge forcing the leaves against the passage opening and sealing off the crankcase from the carburetor Since the opening and closing may occur in excess of five thousand times per minute the leaves must be thin and flexible Gasoline its liquid state burns relatively slowly with an even flame However when gasoline is combined with air to form a vapor the mixture becomes highly inflammable and burns with an explosive effect To obtain best results the fuel and air must be correctly pro portioned and thoroughly mixed It is the function of the carburetor to accomplish this Gasoline will
68. erfectly round and unscratched to prevent entry of exhaust gases into crankcase chamber Check BREAK piston size taper and roundness using a micrometer see Figure THIS EDGE 9 16 Check clearance between piston and cylinder before rein stalling piston see Figure 9 17 Check tolerances specifica tion page 2 2 Before installing new piston rings check gap between ends of ring by placing ring in its respective cylinder bore see Figure 9 18 Press ring down in bore slightly with bottom of piston to square it up Discard and replace with new ring if gap is excessive see Section 11 Specifications 4 Check each ring in its respective ring groove for tightness or bind ing by rolling the ring around the piston groove see Figure 9 19 Check for groove side clearance with feeler gage see Figure 9 20 see Section 2 Specifications BEARINGS a All areas where bearings are to be serviced must be free from oil and dirt DO NOT spin ball or roller bearings before they are cleaned Dirt in the races could cause serious damage b Clean bearings while they are still on crankshaft by emersing them in a cleaning solvent and turning outer race of bearing Flush all dirt from around balls and separators Tank should be equipped with a screened false bottom to prevent settlings from being stirred up inthe bearings Agitate bearings frequently until all oil grease and sludge have been loosened and can be flushed Bear
69. ette to chassis on right side of vehicle i Remove front axle from chassis j Remove idler assembly Remove screw and washer from each end of axle FRONT AXLE DISASSEMBLY a Remove bearings and flangettes from axle b Drive out roll pins from track drive sprockets MM MEI tanh Sinan Sot UM MM MM amp U E 17 o 5 Sou 2 nei vis ass tonite iis Nts ME um Inr Figure 11 5 If heat is necessary to remove or reassemble front sprockets or rear axle wheels do not use open flame because of danger of igniting the magnesium metal c Press drive sprockets off front axle after marking position for reassembly REAR AXLE DISASSEMBLY a Remove retaining ring and bearing retainer b Push pivot arm towards wheel c Remove bearings d Loosen Allen set screws and remove wheels from axle TRUCK DISASSEMBLY a Remove nut from each end of front and rear truck axles 9 11 FRONT AXLE AXLE PLUG RING GASKET e p VQ DRIVE SPROCKET FLANGETTE ASSEMBLY IDLER WHEEL OUTER 2 ee TRACK IDLER AXLE CROSS SHAFT ASSEMBLY FRONT AXLE FLANGETTE SPROCKET a 9 WHEELS SF N FRONT AXLE BEARING FRONT TRUCK AXLE WHEEL WE oen BUSHING gt FRONT AXLE CENTER SPACER AXLE CENTER SPACER
70. faces may warp or spring particularly where thin sections are flanges are employed and are subject to temperature changes check for flatness lay a sheet of No 120 emery cloth on a surface plate or piece of plate glass see Figure 9 13 Place part to be surfaced on emery cloth and move slowly back and forth several Figure 9 13 times in a figure 8 motion exerting evenly distributed light pres 9 7 sure Lift part from surface plate to observe results If surface is actually warped or sprung high spots marking contact with lap ping surface will take on a dull polish while low areas will retain their original state To insure flatness over entire surface con tinue surfacing until entire gasket surface has been polished to a dullluster Finish surfacing with No 180 emery cloth PISTONS Carefully remove carbon deposits from piston head Inspect ring grooves for carbon accumulation excessive wear or damage to ring seats Carefully scrape carbon from ring grooves see Figure 9 14 making certain that carbon clinging to bottom and sides of grooves has been thoroughly removed without scratching or other wise damaging the grooves A suitable tool for cleaning ring grooves can be made by breaking a piston ring grinding an angle on the edge and breaking the lower sharp edge to prevent damage to lower ring land see Figure 9 15 b Check pistons for roundness taper excessive skirt wear and scoring Piston skirts must be p
71. ferred to the output gear and shaft in reverse rotation Linkage adjustment is important for proper reverse performance See REVERSING TRANSMISSION LINKAGE ADJUSTMENT for adjust ment information LUBRICATION Use the following procedure to check the oil level in the reversing mechanism See Figure 10 15 1 Remove the oil level plug oil runs out or is up to the threads in the hole the level is satisfactory 2 If oil level is low remove the oil fill plug and slowly pour OMC C oil in this hole until it runs out the lower hole 3 Replace plugs CLUTCH DOG SPROCKET RELEASE SHAFT POSITION ROTATION REVERSED SECONDARY SHEAVE SHAFT PINION GEAR ENGAGED REVERSE OPERATION REVERSE OPERATION Figure 10 15 REMOVAL AND DISASSEMBLY m e Remove secondary drive as described under SECONDARY DRIVE Remove upper chain sprocket and key from output shaft as described under DRIVE CHAIN Remove six transmission to chain case screws and lockwashers See Figure 10 16 Remove transmission housing from chain case Output shaft as sembly can now be removed Remove dog clutch assembly from shifter clevis Remove hex head socket screw from pinion gear shaft See Figure 6 17 The shifter clevis pinion gear pinion bearing thrust wash ers thrust bearing and shims if used can be removed Remove end cap and bearing Remove input shaft and gear The pinion gear shaft and
72. flywheel by hand or with recoil starter If compression is present it ean be felt when turning through one complete revolution of the flywheel If little or no com pression exists in both cylinders engine will spin very easily STARTING 1 Hard to start or won t start a Empty gas tank je Incorrect gas lubricant ratio Old fuel or water or dirt in fuel system d Fuel line improperly connected e Fuel line kinked or severely pinched Engine not primed Clogged fuel line or fuel filter h Clogged check valve Carburetor adjustments too lean speed needle bent or bowed Engine flooded 59 1 1 Leaf valves not functioning properly m Faulty gaskets Spark plugs fouled improperly gapped dirty or broken Loose or broken wire or frayed insulation in electrical system x Sheared flywheel key E Faulty coils r Faulty condenser s Binding in engine t Weak or reversed polarity of flywheel magnets Engine won t crank over a Cylinder wall corrosion b Broken connecting rod crankshaft or drive shaft c Engine improperly assembled after repair Cranks over extremely easily a Spark plug loose b Cylinder or pistons scored c Hole burned in piston head d Rings worn Won t start but kicks back and backtires a Flywheel key sheared b Timing out of adjustment c Leaf valves broken or not seating STARTING MANUAL S
73. fully Do not stretch this spring or change its compression characteristics If in doubt about its condition replace it e Remove the inlet needle 22 Remove the inlet seat assembly using a 3 8 inch thin wall socket Remove the inlet seat gasket f The inlet seat assembly consists of a brass cage and a rubber in sert for the inlet needle seat Assemble the insert into the cage with the molded rim side away from the inlet needle point Some HD carburetors are equipped with a rubber tipped needle a brass inlet seat and a copper gasket The installation instructions below apply to both types of inlet seats The inlet needles and seats are matched and tested for leaks at the factory and the parts must be kept in matched sets When installing the insert cage into the carburetor body use anew gasket Do not force the cage you may strip the threads or distort the insert Use a torque wrench to apply 40 to 50 inch pounds torque The needle and seat assembly must be clean to insure correct performance g Remove and inspect the points of the high speed and idle mixture screws See Figures 6 3 and 6 4 Through misuse either mix ture screw point may be bent extruded from being forced into the casting seat or possible broken off in the casting see Figure 6 5 If either mixture screw is damaged be sure to inspect the casting If the adjustment seats are damaged a new body casting is required Check for clogged inlet and return line sc
74. g securely Recommended torque 20 to 20 1 2 ft lbs See pages 4 3 and 7 8 for additional information on spark plugs TABLE CONTENTS DESCHEKEIOM oars Gi eer a ee FUEL 45 CARBURETOR DISASSEMBLY CLEANING RE PAIR AND REASSEMBLY HD SERIES w w Ww CLEANING INSPECTION AND REPAIR REASSEMBLY FUEL PRIMER AIR BITES OE OD PUBL TANK FUEL LINE TIE STRAPS evn SECTION G FUEL SYSTEM 6 2 6 2 DESCRIPTION The complete fuel system consists of the gas tank assembly and lines the primer assembly the fuel pump and filter assembly the carburetor and the leaf valve assembly This section gives complete service procedures on all components of the fuel system and carburetor adjust ments Principles of carburetion are discussed in Section 3 FUEL FLOW Fuel is drawn from the fuel tank by the fuel pump which is operated by changes in crankcase pressure These changes in crankcase pres sure are transmitted to the fuel pump via the pulse line The filter element removes water dirt or other impurities from the fuel before the fuel passes through the pump or carburetor The primer assembly operated from the control panel injects raw
