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1973 J30-253E - Vintage Snow

1. 11 2 STEERING 7 4 11 2 DISASSEMBLY 11 2 CLEANING INSPECTION AND REPAIR 1 1 2 REASSEMBLY T vrai SKI ALIGNMENT 11 2 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 5 TRUCK DISASSEMBLY 11 5 CLEANING INSPECTION AND NE N 11 5 Trati iaia Saher 11 5 Trucks and Axles 11 5 REASSEMBLY 11 6 DESCRIPTION This section gives complete service instructions on the snowmobile steering tracks and suspension STEERING DISASSEMBLY 1 Support front end of snowmobile to remove weight from skis 2 Scribe ski column and steering arm to maintain original position for reassembly of skis See Figure 11 1 3 Remove ski and spring assembly from ski column 4 Remove steering arms from ski column See Figure 11 2 9 Disassemble leaf springs if required for servicing CLEANING INSPECTION AND REPAIR a Remove all dirt and old grease from ski columns and from inside ski column tube b Inspect ski column and bushing and replace if worn or bent c Inspect ski runners and replace if worn See torque specs 9 Inspect leaf springs for cracks or weakness e Ins
2. 2 22221 vee 749 STARTER CIRCUIT TESTING TER AURA Glatt te od Oks ee 7 19 STARTER MOTOR TESTING im corde Da dade 7 20 INSPECTION OF STARTER CJ ERUF TENON 45 e 545 ALTERNATOR 2265425246005 25632565 ee 2955 TROUBLE SHOOTING eee eese eur ea na howe Efe 7 22 ACTER RMA TOR COM oh clea Be TEST 1 ALTERNATOR COIL RESISTANCE TEST 1 23 TEST 2 ALTERNATOR COIL OUTPUT TEST 4 4 7 23 CHECKING HECTHIPIED DODES 42 2 22 9 2 2 252 7 24 ALTERNATOR AND CHARGE COIL REPLACEMENT 7 24 BLOCKING DIODE TEST 7 24 RAE sated ova caa 2s La Xxx 7 24 WIMMER SWLECH TEST Ca Y 7 24 BRAKE LAMP SWITCH ow caw ace wile P uio ab ot 7 24 WIRING 4 AT BACK OF MANUAL 1 2 GROUND BATTERY LIGHTS MAGNETO DESCRIPTION The ignition system is made up of the following major components 1 Flywheel assembly Sensor rotor Stator and charge coil assembly Sensor plate assembly PowerPack 1 assembly 6 Ignition coils e
3. 4 h Mt M hie Ly oM ers m 4 iy Mn EVINRUDE ay amp JOHNSON SNOWMOBILE SERVICE MANUAL 30 HP MODELS E 253E J30 253E fj SNOWMOBILE DIVISION OUTBOARD MARINE CORPORATION 3031 NORTH 114th STREET MILWAUKEE WISCONSIN 53222 OUTBOARD MARINE CORPORATION OF CANADA LTD PETERBOROUGH CANADA PART NO 406187 SECTION 1 INTRODUCTION SAFETY SYMBOLS THE PURPOSE OF SAFETY SYMBOLS IS TO ATTRACT YOUR ATTENTION TO POSSIBLE DANGERS THE SYMBOLS AND THE EX PLANATIONS WITH THEM DESERVE YOUR CAREFUL ATTENTION AND UNDERSTAND ING SAFETY WARNINGS DO NOT BY THEM SELVES ELIMINATE ANY DANGER THEIN STRUCTIONS OR WARNINGS THEY GIVE ARE NOT SUBSTITUTES FOR PROPER ACCIDENT PREVENTION MEASURES SYMBOL MEANING SAFETY FAILURE TO OBEY A WARNING SAFETY WARNING MAY RESULT IN INJURY TO YOU OR TO OTHERS Q PROHIBITED WARNS YOU AGAINST AN ACTIVITY WHICH IS OR MAY BE ILLEGAL IN YOUR AREA ADVISES YOU OF INFOR MATION OF INSTRUC TIONS VITAL TO THE OPERATION OR MAINTE NANCE OR YOUR EQUIP MENT Before proceeding with any repair or adjust ments on this snowmobile see SAFETY WARNINGS on inside front cover and on pages 6 6 7 3 7 11 7 17 7 18 8 2 9 6 10 2 10 3 10 8 11 4 11 6 and 12 5 1 1 INTRODUCTION SPECIFICATIONS GENERAL SNOWMOBILE INFORMATION TROUBLE SHOOTING TUNE UP PROCEDURES FUEL SYSTEM a IGNITION AND EL
4. 9 11 ASSEMBLY TO CHASSIS BREAK IN 9 21 MUFFLERS AND EXHAUST MANIFOLDS 9 12 REMOVAL we ote du a Rs 9 12 9 1 SECTION 9 ENGINE 9 2 1 2 PULL COVER STRAIGHT OFF 5 WITH SLIGHT TWIST L Figure 9 4 DESCRIPTION The snow machine is driven by a two cycle twin opposed cylinder air cooled engine see Figure 9 7 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 Before removing hood a Disconnect headlamp wiring Separate connectors by squeezing top and bottom tabs of connector and pull See Figure 9 1 b Remove gas cap and hood hold down nuts c Lift off hood and engine cover d Replace gas cap Remove belt guard and transmission belt See Section 10 Remove throttle cable 1 using the following procedure Depress thumb throttle lever Hold throttle in open position Slip end of throttle cable through nylon pivot pin 2 Remove jam nut on intake manifold and turn cable fitting out of manifold See Figure 9 2 Remove spark plug leads from spark plugs and rear plug clamp See Figure 9 3 Disconnect engine electrical connectors Disconnect plugs 1 from ignition switch and remove headlight plug 2 from bracket on steering column support See Figur