75. gasoline and lubricant mixture is used Pour mixture into tank through a fine mesh strainer d Caution the customer not to operate a new engine at continuous full power until at least one tankful of fuel has been used During this time short periods of full power may be used Instruct the cus tomer to follow the break in procedure described in the Owner s Manual e Be sure that the customer understands how to operate the engine correctly especially such things as the neutral lockout com pression release choke electric starting and reverse shift lever TUNE UP PROCEDURES Components which affect engine power and performance can be divided into three groups namely 1 items affecting compression 2 items affecting ignition 3 items affecting carburetion Any tune up procedure should cover these groups in the order given Correction of items affecting carburetion should not be attempted until all items affecting compression and ignition have been corrected satis factorily Attempts to overcome compression or ignition system defi ciencies by altering carburetor settings will result in poor overall performance or increased fuel consumption This section covers only those parts of a tune up which involve adjustments cleaning and check ing for performance Trouble shooting procedures are covered in Sec tion 4 Repair and replacement of parts as determined through trouble shooting is covered in Sections 6 through 11 a Te
76. gh replacing a single part seems to have corrected the trouble For example replacing points may have increased the spark coil output but further improve ment may be realized if a condenser is found to be weak and is replaced The following values are provided for checking the ignition coil 112931 Graham Tester Model 51 Maximum Secondary 30 000 Maximum Primary 4 0 Coil Index 60 Minimum Coil Test 30 Gap Index 50 Merc O Tronic Operating Amperage 0 9 Primary Resistance 1 3 to 1 7 ohms Secondary Resistance 60 to 70 index number Stevens Tester switch B Index Reading 0 8 to 1 0 Stevens Tester Model 75 Switch B Index Reading 22 using MA 12 Adapter MAGNETO REMOVAL a Pull starter rope out and tie knot See Figure 7 4 b Remove one screw from bracket on both sides of instrument panel See Figure 7 4 c Remove two screws from top steering column bracket See Figure 1 4 4 Remove three screws holding bottom rear of instrument panel Loosen jam nut on reversing lever Screw handle out of lever See Figure 7 5 CHOKE M CHOKE LEVER 9 CABLE PULSE LINE Figure 1 6 1 3 C STEERING COLUMN BRACKET SCREWS 4 Figure 7 4 INSTRUMENT PANEL Figure 7 6 INSTRUMENT 17175 AIR DUCT Oris oe MANUAL F STARTER RATCHET MOUNT OUTER FAN 3 HOUSING amp
77. gh resistance which will limit current flow Visually inspect the coil mounting and connections before condemning a coil Test the coil for correct resistance using the ignition analyzer NOTE Magneto drive coils can be tested for correct resistance without removal of starter housing and flywheel Separate engine con nector Ref Figure 7 9 Put ohmmeter leads across gray and light blue lead connector half Set meter on low ohms scale reading should be 8 ohms Points must be open or reading will be zero ohms Points can be opened by rotating flywheel IGNITION COILS Ignition coils see Figure 7 18 should be tested for correct secondary resistance correct primary resistance coil polarity and coil output See Page 7 3 In addition the coil insulation should be tested for leak age The ignition coil should give a secondary reading between 18000 and 22000 volts at 200 500 RPM Raa Perform all tests wooden or insulated bench top to prevent leakage or shock hazards Follow the equipment manufacturer s instructions A low reading on the tester indicates a weak coil which must be replaced No attempt should be made to improve this spark by increasing primary current a coil is defective if it cannot be made to give a good reading on the specified pri mary current Coils should be installed with primary terminals aligned fore and aft to avoid accidentally grounding primary circuit See Figure 7 18 HIGH T
78. gp FRONT AXLE TRUCK OUTER BUSHING PIVOT ARM 6 PIVOT AXLE AXLE BERS SPACER TRUCK SPACER REAR AXLE SHORT PIVOT BUSHING BEARING gt PIVOT ES RETAI NER E AXLE SPACER SEN BEARING A i PIVOT ARM TRACK ADJUSTING amp dose ANCHOR SCREW 17504 Figure 11 7 Remove pivot arms spacers bushings and springs from pivot axles 4 Wheels and spacers will now slide off front and rear truck axles CLEANING INSPECTION AND REPAIR A torn track cannot be vulcanized it must be replaced Liquid neoprene can be applied to a frayed track to help restore its original appearance Bearings are sealed therefore require no greasing Turn bearings in hand Sealed bearings do not turn freely but if they are rough they must be replaced Axles check for straightness by rolling one flat sur ace Replace if bent Splines inspect for excessive wear Sprockets check for excessive wear or Nylon peeling or worn off Oil plug must be in good condition and in place on front axle spline to retain oil in chain case Check condition of seals Check nylon truck bushings for cracks or excessive wear Replace if damaged FRONT AXLE ASSEMBLY a Refer to Figure 11 6 for assembly of sprocket wheels to front axle Assemble bearings flangettes gasket and O ring to front axle as sembly See Figure 1
79. gt gt lt 1 i P a a b UC a J d 4 acm 4 i T 1 5 TI b x 4 tae i F y w 1 JOHNSON MOTORS 7 WAUKEGAN ILLINOIS U S A i bm E 1 L E 1 1 es iv Ta a rae LI 7 2 z k L LIE 4 s Sex ny a Q 4 gt 1 D a gt 7 z 1 E TT amp TH
80. h tension leads so that engine can be cranked without firing Connect voltmeter across starter motor see Figure 7 37 with positive 4 lead to starter motor terminal and negative lead to ground on starter frame d Turn ignition switch to START to crank engine and observe volt meter reading as quickly as possible Avoid running starter motor continuously for more than 30 seconds during test to prevent overheating Allow ample time between tests for starter motor temperature to normalize Volt meter readings will rise as starter temperature increases LE HALF SHEAVE ROTATION STARTER MOTOR WITH SHEAVE DISENGAGED i77 Figure 7 35 TEST Figure 7 36 TEST VOLTMETER Figure 7 37 7 14 2 25 VOLTS XS e youre 25 VOLTS P 1 D 5 25 VOLTS 477 22 TES nc F SL 2 25 VOLTS 4 pen T F VOLTMETER GROUND ON MOTOR AREA THAT 15 FREE OF CLAMP THIS LEAD FIRST TO PREVENT ARCIMG THREADS Figure 7 40 e lf starter motor turns engine at normal cranking speed with a volt age reading between 9 5 volts minimum and 10 5 volts maximum starter motor is satisfactory If available voltage reading at the starter motor is low review the following chart for probable causes Starter System Voltage Drop Te
81. having electric starting this alternating current output is converted to direct current by a diode bridge rectifier and used to charge the bat tery Direct current from the battery is then used to power the head light and taillight and the electric starter motor GASKET LEAF STOP LEAVES 3 3 HOLE FOR FUEL INTAKE PUMP PULSE MANIFOLD ACTION GASKET LEAF PLATE AND BASE 55 Figure 3 4 FUEL FORCED UPWARDS P PERMANENT MAGNET N NORTH POLE SHOE S SOUTH POLE SHOE FLYWHEEL LAMINATED COIL CORE Figure 3 6 17088 INDUCED LOW VENTURI PRESSURE d BY ATMOSPHERIC PRESSURE 17138 POWER FLOW The transmission assembly transmits power from the engine to the front axle which propels the vehicle along the track The primary sheave assembly is attached directly to the crankshaft The secondary sheave assembly has its own mounting pedestal and is larger in diam eter than the primary sheave assembly The two are connected by a transmission belt PRIMARY DRIVE The primary sheave is centrifugally operated and engages the trans mission belt when the engine speed reaches approximately 2700 rpm When the engine is rotating at idle speed or below 2700 rpm the trans mission belt rides on a ball bearing between the halves of the primary sheave assembly see Figure 3 7 The primary sheave assembly halves are separated by compression spring in the hub of the movable sheave ha
82. ht and the electric starter motor See wiring diagrams at end of manual This section gives complete service procedures on all components of the ignition and electrical systems breaker point adjustment and starter motor belt adjustment Principles of magneto operation are dis cussed in Section 3 TEST EQUIPMENT The test procedures outlined in this section require the use of a mul titester called a volt ohm milliammeter or an ohmmeter These in struments can be obtained from local or national electronics supply houses see Figure 7 2 DO NOT use a test instrument having more than a 12 volt source to check rectifier diodes To determine accurately the condition of components of the ignition system an ignition analyzer should be used Without the use of test equipment coils condensers or breaker point assemblies may be re placed needlessly A wide variety of ignition analyzers are available from various manufacturers In addition some automotive testers having the proper specifications can be used The use of the Graham Merc O Tronic or Stevens ignition analyzers are particularly recom mended since these units have provisions for checking all functions of the ignition system see Figure 7 3 MERC O TRONIC STEVENS Figure 1 3 Detailed instructions for the use of any tester are provided with the unit therefore only general information is given here All components of the ignition system should be checked even thou