5. Cylinder compression Minindm 644 bd rwy 6 9 105 PSI Ring diameter 2 4 4 4 42 42 4 2 2 0 4 inches Specifications and features may be changed at any time without notice and without obligation towards vehicles previously manufactured TORQUE SPECIFICATIONS Nut Screw Nut Serew Screw Nut Nut Screw Screw Nut Nut Screw Bolt Screw Screw Nut Setscrew Nut Screw ac Screw Nut Nut Nut Nut Nut Screw Screw Nut Screw Screw screw Screw Screw ocrew Ball Joint to Steering Arm and Steering Column Bearing Cup to Chassis Brake Lever to Handle Bar Cable to Solenoid Compression Relief Valve and Plug Connecting Rod Crankcase Cylinder to Crankcase Drive Sprocket Engine Frame to Main Frame Engine to Engine Frame Assembly Exhaust Manifold to Cylinder Flywheel Front and Rear Truck Axles Idler Axle to Frame Primary End Cap to Main Shaft Ratchet Mount to Flywheel Ratchet to Ratchet Mount Rear Axle Pivot Rear Sprocket Runner to Ski Sensor Mounting Plate Spark Plug Stator Assembly to Mounting Plate Steering Arm to Ball Joint Steering Arm to Ski Column Throttle Cable Adjusting Screw Tie Rod Jam Nut to Ball Joint Track Adjusting Bracket to Chassis Truck to Frame Truck to Frame Saddle to Springs General Torque Requirements 3 8 24 110 32 1
6. LEAVES LEAF PLATE AND BASE ASSEM Figure 3 5 GROUND ELECTRODE CENTER ELECTRODE INSULATOR N Figure 3 6 REFERENCE P PERMANENT MAGNET NORTH POLE SHOE 5 SOUTH POLE SHOE FLYWHEEL LAMINATED CORE 82 Figure 3 7 A throttle or butterfly valve in the throat regulates the amount of air drawn through the carburetor To vary the speed of the engine the throttle opens or closes regulating the amount of fuel air mixture 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 forward of the jets to restrict the flow of air When the choke shutter is closed more 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 The system which controls the intake of the fuel air mixture in the two cycle engine consists of set of leaf valves which serve the same purpose as the intake valves on a four cycle engine The leaf valves are thin flexible metal strips mounted between the carburetor intake mani fold and crankcase When the piston is the up stroke it creates a partial vacuum in the crankcase Atmospheric pressure forces the leaves away from the body see Figure 3 5 opening the passage b
7. Leaf block base plate reversed e Carburetor inoperative STARTING MANUAL STARTER 1 Manual starter pulls out but starter does not engage flywheel Friction spring bent or burred b Grease pawls or spring 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 Loose or missing parts d Grease on pawls or spring Clattering manual starter a Friction ring bent or burred b Starter housing bent E d Grease on pawls or spring Dry starter spindle STARTING ELECTRIC STARTER Starter cranks too slowly a b Weak battery Loose or corroded connections or ground connection Starter belt slipping Faulty starter solenoid or solenoid wiring Worn armature brushes or spring Faulty field or armature shorted or open windings 2 Starter will not crank engine b pt Weak battery Loose or corroded connections or ground Broken wire in harness or connector Faulty ignition key switch Faulty starter solenoid or solenoid wiring 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 b C F Incorrect gas lubricant ratio Carburetor idle adjustment too lean or too rich Leaf valve standing open or preloaded shut Spark plugs improperly
8. 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 41 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 Clean and inspect spark plug hole threads Always use new gaskets when installing spark plugs Tighten spark plugs to 20 25 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 Figure 7 40 Figure 7 41 Uv Ano 7 16 2 Istallation of plugs using excessive torque can strip the threads in 3 Installation of plugs on dirty gasket seal POSITIVE 4 Installation of plugs in corroded spark plug hole threads TERMINAL NEGATIVE TERMINAL 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 ignition switch to RU