83. if paint has deteriorated repaint With the engine oper ating at idle speed 1300 to 1600 rpm this painted mark can be seen in center of timing hole when light is focused there Timing slot is approximately 7 8 inch long and is located above the man ual starter at the 12 o clock position in the outer fan housing see Figure 7 24 SPARK PLUGS The condition and appearance of spark plugs taken from an engine may be a guide to the type and source of engine trouble Proper spark plug heat range and normal engine conditions will produce powdery deposits of a rust brown to grayish or tan color on the firing end of the insulator and a minor degree of electrode wear see Figure 7 25 Highly leaded fuels may produce white to yellowish powdery deposits on the firing end of the spark plug These deposits will not interfere with normal spark plug performance if plugs are cleaned at regular service intervals See page 4 3 for a discussion on spark plug heat range a If the insulator tip is an exceptionally light tan or whitish color or the center electrode burned away the heat range may be too hot see Figure 7 26 b A dark black or sootish coloration wet appearance ordinarily indicates the heat range as being too cold see Figure 7 27 Black sooty deposits on the entire firing end of the spark plug result from incomplete combustion due to an overly rich air fuel mix ture incorrect choke setting or misfiring caused by faulty igni
84. ings to inside to chassis b Place idler wheels on top of track Torque idler axle screws to chassis 20 25 ft lbs TRUCK REASSEMBLY 1 Assemble wheels and spacers to their original positions on the front and rear truck axles Application of a light oil on the axles will assist in this procedure Apply Standard Oil Rykon EP 2 grease under nylon bushings and assemble to axles Assemble pivot arms and springs Assemble hanger to pivot axle 2 12 1 SECTION 12 LUBRICATION AND STORAGE TABLE OF CONTENTS ENGINE LUBRICATION 12 2 FUELS AND LUBRICANTS 12 2 2 4 FUEL CONDITIONER 12 2 FUEL BLENDING 12 3 LUBRICATION RECOMMENDATIONS 12 3 PREVENTIVE MAINTENANCE 12 4 AIR FILTEBH 24 12 4 FUEL FILTER FUEL PUMP 12 4 FUEL FILTER SCREEN CARBURETORS 12 4 12 4 PREPARATION FOR STORAGE 12 4 REMOVAL FROM STORAGE 12 5 12 2 M co 4 LC SWALLOWED ANLI PINCALITUINS A1 LL Figure 12 1 ENGINE LUBRICATION Since fuel vapors are first compressed in the crankcase of the two cycle engine the most practical method of lubrication is by mixing the lubricant with the gasoline As the mixture of lubricant and gasoline enters the crankcase the gas
85. ings with especially heavy carbon deposits or hardened grease should be soaked in a separate container of solvent c Use a spray gun with air filter and a cleaning solvent to flush each bearing until all dirt and residue have been removed Blow solvent out of bearings using dry filtered air Be careful not to spin bearings by force of air Figure 9 17 4 Since dry bearings rust rapidly lubricate them immediately light clean oil Rotate them a few times to spread the oil film and place them in a clean covered container for inspection e Discard and replace any bearing that shows any of the following 1 Rusted balls rollers or races 2 Fractured ring This may be caused by forcing a cocked bear ing off a shaft or by too heavy a press fit 3 Worn galled or abraided surfaces These may be caused too loose a fit or a bearing locked by dirt and turning on the shaft or in the housing 4 Badly discolored balls rollers or races This is usually due to an inadequate supply of lubricant Moderate discoloration is not a cause for discard f If bearings must be replaced remove the old bearings using the following procedure Use special bearing removal tool shown Figure 9 21 Position lips of half shells behind bearing and over extractor Slide retaining ring over half shells Turn ex tractor center screw to remove bearing This tool is must if main bearing replacement is required Do not lose shims bet
86. keyway is 180 degrees oppo Site breaker point pivot pin This will bring low point on cam next to fiber block facilitating assembly Remove cam from crankshaft and install correctly in the cam mechanism on the flywheel as shown in Figure 7 22 Place fly wheel on crankshaft When flywheel and cam are properly seated outer edge of flywheel will be approximately 1 32 inch above shoulder on crankshaft DO NOT use force it is impossible to position flywheel properly remove it and repeat above procedure Place washer and flywheel nut in position Hold flywheel with bar and torque flywheel nut to 40 45 foot pounds See Figure 7 23 TORQUE FLYWHEEL NUT TO 40 45 FT LBS ML Figure 7 23 s HIGH TENSION LEAD IGNITION A 4 Figure 7 19 MACHINED BOSSES Figure 7 20 CRANKSHAFT OQ WOODRUFF fe Nt 17217 1 8 4TH FIN _ COUNTER CLOCKWISE FLYWHEEL KEYWAY Figure 7 24 Figure 7 25 4 Figure 7 26 1 Reassemble remaining items in reverse order of disassembly k When this procedure is followed engine is timed correctly without further adjustment To recheck use an automotive timing light either a 12 volt or 110 volt model One of the cooling fins on the flywheel out from the keyway has a small raised boss The fourth fin counterclockwise after the fin with boss should be painted yellow
87. l it bottoms so that there is adequate screw engagement to hold breaker point gap of 020 for used points in good condition or 022 for new points Set points on highest point of cam lobe Breaker point spring tension is predetermined and does not require adjustment Dirt foreign particles and oil are detrimental to contact perform ance The oils and acids from a person s hand even though clean can affect contact resistance Oil deposits on the points will cause them to burn after a very short period of operation If points need cleaning Saturate a piece of bias tape in alcohol or trichlorethylene and work it up and down between the points Finish with a clean dry piece of hard finish paper card stock to remove any residue which might cause point burning NOTE points cannot be cleaned satisfactorily by this method replace them DO NOT use an abrasive stone or file to remove residue across new old breaker contacts new breaker points have high resistance across their contact surfaces making use of a continuity meter during breaker point adjustment difficult snap the con tacts open and closed manually several times CONDENSER The following four factors affect condenser performance each factor must be considered in making a complete condenser test Figure 7 15 BREAKER POST 1 6 IGNITION cols Figure 7 18 Pan Tp 4 f i t7176 Breakdown A failure of
88. lf As the engine speed increases centrifugal effect forces a garter Spring in the end cap outward against the contour of the end cap and axially against the movable sheave half As the sheaves are brought together the transmission belt is forced outward to ride larger diameter of the primary sheave assembly increasing belt speed see Figure 3 8 Since the belt length remains constant the secondary sheave halves spread apart allowing the belt to ride on a smaller diameter In this way the engine transmits power through a variable ratio presenting the engine with a mechanical advantage most favorable for the speed at which it is operating NEUTRAL LOCKOUT POSITION ENGAGED POSITION Figure 3 7 Figure 3 8 A Neutral Lockout Plunger Transmission Belt M Splined Shaft B Emergency Starting G Fixed Half of Sheave N Bolt End Cap to Splined Sheave Crankshaft shaft Garter Activating Ball Bearing O Spring Spring J Spring Cup Neutral Lockout Rod D End Cap K Compression Spring R Spring E Movable Half of Sheave L Neutral Lockout Balls NEUTRAL LOCKOUT A neutral lockout mechanism is used to prevent the drive from en gaging during starting warm up period and idle When the neutral lockout plunger is actuated a cone on the end of the plunger raises two balls through the splines of the primary sheave assembly and into the path of the movable sheave half preventing it from engaging the belt The neutral l
89. long time Is this a new characteristic Check fuel lines and pump Engines not used for long periods accumulate water in fuel systems due to con densation Check fuel pump Check fuel Engine will not start well on stale fuel Check choke Check fuel system for leaks and Check fuel for water and dirt Check ignition Check ignition coil output voltage to spark plug Recommended use of Neon light spark plug tester SAFETY PRECAUTION Do not allow spark engine compartment area where fuel is present be cause of potential fire hazard Check timing Check key in flywheel Itmight have been lost or sheared off allowing flywheel to rotate on crank shaft causing engine to be out lof time Primer might have air leak or bac check valve causing pump to loose prime See Section 6 Fuel System Stale fuel causes gumlike residue Carburetor may require cleaning See Section 6 See Section 7 See No Ignition High Tension 8 HARD STARTING HOT Ask these questions first Has engine always done this Is this new condition Did engine refuse to start after being run Did engine run rough before it was shut off Seem to load up fuel pump vapor locked Choke opening fully Has operator recently changed 1 Brand or type fuel 2 Brand or type of lubricant 3 Spark plugs Ch
90. ls top of ignition coils Pul high tension leads from ignition coils see Figure 7 15 Loosen ignition coil clamp screw to remove ignition coils TESTING For conclusive testing the ignition coils should be removed See Fig 7 15 The breaker point assembly condenser and magneto drive and alternator coils however are tested in position and are removed only for replacement FLYWHEEL Check charge polarity with a compass Compass arrow should point in direction of arrow on flywheel BREAKER POINTS Breaker points can now be inspected and replaced if necessary Under normal running conditions breaker point contacts will appear slightly rough and gray in color Abnormal points will appear excessively pitted and may have a considerable amount of material transferred from one contact surface to the other and will generally be blue in color Severe pitting burning or bluing can usually be traced to such condi tions as a faulty condenser or deposits of foreign material especially grease or oil on the contact surfaces Faulty condensers require re placement Foreign deposits can be attributed to careless handling of points during installation use of excessive lubricant on the oiler wick or a leaky front crankcase seal Wipe breaker point post clean before installing new breaker points to ensure a clean surface for the breaker point bushing to pivot on see Figure 7 16 Turn the eccentric adjusting screw into the plate unti
91. ly at the start of the season It is seldom advisable to attempt to improve performance by correct ing one two items only Time will be saved and more lasting results obtained by following a definite and thorough procedure of analysis and by correcting all items affecting power and performance FUEL SYSTEM A fresh fuel mixture with the correct ratio of lubricant and gasoline is necessary for peak engine performance The tank should be removed emptied of old fuel rinsed out installed and refilled with a fresh supply at the beginning of the season and at every tune up A stale fuel mix ture may cause hard starting stalling and faulty operation An alter native to the removal of fuel at the end of the season is the use of OMC 2 4 FUEL CONDITIONER This additive stabilizes the fuel andprevents gumming and varnishing Inadequate fuel delivery as the result ofa faulty fuel pump or clogged filter will affect high speed performance Incorrect carburetor needle adjustments may cause operating difficulties at any speed Faulty choke operation or incorrect use of the manual choke by the operator may cause hard starting rough running or poor fuel economy IGNITION SYSTEM Spark plugs having the proper heat range are very important for peak performance of the engine See Section 7 for a complete description of spark plugs A weak spark which may be the result of faulty ignition system components will cause hard starting misfiring or p
92. nd punch the installed welch plug is concave it may be loose and cause an uncontrolled fuelleak The correctly installed welch plug is flat Stake plug at outer edge in three places to install 4 Assemble the gaskets diaphragms and castings in the correct order 5 Assemble the throttle shaft into the carburetor body and attach the throttle shaft clip before assembling the throttle shutter With the shaft secured in place assemble the shutter into the shaft Be certain that the shutter fits accurately into the throttle bore in the closed position 6 Assemble the choke friction spring and ball into carburetor body and assemble the shaft into position Assemble the shutter to the choke shaft Be certain that the choke shutter fits tightly to the carburetor bore in the closed position 7 Insert choke cable assembly through projection on carburetor and insert inner cable through choke lever swivel pin See Figure 6 7 with choke knob flush against face plate on instru ment panel open choke butterfly valve full open and tighten screw to retain Inner cable in swivel pin Tighten set screw on carburetor projection just enough to hold cable firmly Work choke knob to check for correct adjustment or possible binding 8 Assemble the carburetor to the intake manifold Install fuel lines and air filter to carburetor See procedure on page 6 7 for installing new fuel line tie straps Assemble throttle cable to carburetor Se
93. ner benzol or any solvent with a blend of these in gredients unless the rubber parts and gaskets are removed If you are in doubt about your solvent test a used part in it and ob Figure 6 2 serye the reaction Remove air filter fuel lines and mounting screws from carburetor E 3 _ THROTTLE CABLE CHOKE CABLE DISASSEMBLY CLEANING REPAIR AND REASSEMBLY a Remove the idle speed mixture screw 14 washer and tension spring Inspect for damaged threads see Figure 6 8 b Remove the metering diaphragm cover 29 the metering dia phragm 28 and gasket 27 Inspect the cover for nicks dents or cracks that might hamper operation Inspect the metering dia phragm the center plate must be riveted securely to the diaphragm and the diaphragm should be free of holes and imperfections The gasket should be replaced if there are holes or creases on its sealing surface The parts must be reassembled in the correct order The gasket should be assembled onto the carburetor body casting first then the metering diaphragm is assembled next to the gasket Remove the hinge pin retaining screw 25 the hinge 23 inlet control lever 26 and the inlet tension spring 24 Use caution in removing these parts Spring pressure may push the inlet control lever out of the casting Inspect the parts for wear or damage The inlet control lever must rotate freely on the hinge pin d Handle the inlet spring care
94. o be During storage volatile agents as well as anti gum and anti varnish agents evaporate from the gasoline that remains in the fuel filter The result is contamination of the filter element with a clear form of varnish This varnish is not readily soluble in gasoline or cleaning solvent therefore the filter should be re placed at the start of each season NOTE Since the purpose of the filter is not only to trap dirt but also to prevent moisture from entering the carburetor do not attempt to run the engine with the filter element removed REASSEMBLY a Reassemble the fuel filter Do not overtighten filter cap to fuel pump body b Attach fuel pump and filter assembly to plate with screws Figure 6 13 Reconnect fuel hoses and secure with new straps per procedure below FUEL PRIMER a The primer is a simple pump which pumps raw fuel from the fuel line thru check valves directly into the intake manifold above the leaf valves see Figure 6 12 b To check operation of the primer disconnect hose from manifold check valve spurt of fuel should be evident when the plunger is depressed If little or no fuel is discharged check the valves in the fuel line and fuel line fitting for leakage or sticking refer Figure 6 1 c Primer cable should be adjusted so that primer knob contacts the instrument panel face plate when knob is depressed and piston has traveled full stroke AIR FILTER The carburetor is equipp
95. ockout is spring actuated and will engage only when the engine is below approximately 2000 rpm When the engine is running above approximately 2000 rpm the garter spring will expand by centrifugal effect See Figure 3 9 The garter spring will then ride up the ramp of the end cap and push the movable sheave toward the fixed sheave In doing this the movable sheave has covered the holes in the splined shaft When the neutral lockout knob is now pushed in the plunger cannot move in because of the interference by the neutral lockout balls Spring R will therefore be compressed as shown in Figure 3 9 If the engine speed is now reduced to idle 1300 1600 rpm the garter spring will close and allow the movable half of the sheave to move away from the fixed sheave Spring R will then push the plunger inward The neutral lockout balls will then move outward through the splined shaft The movable sheave will now be locked out in the neutral position See Figure 3 7 SECONDARY DRIVE The secondary drive mechanism incorporates a torque sensing device that detects the need for more power for steep inclines or deep snow The mechanism immediately forces the secondary sheaves closer to gether to lower the transmission ratio and provide a higher torque to the drive chain and track The drive ratio varies from 3 3 to 1 in low to 67 to 1 in high which yields an overall driye range to approximately 5to 1 Power is trans mitted from the secondary sheave
96. olenoid which makes and breaks the high current circuit between the battery nd the starter motor The starter solenoid see Figure 7 34 closes the circuit through a movable contact disc which strikes two terminal contacts that are con nected to the starter motor circuit The solenoid winding when ener gized exerts a magnetic pull the solenoid plunger causing it to move the contact disc against the terminal contacts The starter motor sheave is disengaged when at rest and when engine is running rotation of the starter motor drives the pin on the mo tor shaft against the cam on the movable half of the sheave forcing it to move in a lateral direction toward the fixed half of the sheave engaging the starter belt When the engine starts the sheave is driven faster than the motor and sheave halves separate to the disengaged position See Figure 7 35 am CAUTION Starter belt tension must be set with sufficient slack to prevent the engine from driving the starter motor MAINTENANCE The only starter motor maintenance required is periodic cleaning of the outside of the starter motor and drive check of the starter belt tension No periodic lubrication of the starter motor or solenoid is re quired Starter motor need be removed for reconditioning only every 1000 hours or if the following tests indicate that the starter is not oper ating properly the starter motor does not crank the engine or if it cranks