9. Clean Air Filter Once a season see below Clean or install new Fuel Pump Filter Screen Clean Filter Screen under Carburetor Fuel Inlet Elbow Once a season see below AIR FILTER The carburetor is equipped with an automotive type paper air filter element that should be cleaned once during the operating season and replaced after a year s service When pores in paper are plugged engine will receive a rich fuel air mixture and run rough and get poor fuel economy To clean filter element shake to dislodge dirt particles and blow with compressed air from inside holding nozzle about two inches from filter NOT wash oil filter element See Figure 12 1 FUEL FILTER SCREEN FUEL PUMP WARNING Exercise care to prevent fuel spillage while removing fuel filter when engine is hot The fuel filter is attached to the fuel pump 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 solvent and brush Assemble filter as shown in Figure 12 3 being careful to assemble gasket and filter screen on fuel filter cover Tighten mounting screw securely with screwdriver do not over tighten FUEL FILTER SCREEN CARBURETOR sarery WARNING Exercise care to prevent fuel spillage in removing fuel line when engine is hot The carburetor f
10. Figure 7 27 Figure 7 28 Figure 7 26 ADVANCE TIMING CHECK Connect timing light to battery Clamp timing light electronic pickup to one high tension lead Run engine at idle speed 1300 1600 RPM and aim timing light at timing slot The advance yellow fin should be visible in the timing slot See Figures 7 26 and 7 27 CHARGE AND ALTERNATOR SYSTEM REPAIR REMOVAL Remove starter assembly outer fan housing breather from buretor cover from top of ignition coils engine cover and bracket and power pack cover Remove three screws attaching ratchet and ratchet mount to flywheel see Figure 7 29 Remove ratchet mount Remove flywheel nut see Figure 7 30 Use spark plug wrench handle in hole on rim of flywheel to keep flywheel from turning while removing nut Remove belt on electric start models Remove flywheel from crankshaft see Figure 7 31 using flywheel puller Special Tool 378103 Charge coils alternator coils and sensor coils are now accessible for servicing see Figure 7 32 _ 1 a 7 zm he fe Mus A gt ON lio Figure 7 29 Figure 7 30 The wave washer and rotor can now be removed See Figure 7 34 Remove 4 screws holding alternator and charge coil assembly to stator plate Assembly can now be removed from stator Figure 7 32 Sensor coils can now be removed for replacement if necessary h
11. Flywheel loose Crankshaft end play excessive L Carbon in combustion chambers and exhaust ports or On pistons e Worn or loose bearings or pistons Loose assemblies bolts or screws g Manual starter not centered Excessive fuel consumption a Hole in fuel pump diaphragm b Carburetor casting porous c Deteriorated carburetor caskets d Carburetor improperly adjusted e Hole in metering diaphragm Vibrates excessively or runs ro a Too much lubricant mixed with gas b Idle or high speed needles too rich Air passage to carburetor obstructed d Faulty ignition No power under heavy load a b Faulty carburetion Faulty ignition coil s Ignition timing off Carbon build up on piston head exhaust ports or exhaust system Cylinder scored or rings stuck Compression relief valve open High speed adjustment lean Spark plugs fouled or misfiring 7 Engine misfires Spark plugs dirty fouled Grounding or leakage of secondary leads Ignition coil faulty Grounding or leakage of ignition switch switch wire or connection Loose connections at ignition coils charge coils Power Pack I and sensor coils Spark on only one cylinder b Ignition coils Power Pack I output Engine wili start and idle but quits on accei erating a Check advance sensor coil and leads b Check Power Pack 1 output Check timing SECTION 5 TUNE UP PROCEDURES
12. If spark is strong and steady check leads going to ignition switch for grounds and check ignition switch Test 2 REPLACE GROUND WIRE ADVANCE CHARGE AND NUT AFTER SENSOR COIL REMOVING COVER COIL f ADVANCE TA X RETARD RETARD SENSOR IGNITION SWITCH POSITION NEEDLE POINT SPARK CHECKER 1 2 GAP Figure 7 18 Figure 7 20 TEST 7 ADVANCE SENSOR COIL RESISTANCE CHECK An engine that will start and idle but dies out when accelerating and with timing light connected will show the red fin retard timing mark and not the yellow fin advance timing mark when running has a bad advance sensor or Power Pack I If previous tests on the Power Pack I were positive a resistance check of the advance sensor coil should be made A Remove the white black stripe lead from terminal 8 of the Power Pack I the black white stripe lead from terminal 7 and the white green stripe lead from terminal 6 Check for 14 to 16 ohms re sistance between leads 7 and 78 See Figure 7 19 If sensor coil resistance does not come within these tolerances it must be replaced B Coil or leads must not be shorted to ground On ohmmeter hi ohms scale check for reading of infinity from either coil lead to ground If there is a leakage to ground check coil and leads and insulate area of leakage with tape TEST 8 RETARD SENSOR COIL RESISTANCE CHECK An engine that is hard starting ki