97. oline is vaporized leaving the lubricant to lubricate the bearings and other moving parts Eventually the lubricant reaches the combustion chamber where it is burned and discharged through the exhaust ports this way the fuel mixture conveys to the engine s moving parts a metered amount of lubricant in proportion to the speed of the engine Both optimum performance and lubrication depend on maintaining the correct ratio between gasoline and lubricant in the fuel mixture use of too little lubricant leads to premature wear and early break down fuel mixture richer in lubricant than recommended is not only wasteful but will contribute to faulty performance and to excessive carbon accumulation in the cylinders and on the spark plugs Frequent spark plug replacement can often be traced to an excess of lubricant in the fuel mixture Instructions for the mixing of fuel during break in and normal operation as given here and in the Owner s Manual should be followed exactly FUELS AND LUBRICANTS The use of an OMC brand 24 1 lubricant or a reputable automotive engine oil SAE 30 SD or SB and a non premium gasoline of like quality is recommended The oil container should be marked Service SB or Service SD Additional markings such as SA SB or CA indicate oils for other applications and should be avoided Avoid the use of low priced light duty oil container marked only with SA designation or multiple viscosity oils such as SAE 10W30
98. oor high speed performance The spark plugs and ignition system components are frequently checked first in a tune up because of their importance to the operation of the motor COMPRESSION Compression must be well sealed by the piston and piston rings in the cylinder to realize maximum power and performance See Figure 5 1 A compression check is important because an engine with low or uneven compression cannot be tuned successfully to give peak performance It is essential that compression be checked before proceeding with an engine tune up An automotive type compression gage may be used as follows Make certain that choke is open throttle is wide open and both spark plugs are removed THE COMPRESSION RELEASE KNOB MUST BE COM PLETELY Turn the engine over quickly three or four times with the manual starter Compression should be 105 pounds per square inch minimum NEW VEHICLE DELIVERY Complete instructions for putting a new snowmobile into operation are included in the Owner s Manual and assembly instruction packed with each snowmobile Be sure the customer receives this manual and understands the instructions given in it The following listis reminder of important things to check when putting a new snowmobile into op eration a Be sure spark plugs are installed and tightened securely with spark plug gaskets in place c Be sure spark plug wires are securely attached to spark plug ter minals c Be sure the correct
99. ottom of primer and to fuel pump Reinstall brake caliper to secondary Brake cable adjustment should not have been disturbed See Section 10 if adjustment is required Reconnect fuel gauge cable and replace cap Reconnect throttle and choke cables to carburetor See Section 6 for cable adjusting procedure Reinstall manual starter assembly to engine Remove knot in rope and feed rope through opening in instrument panel Feed through hole in grip and tie knot 9 11 BREAK IN 1 For the first tankful of fuel the vehicle must be operated at reduced speeds 2 Allow engine to warm up before putting vehicle in gear Start out slowly avoid jack rabbit starts DO NOT overspeed engine Operation in extreme cold weather can cause a slow down in the drive and track mechanism When this occurs block up rear of snowmobile and place front edge of skis against stationary object and run to free mechanism DO NOT over speed or run vehicle for prolonged periods as this can damage drive lugs on track Observe fuel mixing precautions as described in inside front cover Figure 9 27 IMPORTANT Adjust drive chain tension after the first 3 hours of operation Refer to Section 10 for drive chain adjustment instructions Adjust track tension after the first 10 hours of operation Refer to Section 11 for track tension and track alignment adjustment instructions MUFFLER REMOVAL 1 Remove four muffler mounting screws
100. panel Lift off instrument panel assembly r Remove fuel lines from fuel pump s Disconnect spark plug leads See Figure 9 8 Disconnect red lead from electric starter motor t Loosen two muffler clamps See Figure 9 27 Loosen screws retaining muffler to chassis u Remove four engine mounting bolts Engine and electric starter assembly is now free to be removed from chassis DISASSEMBLY a Remove carburetor intake manifold and leaf valve assembly For detailed instructions see Section 6 b Remove fan housing c On electric start models loosen starter belt tension remove belt tension bracket and starter d Remove spark plugs Remove electrical connector assembly Re move flywheel and magneto cam For detailed instructions see Section 7 RUBBER BUSHING STEERING COLUMN FLANGE Figure 9 7 9 4 PULL COVER e Remove primary drive assembly See Section 10 STRAIGHT OFF WITH SLIGHT TWIST f Remove exhaust manifolds Remove cylinder and crankcase group from engine frame assembly h Remove compression relief valve SPARK PLUG i Remove the cylinder stud nuts and lockwashers The cylinder barrel can now be removed from the crankcase See Figure 9 9 CYLINDER STUD NUTS Figure 9 9 NOTE Cylinders and pistons can be serviced with only the cylinder barrels removed Remove screws from crankcase halves and drive out two alignment roll pins from flywheel side Heat up crankcas
101. ration of shift mechanism moving from forward to re verse several times Use a quick abrupt action Be certain that the reverse lock clevis goes over center see Figure 10 19 each time PLATES LINK Wu PIN SHIFT ROD ASSEMBLY SHIFT HANDLE SPRING RETAINER BRACKET Figure 10 18 REVERSE gee RING PINION GEAR SHAFT LINK WASHERS 17523 Figure 10 18 11 1 SECTION 11 STEERING TRACK AND SUSPENSION TABLE OF CONTENTS BDESLBIPTION Leave 11 2 SIERPBENG 4 11 2 DISASSEMBLY 11 2 CLEANING INSPECTION AND REPAIR m 11 2 REASSEMBDLY 11 2 SKI saaa Lieg TRACK AND SUSPENSION 11 3 TRACK TENSION ADJUSTMENT 11 3 TRACK ALIGNMENT ADJUSTMENT 11 3 REMOVAL OF TRUCKS AND TRACK 11 4 FRONT AXLE DISASSEMBLY 11 4 REAR AXLE DISASSEMBLY 11 4 TRUCK DISASSEMBLY os 2154 CLEANING INSPECTION AND waa age 11 5 TRUCKS AND AXLES REASSEMBLY 1156 11 2 4 DESCRIPTION CENTER PUNCH a REFERENCE This section gives complete service instructions on the snowmobile MARK steering track and suspension STEERING DISASSEMBLY Support front end of snowmobile to r
102. reen IMPORTANT Do not alter return line elbow openings This elbow controls inlet pressure and fuel flow to prevent vapor locking in carbu retor and fuel pump h Welch plugs seal the idle by pass ports and main nozzle ball check valve from the metering chamber Accumulated dirt can usually be blown out through the mixture screwholes However an unusu ally dirty carburetor requires the removal of these plugs Drill just through the welch plug carefully with a 1 8 drill Drilling too deeply may ruin the casting or the ball check valve Usea small punch to remove the plug HIGH SPEED NEEDLE VALVE LOW SPEED NEEDLE VALVE i Figure 6 5 HIGH THEN PUSH DEPRESS HERE TAB DOWN WALL TOO LOW DEPRESS HERE PRY UP HERE CONTROL LEVER Figure 6 6 INSTRUMENT PANEL PROJECTION SWIVEL SET CHOKE PIN SCREW CABLE 17173 Figure 6 7 Inspect the idle by pass holes to insure they not plugged Do not push drills or wires into the metering holes This may alter carbure tor performance Blow plugged holes clean with compressed air Re move the main nozzle ball check assembly 21 pressing it into the primary venturi Press the new part in where required so its bottom surface is flush with the nozzle well surface The nozzle pipe must be below the welch plug to receive enough fuel An engine with a defective check ball 19 will not idle unless the high speed mixture screw is shut off R
103. roughly see Sec tion 6 Install tank refill with fresh fuel mixture and check primer operation Inspect fuel pump and hoses Clean filter or replace filter ele ment and gasket Inspect and clean fuel filter under carburetor fuel inlet elbow Thoroughly lubricate snow machine see Section 12 Tighten all external bolts nuts and screws and retorque cylinder head nuts and spark plugs to specified torque Check track tension and ski alignment see Section 11 n Start engine and allow to warm up Check track alignment see Section 11 o Repeat test run on vehicle Check carburetor needle adjustments p After engine has run sufficiently to indicate satisfactory condition stop and restart it several times Operate it at high and low speeds Check acceleration from low to high speed Clean and dry snow machine thoroughly before returning it to customer Fog motor for storage using OMC Accessories Rust Preventative Oil IGNITION TIMING ADJUSTMENT New or Readjusted Points See magneto removal in Section 7 Set ignition points at 020 for used points in good condition or 022 for a new point set COMPRESSION RELEASE VALVE ADJUSTMENT Check for 1 32 to 1 16 clearance when compression release knob is pushed in See Figure 5 2 Turn out on jam nut and correct clearance with adjustment screw shown in Figure 5 3 Operate compression release knob to check for binding in cable Lubricate the compression rel
104. round primary sheave FIXED 5 Spread halves of secondary sheave by pulling movable half M m SECONDARY toward steering column SHEAVE EH 6 Work bottom of belt under and around the movable half of secondary sheave and roll sheave forward Belt will ride up Figure 9 26 and into secondary sheave 1 Reconnect neutral lockout cable to bracket and actuating arm See Figure 9 5 Install belt guard Reconnect red lead to electric starter motor Install starter belt Adjust tension as described in Section 7 Install spark plugs and connect leads Reconnect cable harness to air baffle Install fuel inlet and return lines to carburetor and pulse and primer lines to intake manifold on crankcase Reinstall instrument panel to chassis Feed primer assembly forward under carburetor and install to chassis See page 6 7 for adjustment procedure Secure instrument panel to chassis with three screws in rear of panel and one on either side at the instrument panel to chassis bracket Reinstall steering column First replace three bolts in lower flange Torque to specifications Install rubber bushing and yoke See Figure 9 7 Reconnect speedometer and tachometer cables engine ignition light switch and cigarette lighter connectors Reconnect compression relief cable to compression relief valve See page 5 5 for adjustment procedure Screw shift handle back onto reverse operating rod Reconnect fuel lines to b
105. rtens the life of the battery DISCONNECT one of the battery leads before attaching battery charger to battery SLOW CHARGING Adjust electrolyte to proper level by adding water then charge bat tery at a maximum rate of 5 amperes until fully charged Full charge of the battery is indicated when all cell gravities do not increase when checked at three intervals of one hour and all cells are gassing freely Due to this low rate during slow charging plenty of time must be 1 lowed Charge periods of 24 hours or more are often required BATTERY WARRANTY PRESTOLITE BATTERY WARRANTY Warranty on Prestolite batteries is covered directly by Prestolite through their authorized battery service stations for a period of 18 months The warranty period starts on the date the snowmobile is delivered to the original owner Should a battery fail due to inherent defects during the first three 3 months of service it will be replaced no charge basis Bat teries that fail during the balance of the warranty period 15 months will be replaced on a prorata basis STARTER SYSTEM DESCRIPTION The electric starter system consists of the starter motor starter solenoid and the necessary cables and wires with their connectors The starter motor converts electrical energy from the battery into mechanical power which is transmitted to the engine through the starter belt The starter switch controls the operation by activating the starter s
106. s in main shaft spline in horizontal plane Retain neutral Va SW lockout balls in holes with Rykon EP 2 grease j PRIMARY 2 primary spring on shaft with closed side of spring cup 1 toward bearing See Figures 10 5 and 10 6 Y Place sliding sheave assembly on shaft compress spring and lock in place with strap Service Tool No 261906 3 4 Assemble activating spring and end on shaft making sure end SHEAVE HUE BEN cap splines engage shaft splines 2 5 Before placing end cap bolt in shaft check to see that neutral Figure 10 6 lockout balls have not fallen from their holes in main shaft x Tighten end cap bolt to 90 100 ft Ibs See Figure 10 7 J If serrations do not allow alignment of holes in lockplate and end a cap turn lockplate over androtate until aligned position is obtained TORQUE 90 100 LBS Torque lockplate screws to 60 80 in lbs 8 Check the neutral lockout plunger to see that it snaps properly When neutral lockout is pushed in the sliding sheave must not slide on spline far enough to contact belt When neutral lockout is out normal operating position the sliding sheave must slide freely on spline restricted only by the primary spring 9 Clean inside of sheave halves of any grease that may have accumu lated on them 10 Reinstall transmission belt as described in Section
107. s primarily dependent on the piston rings and cylinder these other sources of leakage should be investigated when compression loss is noted Compression leakage will occur if the compression relief valve link age is adjusted with insufficient clearance on the cable ends The re lief valves vent combustion chamber pressure through a by pass port into the exhaust system Compression may also be affected by the fuel induction and exhaust systems Since the fuel vapor is first compressed in the leakage here will affect engine performance Possible trouble spots include leaf valve assemblies seals between crankcase halves and crankshaft bearing seals Exhaust ports which have become clogged because of excessive deposits of carbon will hinder the efficient transfer of exhaust gases Excessive carbon build up on piston heads or elsewhere in the cyl inder walls can result in a loss of power Following the trouble check chart provided at the end of this section and the recommended tune up procedures given in Section 5 will assure that all areas affecting fuel induction compression and exhaust will be considered as part of every trouble shooting procedure engine with low or uneven compression cannot be successfully tuned for peak per formance It is essential that improper compression be corrected be fore proceeding with an engine tune up SPARK PLUGS The spark plug provides a gap inside the combustion chamber a
108. s using excessive torque can strip the threads in the cylinder head 3 Installation of plugs on dirty gasket seal 4 Installation of plugs in corroded spark plug hole threads BATTERY Electric start model snowmobiles should not be started and op erated with battery not connected in circuit Operation without battery can damage rectifier If snowmobile must be operated without battery disconnect two yellow alternator leads from rectifier and turn light switch to ON DESCRIPTION The battery s primary function is to provide power to operate the starting motor however the battery also supplies power to operate the ACCESS TO REAR SPARK PLUG Figure 7 30 1 10 SPILL PROOF CAPS NEGATIVE POSITIVE TERMINAL TERMINAL Figure 7 32 17127 lights when the engine is not running at higher speeds The storage battery is a secondary chemical generator one that produces an electric current by chemical action after having been charged from an outside source Each cell in the storage battery consists of a negative plate of sponge lead and a positive plate of lead peroxide immersed in a solution of water and sulphuric acid After being charged each cell will produce a voltage of about 2 1 volts Six cells connected in series are assembled in case to make up a 12 volt battery SPECIFICATIONS Due to the extreme weather and temperature conditions under which the battery must operate proper battery selection i
109. s very important The battery recommended for best performance is a 12 volt 32 ampere hour battery or better with a minimum of 2 2 minutes cold starting capacity at 150 amperes discharge 0 Fahrenheit and a 5 second volt age reading of 7 8 volts It is important to remember that a customer s complaint of poor starting may be traceable to a battery not having these recommended specifications The dimensions are 7 3 4 long x 5 1 8 wide x T 1 4 high to top of terminals The Prestolite Brand Battery Type 9948X which is included with electric start vehicles is recommended and is manufactured for snow vehicle use It has a one piece molded cover and anchored plates to reduce possibility of vibration damage Battery is shipped dry and activated with an electrolyte INSTALLATION To provide maximum protection from battery acid damage in the event of accidental upset special spill proof battery caps see Figure 7 31 are supplied with the vehicle Make certain the original caps are removed and these special caps are installed The hold down clamp should be tight enough to hold the battery but should not exert undue force on the case If the clamp is too tight dis tortion and damage to battery case will result The hold down bar should be installed as far forward as possible to enable the clamp to snap over battery caps See Figure 7 32 Battery acid is dangerous and will burn the skin as well as cause damage to metal clothing or wood
110. ssive fuel consumption a Hole in fuel pump diaphragm b Carburetor casting porous c Deteriorated carburetor gaskets d Carburetor improperly adjusted e Hole in metering diaphragm Vibrates excessively or runs rough and smokes a Too much lubricant mixed with gas b Idle or high speed needles too rich c Air passage to carburetor obstructed d Faulty ignition No power under heavy load a Faulty carburetion b Faulty ignition c Breaker points improperly gapped or dirty g Ignition timing too far retarded e Carbon build up on piston head i Cylinder scored or rings stuck g Compression relief valve open h High speed adjustment lean i Spark plugs fouled or misfiring STARTER WON T TURN Check For Engine Lock Up ENGINE OVER Check battery terminals and 4 cables Check solenoid leads for grounding Check for weak battery Turn engine over by hand Eliminate possibility of bad Starter motor by jumping across large terminals of starter solenoid Eliminate possibility of poor ground by running cable direct from nega tive battery lug to starter motor body If engine turns over this would indicate defective solenoid starter switch or broken lead If engine turns over this would indicate poor ground recheck terminals and cables 9NILOOHS 11 L HARD STARTING COLD engine always done this Was engine not used for a