13. Ius 7 11 CHARGE AND ALTERNATOR SYSTEM REPAIR 7 18 29 2 55 wee 67 Amo ee 7 19 HE WSR ERE 25 bey BO Wa Abe 1 13 TENET ICN PIMC EA p a uU wh Wr 08 7 14 SPARR ETE nod ais alsch Bos e eom mis ad ee E ac Bea te ahd d eain 220496 1 16 CUM TRE NAP IDEO SUP Pep 1 16 SPECIFICATIONS al vs Ji dala sa caw T19 REMOVAL AND INSTALLATION 2 22 22 2 2 2 2 2 1 16 eit aru e Qa Mov ene te Le Ve eas PLNS S NUM 1 17 BATPEAY CARE 2 4 uy Q2 ale lod a DO KE ep nob abo eie d un d 3 1 17 BATTERY TESTING BERN 1 18 BATTERY CHARGING sha las Ba A a ala rar ala d Siow CHARGING re ERG E x 1 18 TARRANT La sat Pih 1238 STARTER Gone FA Asunt ie Ee ES oe 7 19 wate aos acer ome qw 7 19 MAINTENANCE Ces me Sri POR ATA 9 7 19 STARTER SYSTEM TESTING
14. CH oe CO LO 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 Being able to locate the cause of trouble in an improperly operating snow machine is as important as being able to correct the trouble A systematic approach to trouble shooting is important if the trouble is to be located and identified in minimum time Any service operation can be broken down into three steps 1 Identifying the problem 2 Determining the cause of the problem and 3 Correcting 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 mixtures compression ignition and proper drive system adjustment Engine theory compression carburetion ignition and power flow are discussed in Section 3 Correct fuel mixture for this snowmobile is outlined on the inside front cover and fuel blending is discussed in Sec tion 12 Familiarity with factors which contribute to abnormal per formance of an engine are similarly helpful The skilled mechanic s experience is a great asset here TROUBLE SHOOTING PROCEDURES Trouble shooting to determine the cause of any operating problem may be broken down into the fol lowing steps a Obtaining an accurate descri
15. Engine must be at normal operat ing temperature when test is made b Ground spark plug high tension leads so that engine can be cranked without firing c Connect a voltmeter across starter motor see Figure 7 47 with positive 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 C 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 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 Test 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 48 b 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
16. TO MAINTAIN ADEQUATE CYLINDER LUBRICATION THE HIGH SPEED NEEDLE VALVE SHOULD NEVER BE LESS THAN 1 1 4 TURNS OPEN LEANING OUT OF THE HIGH SPEED NEEDLE VALVE WILL RESULT IN SERIOUS DAMAGE TO THE ENGINE 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 care fully The correct high speed needle valve setting is obtained as follows 1 Turn high speed needle valve in until lightly seated Back out counterclockwise 1 1 4 turns See Figure 5 5 2 Start engine and allow warm up time of 3 4 minutes Turn choke lever to open position 3 Drive snowmobile at full throttle to observe engine performance 4 Open high speed needle 1 8 turn counterclockwise 9 Repeat steps 3 and 4 until engine begins to loose power slightly or 4 cycles loads up and fires on every other revolution 6 From this setting turn high speed needle in 1 8 turn clockwise Drive snowmobile at full throttle to observe engine performance j E 8 Repeat steps 6 and 7 no more than is necessary to obtain smooth performance and maximum power COMPRESSION COMPRESSION RELEASE VALVE COMPRESSION RELEASE ADJUSTMENT Ficure 5 4 HIGH SPEED NEEDLE VALVE Figure 5 5 5 5 LOW SPEED NEEDLE VALVE 87 Figure 5 6 27057 PULL COVER STRAIGH
17. front and rear truck axles Application of a light oil on the axles will assist in this procedure Apply OMC Part No 262233 grease under nylon bushings and assemble to pivot axles Assemble hanger and truck axle assembly to pivot axle Assemble pivot arms and springs See Figure 11 8 line up with each other Observe ARNING on Page 11 4 Drive roll pins in sprockets ress bearings on axle Apply a light oil to seals and assemble to front axle Seat seals after axle is assembled to chassis Assemble drive sprockets to front axle Fingers on sprockets must serve A F Assemble wheels bearings bearing retainer retaining ring pivot arms and brackets to rear axle Use a clean light oil to assist in this assembly Observe WING on Page 11 4 Apply OMC Screw Lock Part No 384848 to set screws before in Stalling Note pads in axle for seating set screws Apply OMC Part No 262233 grease to pivot arm bushings before assembly Assemble idler wheels to shaft Assemble trucks front and rear axle assemblies and idler assembly inside truck and install to snowmobile chassis The rear spring is loose when installing front and rear axles to bearing cups Before adjusting track tension place Spring arms inside Spring tabs See Figure 11 9 Adjust track tension as described on Page 11 3 Install spacer drive chain sprocket and cotter pin on front axle and replace drive chain See Page 10
18. TABLE OF CONTENTS e s ote a 2 2 FACTORS AFFECTING PERFORMANCE 9 2 FUEL SYSTEM E Ded IGNITION SYETEBN oe iue OR o gt 9 2 COMPRESSION TIPP 5 2 NEW VEHICLE DELIVERY 5 3 TUNE UP PROCEDURES 46434929 9 3 COMPRESSION CHECK 5 5 IGNITION TIMING CHECK 4 4 9 9 COMPRESSION RELEASE VALVE ADJUSTMENT TIPP I 5 5 CARBURETOR ADJUSTMENTS 5 5 HIGH SPEED NEEDLE VALVE 2 5 LOW SPEED NEEDLE VALVE 2 6 IDLE ADJUSTMENT SCREW 2 6 5 2 DESCRIPTION The purpose of a tune up is to restore power and performance which have been lost through wear or deterioration of 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
19. The electrical system consists of the alternator coils headlamp taillamp stoplamp ignition switch kill button dimmer switch wiring storage battery electric starting motor starter solenoid and rectifier The alternator coils produce alternating current which changes in frequency and voltage in proportion to engine speed This alternating current output is rectified changed to direct current by a full wave diode bridge rectifier and used to charge the battery Direct current is then used to power the headlamp and taillamp and the electric starter motor See wiring diagram at the end of manual This section gives complete service procedures on all components of the ignition and electrical systems Principles of the C D capacitor discharge ignition system are discussed in Section 3 TEST EQUIPMENT The test procedures outlined in this section require the use of the following equipment 1 Multimeter see Figure 7 2 ohmmeter or volt ohm ammeter See Figure 7 10 2 Needle point spark checker gap set to 1 2 See Figure 7 3 3 Neon test light M 80 Figure 7 4 or 5 80 Figure 1 5 4 Externally powered timing light with electronic pick up See Fig ure 7 6 5 Ignition coil analayzer See Figures 7 17 7 8 and 7 9 DO NOT use a test instrument having more than a 12 volt source to check rectifier diodes Figure 7 4 Figure 7 5 1 3 ELECTRONIC PICK UP GRAHAM Figure 7 6 Figure 7 7
20. A neutral control mechanism is used to prevent the drive from engag ing 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 control will operate only when the engine is at idle speed SECONDARY DRIVE The secondary drive mechanism incorporates a torque sensing device that detects the need for more power for steep inclindes or deep snow The mechanism immediately forces the secondary sheaves closer to gether to increase the drive ratio and provide a higher torque to the drive chain and track The drive ratio varies from 3 3 to 1 in low to 97 to 1 in high which yields an overall drive range of approximately 3 33 tel Poweris transmitted from the secondary sheave assembly through a drive chain to the front axle The ratio between the secondary sheave and the front axle is 16 30 An optional upper sprocket is available to change this ratio to 18 30 for higher speed driving SECTION 4 TROUBLE SHOOTING TABLE OF CONTENTS bo DESCRIPTION ace ae eet agi pav av TROUBLE SHOOTING PROCEDURES SDAIN wy STARTING MANUAL STARTER STARTING ELECTRIC STARTER RUNNING LOW SPEED ONLY RUNNING HIGH SPEED