111. st By making a systematic check from the positive battery terminal through the starting circuit and back to the negative battery termi nal any component or electrical connection having excessive re sistance thus causing high voltage drop and subsequent hard start ing can be pinpointed see Figure 7 38 Ground spark plug high tension leads so that engine can be cranked without firing Connect voltmeter and turn ignition switch to START to crank engine NOTE By placing voltmeter leads against battery solenoid and starter motor terminals rather than against connecting cable ends each connection can be tested for high resistance along with component Clean and retighten or replace any connection cable or com ponent having greater than specified voltage drop STARTER MOTOR TESTING The no load test is used to determine quickly the general mechanical and electrical condition of the starter motor The stalled torque test is used to determine whether or not the starter motor has sufficient torque to crank the engine for fast starting No Load Test a Connect starter with an ammeter in series to a 6 volt source see Figure 7 39 Use a tachometer or rpm indicator to indicate armature speed Ammeter should indicate 60 amperes maximum rpm indicator should indicate 4200 rpm minimum If readings are not as speci fied check for binding in starter or failure of windings NOTE If starter motor turns slowly smokes
112. st run vehicle checking particularly the following 1 Neutral lockout a primary sheave locked in neutral 5 3 04 2 Function of compression release 3 Function of brake 4 Engine performance 5 Ski alignment and handling After running snowmobile reduce engine speed to idle and pull neutral lockout knob out to lock transmission in neutral Ac celerate engine to see if transmission is in neutral Neutral lockout is spring actuated and cannot be engaged above approxi mately 2000 rpm Check compression as described above If engine knocks or does not come up to speed check for loose flywheel Remove manual starter and fan housing see Section 8 Rock flywheel back and forth and listen for knocks Excessive wear in crankshaft journal bearings can be detected by moving flywheel back and forth Check for end play by pushing and pulling on flywheel End play tolerance is 011 to 026 If compression and bearing condition checks are not satisfactory engine overhaul is required see Section 9 Test for adequate spark at each cylinder using a spark checker Inspect and test points condenser magneto coils ignition coils timing and spark plug high tension leads see Section 7 Check spark plugs to be sure they are the correct type Clean spark plugs and regap or replace as necessary Check breaker points and clean or adjust as necessary Remove and drain fuel tank flush and clean tho
113. t DO NOT clean plugs on abrasive blasting machines This type of cleaning tends to remove the hard smooth finish from the insulator tip and reduces the tip s resistance to the formation of combustion deposits Blasting also tends to pack the abrasive between the insulator top and the metal shell of the plug the abrasive is not removed before in stalling the plug it may pass through the engine causing piston or cylinder wall scoring After the plug has been cleaned adjust the gap to 028 to 033 inch by bending the side electrode Adjust only the side electrode as attempting to bend the center electrode will crack the insulator Use a round wire feeler gage to measure gap adjustment see Figure 7 29 Poor engine performance and premature spark plug failure may re sult from improper spark plug installation Before installing the plug be sure the plug seat in the cylinder head is cleaned and free from Obstructions Inspect spark plug hole threads clean and coat with DuPage high temperature thread compound before installing plugs 1 ways use new gaskets when installing spark plugs Tighten spark plugs 20 to 20 1 2 foot pounds using a torque wrench Improper installation is one of the greatest single causes of unsatis factory spark plug performance Improper installation is the result of one or more of the following 1 Installation of plugs with insufficient torque to correctly compress the gasket 2 Installation of plug
114. ter rope handle is pulled When the en gine starts centrifugal force moves the pawls outward disengaging them from the ratchet A recoil spring is wound as the rope is pulled and unwinds as the starter handle is returned to the starter housing Never release handle at end of stroke allowing rope to snap back Serious damage will result REMOVAL AND DISASSEMBLY a Raise hood Pull starter rope out and untie knot in handle while holding rope Ease rope back into starter until starter spring is fully unwound d Remove three screws securing starter assembly to outer fan hous ing _ SAFETY PRECAUTION Because of the rewind spring is good practice to wear safety glasses when disassembling reassembling the manual starter e Remove screw pulley to housing and remove all components of starter pulley spindle assembly See Figure 8 2 f Jar the housing pulley side down on bench to dislodge spring and pulley from housing PULLEY TO SCREW 4 WASHER ue HOUSING 17510 Figure 8 2 CLEANING INSPECTION AND REPAIR Wash metal components solvent and blow dry with compressed air b Inspect spring for broken end loops or insufficient tension Examine starter pawls and ratchet for excessive wear Inspect friction ring and spring spindle bushing spindle and re tainers Inspect rope and discard if frayed Replace with starter rope cut
115. the condenser insulation direct short between metallic elements in the condenser This prevents any condenser action 2 Low insulation resistance leakage Prevents condenser from holding a charge All condensers are subject to leakage which up to a certain limit is not objectionable 3 High series resistance Excessive resistance in the condenser circuit due to loose condenser mounting broken strands or poor connections inside the condenser or to defective lead connections This will prevent normal condenser action causing rapid breaker point burning or ignition failure 4 Capacity Determined by the design and condition of the condenser For a complete check of the condenser use a tester see Figure 7 17 which will test the condenser for correct capacity series resistance and leakage resistance Follow the instructions given by the manufacturer of the test equipment The condenser should be replaced if it fails to meet any one of the three tests High voltage is applied to the condenser in the leakage test Handle leads carefully and turn selector switch to DISCHARGE before disconnecting leads from condenser MAGNETO DRIVE COILS A good magneto drive coil will not function properly if incorrectly mounted or connected If the coil heels are not properly aligned with the bosses on the magneto plate the gap between the flywheel magnet and coil heels may be too great Connections that are not clean and tight will cause hi
116. tion components A definite white coloration may indicate the presence of moisture in the combustion chamber Similar deposits are caused by pre ignition Oil fouling deposits wet sludgy deposits and 15 a result of mis firing or of excessive oil in the fuel mixture see Figure 7 28 Burned or overheated spark plugs may be identified by a white burned or blistered insulator nose and badly eroded electrodes Excessive deposits in the combustion chamber a lean fuel mixture or improperly installed spark plugs can cause overheating Figure 7 28 The condition of spark plugs may provide indication of other con ditions requiring attention Inspect each plug and gasket as it is re moved Place the spark plugs in a holder in order of removal to as sist in locating trouble Inspect each plug for worn electrodes glazed broken or blistered porcelain and replace plugs where necessary Plugs that are severely carbon fouled that have blistered or cracked insulator tips or plugs that have eroded electrodes must always be placed Plugs that are slightly contaminated with deposits or which have wider than recommended gap settings can be cleaned and regapped for further use Plugs that appear slightly contaminated can be cleaned by careful scraping using a small knife or similar instrument After combustion deposits have been removed bend the side electrode back slightly so that the center electrode can be filed fla
117. ton from connecting rod See Figure 9 12 Piston wrist pin hole marked Loose should be up when pressing out wrist pin to prevent piston damage CLEANING INSPECTION AND REPAIR Figure 9 11 When using trichlorethylene as a cleaning agent use well ventilated area at normal room temperatures and under no circumstances heated Trichlorethylene vapors are poisonous CYLINDERS a Remove carbon from exhaust ports and cylinder heads Carbon accumulation in exhaust ports restricts flow of exhaust gases and has a considerable effect on motor performance Carefully scrape carbon from cylinder heads and exhaust ports with scraper or other suitable tool Exhaust ports and all exhaust passages must PIN y be free from carbon deposits to insure maximum performance Clean compression relief valve and check for free action MOUNTING BLOCK Check cylinder walls for excessive wear Measure cylinder bore for size and straightness by using an inside micrometer or dial bore indicator If wear is excessive badly scored replace cyl inders Major portion of wear will be in port area and area cov Figure 9 12 ered by ring travel GASKETS AND GASKET SURFACES a Discard all gaskets seals and O rings Use only new gaskets and seals in reassembly b Remove all traces of dried cement and old gasket material using trichlorethylene or lacquer thinner c Check gasket faces for flatness Under certain conditions gasket