21. Pull chain case away from fixed face and shaft 15 13 Remove eccentric 17 14 Remove O ring 16 15 Remove seal 18 and cone 21 from eccentric 16 Press cups 19 from eccentric Figure 10 16 10 8 17 Remove secondary drive 18 See Figure 10 16 for following steps Remove retaining ring 1 from fixed face and shatt 15 19 Remove end cap 3 spring 4 and key 5 CLEANING AND INSPECTION 1 Clean bearing in trichloroethylene see SAFETY WARNING on page 9 6 2 Check bearing for wear or roughness 3 Check shaft sheaves woodruff keys and Delrin ramp shoes item 20 for excessive wear REASSEMBLY 1 Assemble movable half of sheave see Figure 10 16 1 3 4 14 and 20 to shaft 2 Press bearing cups into eccentric 3 Grease inner bearing cone with OMC no 114154 grease and install on shaft 4 Install seal NOTE A new seal must be used if shaft was pressed from eccentric 5 Insert woodruff key in shaft 6 Engage spring ends in holes in movable sheave and end 1 Preload spring by holding end cap stationary and rotating movable sheave clockwise to engage next ramp on end cap approximately 1 3 turn 8 Compress spring to allow installation of end cap retaining ring 9 Replace retaining ring 10 Assemble fixed face and shaft into chain case 11 Assemble eccentric to shaft through drive sprocket side 12 Replace eccentric adjusting bolt 13 Reins
22. assured if a complete tune up is performed at least once each year preferably 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 preformance 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 stale fuel mix ture may cause hard starting stalling and faulty operation Inadequate fuel delivery as the result of a 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 See Section 3 for a dis cussion on carburetion IGNITION SYSTEM A good ignition system is of prime importance for peak engine per formance A weak spark which may be the result of faulty ignition system components will cause hard starting misfiring or poor high speed performance The spark plugs and ignition system components are frequently checked first in a tune up beca
23. neutral control knob out to lock transmission in neutral Ac celerate engine to see if transmission is in neutral Neutral control cannot be engaged above approximately 2000 rpm Check compression see page 5 5 If engine knocks check for loose flywheel Remove manual starter and fan housing see Section B 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 puling on flywheel End play tolerance should not exceed 019 If excessive end play is suspected remove carburetor and leaf valve assembly If motion between main bearing outer race and crankcase is detected engine must be overhauled both compression and bearing condition checks are not satisfac tory engine overhaul is required see Section 9 Test ignition system using Spark checker and neon C D Tester Inspect 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 Remove and drain fuel tank flush and clean thoroughly 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 screen behind carburetor fuel inlet elbow Thoroughly lubricate snow machine see Section 12 Tighten all e
24. 2 20 3 8 16 5 16 24 5 8 18 3 8 16 3 4 16 5 16 24 3 8 16 5 16 18 3 8 24 3 8 24 5 16 18 3 8 24 5 16 24 3 8 16 7 16 14 3 8 24 6 8 410 12 1 4 5 16 PART APPLICATION TORQUE LBS LBS 1 10 15 22 25 35 35 40 60 80 120 140 Screw 3 8 220 240 18 20 Specifications and features may be changed at any time without notice and without obligation towards vehicles previously manufactured Use Torque Wrench SECTION 3 GENERAL SNOWMOBILE INFORMATION TABLE OF CONTENTS TWO CYCLE ENGINE OPERATION 3 2 COMPRESSION 3 242 3 2 CARSUEETIUON qe 2 RA aS 3 3 IGNITION 9A 4 2 3 4 LIGHTING SIL 2 lt Uwe pud 3 4 POWER FLOW wa as Saas ea 3 5 PRIMARY 3 5 802 3 6 POWER STROKE DOWN COMBUSTION OF FUEL AIR MIXTURE ROD AXIS OF ROTATION Figure 3 1 FUEL INTAKE AND EXHAUST LEAF VALVES CLOSED INTAKE PORT OPEN PORT OPEN Figure 3 2 COMPRESSION STROKE UP LEAF VALVE FUEL FROM OPEN CARBURETOR INTAKE PORT EXHAUST 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 withi
25. 5 SECTION 12 LUBRICATION AND STORAGE TABLE OF CONTENTS ENGINE LUBRICATION dam sae 2 4 FUEL CONDITIONER FUEL BLENDING LUBRICATION RECOMMENDATIONS PREVENTIVE MAINTENANCE AIR FUEL FILTER SCREEN FUEL PUMP FUEL FILTER SCREEN CARBURETOR 4 STORAGE 44 PREPARATION FOR STORAGE REMOVAL FROM STORAGE 12 1 12 2 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 the mixture of lubricant and gasoline enters the crankcase the gasoline 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 In 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 The use of too little lubricant leads to premature wear and early break down A fuel mixture richer in lubricant than recommended is not only wasteful but will contribute to faulty performance and to excessive carbon accumulation in
26. C D IGNITION SYSTEM TROUBLE SHOOTING INTRODUCTION An understanding of the theory of the C D ignition system is an in valuable asset in following the C D ignition trouble shooting procedure See Section 3 for a discussion of the C D ignition theory the following tests can be conducted without the removal of the flywheel C D IGNITION SYSTEM DO S AND DONT S 1 Do make sure that all connections are clean and tight especially ground connections Poor connections mean problems 2 Do make sure that all plug in connectors are fully engaged and free of corrosion Loose or corroded connectors mean problems 3 Do make sure that all wiring is located properly so there is no chance of rubbing against any edges that can cause wear and insula tion breakdown This can create a difficult service problem 4 Do make sure test equipment is in good working order before troubleshooting the system Poor test equipment will not solve a problem 2 When connecting neon test light lead to Power Pack I be sure to use spade terminal to ensure good connection 9 Do use proper tools when working on system components Wrong tools could damage components A SAFETY WARNINGS 6 AND 7 6 Do return key switch to OFF position after each test before touch ing any system leads This will discharge capacitorin Power Pack I and prevent a possible high voltage electric shock 1 Don t hold spark plug wires in your hand while checking for sp
27. Owner s Manual e Be sure that the customer understands how to operate the engine correctly especially such things as the neutral control compres sion release choke and electric starting TUNE UP PROCEDURES Components which affect engine power and performance can be divided into three groups namely 1 items affecting compression 2 items affecting ignilion 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 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 Test run vehicle checking particularly the following 1 Neutral control Can transmission be locked in neutral when machine is at rest and engine at idle speed 5 3 5 4 E 2 Function of compression release 3 Function of brake 4 Engine performance 5 Ski alignment and handling 6 After running snowmobile reduce engine speed to idle and pull
28. Remove two screws and sensor plate assembly can be removed See Figure 7 33 REASSEMBLY a Install sensor plate assembly and sensor coils Important Leads must be secured properly to prevent pinching or chafing b Install rotor and wave washer Check for 010 gap between rotor and sensor coils Use a 010 diameter wire or 010 plastic gauge Special Tool 4604659 only as a flat metal feeler gauge will not fit curvature See Figure 7 34 Adjust if necessary by loosen ing screws securing the coil Torque sensor screws 12 16 inch pounds ALTERNATOR COILS ALTERNATOR COILS Figure 7 34 Figure 7 35 Figure 7 37 L e Install alternator and charge coil assembly d Install flywheel See Figure 7 35 e Place washer and flywheel nut in position Hold flywheel with bar and torque flywheel nut to 40 45 foot pounds See Figure 7 36 f Reassemble remaining parts in reverse order of disassembly ws FLYWHEEL NUT TO 40 45 FT LBS mer Cm 8 T 2 4 LI Figure 7 36 IGNITION TIMING Ignition timing is fixed Therefore if timing is found to be off in test 11 either the sensor lead wiring to the Power Pack I is switched or the sensor hub key is sheared or missing 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 c
29. SPINDLE NE F screw SCREEN SPRING Ficure 6 1 8 3 CLEANING INSPECTION AND REPAIR a Wash metal components in solvent and blow dry with compressed air b Inspect spring for broken end loops or insufficient tension c Examine starter pawls and ratchet for excessive wear d Inspect friction ring and spring spindle bushing spindle and re tainers e Inspect rope and discard if frayed Replace with starter rope cut length of 73 3 4 inches f Examine pulley and housing rope eye for sharp edges and rough surfaces that might cause rope fraying File and polish as neces sary REASSENMBLY a Wind starter spring using Fixture Base Special tool 383966 Figure 8 2 b Place outside spring end loop on starter housing anchor pin c Replace starter pulley with inside spring end loop fitted on starter pulley pin d Grease hub of pulley before installing bushing e Grease inside of bushing and install spindle spring washer and friction ring in bushing Fasten with screw washers and nut f Wind pulley counterclockwise until tight g Unwind pulley clockwise until pulley anchor hole lines up approx with starter rope hole in starter housing Lock starter pulley in position by aligning holes in pulley and housing and inserting a nail or pin through them i Tie a knot in one end of starter rope If installing a new rope be sure length measures 73 3 4 inches Fuse nylon strands over a