118. ts burned dirty or improperly gapped Cylinder gasket or leaf plate gasket blown 1 Leaking crankcase seals k Coil lead grounded on chassis RUNNING HIGH SPEED ONLY 1 High speed miss 2 a Water in fuel b Spark plug heat range incorrect Spark plugs improperly gapped or dirty cracked insulator Ignition wires loose or broken or faulty insulation Coil or condenser weak Breaker points burned dirty or improperly gapped g Engine improperly timed h Combustion chambers carboned or fouled Poor acceleration low top rpm Incorrect gas lubricant ratio Old fuel Fuel hoses plugged or kinked Fuel filter restricted e Fuel pump or pulse line faulty f Incorrect carburetor mixture adjustments g Float setting incorrect Inlet needle and seat worn or sticky i Timing out of adjustment j Spark plugs dirty or improperly gapped Loose broken or badly insulated high ten sion leads 1 Coil or condenser weak m Breaker points worn or improperly gapped Leaf valves not properly seated or broken Piston rings stuck or scored Excessive carbon on pistons and cylinder head q Compression relief valve improperly ad justed or faulty r Carburetor high speed needle set too lean 3 Idles well but acceleration poor dies at full hrottle a Incorrect gas lubricant ratio b Fuel lines or passages obstructed Fuel filter clogged d
119. um permissible distortion is 003 below wrist pin boss only PISTON RINGS b Install the piston rings on each piston Spread each ring witha ring expander just enough to slip it over the head of the piston and into place see Figure 9 22 Be sure that the rings fit freely in the piston ring grooves Be sure that piston rings are correctly positioned in piston ring grooves When installed on the piston the ring gaps must be staggered to retard compression loss CRANKSHAFT a 57 Install crankshaft shims journal bearings on crankshaft using an arbor press Be sure to support properly to prevent distortion Shims must be installed on crankshaft between the bearing and thrust face of crankshaft Crankshaft end play should not exceed 025 after installation Total dimension across bearing should be 4 930 001 See Figure 9 23 Remove connecting rod caps from connecting rods Apply a coat of OMC NEEDLE BEARING GREASE Part No 378642 to con necting rod bearing area Assemble needle bearings 16 and retainer halves with connecting rod and connecting rod cap to crankpin NOTE Bearing retainer halves are matched DO NOT interchange retainer halves or turn them end for end Attach connecting rod to caps Connecting rod caps are not inter changeable neither may the caps of the same rod be turned end for end Match marks are provided to assure correct assembly Draw a pencil over edge surface on both sides
120. up Absorbs moisture and water in fuel system Extends spark plug life by reducing fouling and misfire FUEL BLENDING To avoid unnecessary cylinder scoring and premature engine wear it is important that the gasoline and lubricant be properly mixed prior to putting the fuel in the tank This is especially true in zero or sub zero climates Unless the fuel and lubricant are properly mixed the engine could operate on a mixture which is too lean until the gasoline and lubri cant have been agitated by then damage would have occurred and the engine would have to run an excessively rich mixture The correct fuel mixture ratio is 24 1 or 1 3 pint of lubricant to each gallon of gasoline 1 Always use a separate clean container for mixing fuel See Fig ure 12 2 Figure 12 2 2 Do not pour lubricant or gasoline separately into vehicle tank 3 prepare the snowmobile fuel properly pour into SEPARATE clean container half the amount of regular grade gasoline required and add all the required lubricant Thoroughly agitate this partial mixture Next add the balance of gasoline necessary to bring the mixture to the required ratio of 24 1 Again thoroughly agitate the mixture A clean funnel equipped with a fine screen should be used when pouring the fuel mixture into the vehicle tank DO NOT POUR GASOLINE OR LUBRICANT DIRECTLY INTO VEHICLE FUEL TANK USE AN APPROPRIATE CONTAINER FOR MIXING AND STORING THE FUEL
121. used by one or more loose or dirty connections Check for corroded or loose connections and for worn or frayed insulation Check the battery cables for possible reverse polarity Connections All electrical connections are readily accessible by opening the hood Although connections are easily made care must be used when fastening terminals together If connectors are not assembled properly one or more of the terminals may back out of the housing preventing one or more of the electrical circuits from operating To eliminate problems due to improper connections examine the terminals on both halves ofthe connectors after assembly to be sure that all terminal ends are in place a If visual inspection of the electrical system shows all components to be in good condition an electrical inspection will be necessary to de termine which component of the charging system is the cause of trouble To check alternator coils connect volt ohmmeter 0 10 ohm range to both yellow output leads of alternator Meter should read 8 ohms 2 ohm CHECKING RECTIFIER DIODES Two methods may be used to check for shorted or open diodes ohmmeter or 12 volt test lamp 1 17 DO NOT use 110 volt test lamp to test diodes Diodes checked with test meter selector in OHMS position OHMS on the Stevens Model AT 100 This is basically a continuity Disconnect all leads from rectifier assembly Check a diode
122. via the pulse line Fasten with screws and lockwashers FILTER FILTER CAP MOUNTING HOLES b Attach primer check valve hose to check valve on manifold c Attach assembled carburetor to intake manifold with screws nuts and lockwashers using new carburetor gasket FUEL PUMP REMOVAL Disconnect two hoses from fuel pump and filter assembly see Figure 6 10 b Remove two screws attaching pump and filter assembly to mount ing plate see Figure 6 10 and remove pump and filter assembly Figure 6 11 NOTE Filter assembly may be removed for cleaning and inspec tion without removing pump assembly by removing filter cap screw see Figure 6 11 CABLE TO PRIMER KNOB BY TO lt h D Ie n MANIFOLD 8 Do not allow fuel to drip hot engine or exhaust manifold because of potential fire hazard VNS FUEL PRIMER PUMP CLEANING INSPECTION AND REPAIR fuel pump components not serviced separately Ifa mal function occurs replace the complete pump b Inspect the filter for accumulation of sediment by removing the filter cap screw and the filter cap see Figures 6 8 and 6 9 Clean the filter cover and fuel connectors in solvent and blow dry LINE FROM FUEL TANK Figure 6 12 Check for a clogged filter element fuel filter element on engine that has been in storage may be clogged without appearing t
123. ween bearing and crankshaft throw ASSEMBLY OF ENGINE Refer to exploded views for correct sequence of assembly Make no forced assemblies unless press fits are called for Make no dry assemblies Lubricate all moving parts with a light film of oil Be sure all parts are clean and free from dirt and grit Perfectly good cylinder walls pistons and rings can be ruined in a few minutes of operation if grit remains after assembly Work in clean surroundings and with reasonably clean hands Coat all bearing surfaces cylinder walls etc with clean oil before assembly NOTE Use new gaskets and seals throughout when reassembling the engine Apply Perfect Seal 4 to both sides of crankcase gasket before assembly PISTONS WRIST PINS AND CONNECTING RODS a Install wrist pin needle bearing in connecting rod using an arbor press b Apply a coat of oil to wrist pin making sure the surface is clean Place a drop of oil in each pin hole in piston Oil wrist pin bearing in connecting rod Heat piston in water approximately 140 F Insert wrist pin through hole in one side of piston Place connecting rod in position in piston then complete wrist pin installation in an arbor press d Replace retaining rings lettered side out making certain they seat securely in the groove provided Figure 9 18 Figure 9 19 Figure 9 20 Check piston with micrometer to determine whether piston has been distorted during assembly Maxim
124. ylinders Tighten nuts in correct sequence to specified torque see Figure 9 25 NOTE Retorque cylinder screws after motor test has been completed and motor has cooled off Figure 9 24 b Assemble exhaust manifolds to cylinder barrels if they were removed The gasket surfaces on cylinders and manifolds must be clean and smooth Place new exhaust manifold gaskets over cylinder studs and assemble exhaust manifolds See Figure 9 10 Install leaf valve assembly intake manifold carburetor and air cleaner For detailed instructions see Section 6 d Attach cylinder and crankcase group to engine frame e Install compression relief valve using Dupage High Temperature Thread Compound applied to the threads INSTALLATION a Install engine and frame to chassis Work exhaust manifolds into exhaust pipe Tighten clamps Tighten screws retaining muffler to chassis Figure 9 25 b Install primary sheave assembly See Section 10 Check primary to secondary dimensions as shown in Figure 9 26 2 574 MEASURED BALANCE PADS d Install steering column assembly Connect control linkages and adjust Check ski alignment as described in Section 9 e Install transmission belt using the following procedure 1 Move belt between neutral lockout actuating arm and primary sheave See Figure 9 5 10 5 2 Work belt between primary and secondary sheaves 3 Move belt between end and engine 4 Loop one end of belt a

1971 Skee-Horse

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