30. are two sensor coils Below the idle RPM range and up to approximately 900 RPM the retard sensor turns on the electronic switch in the Power Pack 1 At RPMs over 900 the advance sensor coil generates enough voltage to turn on the electronic switch in the Power Pack I before the retard sensor does S80 we have an automatic electronic advance built into the system The ignition coil primaries receive the voltage from the Power Pack 1 building up the secondary voltage high enough to fire across the spark plug gaps LIGHTING SYSTEM The alternator coils produce alternation current which changes in frequency and voltage in proportion to the engine speed This alternating current output is converted to direct current by a diode bridge rectifier and used to charge the battery Direct current from the battery is then used to power the headlights and taillights and the electric starter motor The alternator output is automatically increased to maximum charge when lamps are turned on 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 transmission belt PRIMARY DRIVE The primary sheave is centrifugally operated and engages the trans mission belt
31. assembly See Section T MAG NETO AND ALTERNATOR REPAIR f Remove compression relief valve g Remove spark plugs h Remove engine from frame i Remove exhaust manifolds from cylinder barrels if maintenance is necessary j Remove cylinders and crankcase group from engine frame as sembly Before performing next step take note that cylinders must be replaced on side of crankcase from which they were removed Remove the eight cylinder stud nuts and lockwashers Thecylinder barrels can now be removed from the crankcase See Figure 9 7 If itis necessary that only the cylinders and pistons be serviced this can be aecomplished with only the cylinder barrels removed 9 4 p CYLINDER STUD NUTS Figure 9 7 l Remove screws from crankcase halves and drive out two align ment roll pins Heat up crankcase halves in bearing area to ap proximately 250 F IMPORTANT when heating crankcase be careful not to damage seals Tap crankcase with rawhide mallet to break seal and separate crankcase halves See Figure 9 10 NOTE Pistons connecting rods and caps are matched parts and seat with the operation of the engine Because of 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 m Remove connec
32. b Assemble the new strap around the fuel line with the serrated side toward the inside See Figure 6 11 Snug up the head on the strap See Figure 6 12 Tighten head on strap with pliers as illustrated in Figure 6 13 d Figure 6 11 Figure 6 12 Figure 6 13 1 1 SECTION 7 IGNITION AND ELECTRICAL SYSTEMS TABLE OF CONTENTS HRSCHUPTSON Aag 7 2 TEST EQUIPMENT wa intaia paiva iaai Ari C D IGNITION SYSTEM TROUBLE SHOOTING 4552 x 71 5 xeu 5 vasis Tod DOS ANTONIUM AL pu sum NA E s d Cah ee ory x TEST 4 IGNITION COILS OUTPUT CHECK cix in 1 4 TEST 42 IGNITION SWITCH CHECK v fa af ER wits Ka e do a m e a i 1 5 TEST 3 CHARGE COIL OUTPUT CHECK 2 4 7 6 TEST 4 RETARD SENSOR INPUT CHECK T TEST 5 POWER PACK TOUTPUD CHECK TEST 6 IGNITION SWITCH CONTINUITY GROUND CHECK 7 9 TEST 7 ADVANCE SENSOR COIL RESISTANCE 7 10 TEST 8 RETARD SENSOR COIL RESISTANCE 7 10 TEST 9 CHARGE RESISTANCE CHECK cadence 7 10 TEST 10 IGNITION CONTINUITY POWER AND INSULATION CHECKS 1 10 TEST 11 IGNITION TIMING CHECK 2 222 22 4 4
33. 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 a new gasket Do not force the cage as 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 Remove and inspect the points of the high speed and low speed Figure 6 2 needle valves Through misuse either mixture screw point may be bent extruded from being forced into the casting seat or possibly broken off in the casting see Figure 6 3 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 screen 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 parts 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
34. crankshaft throw ASSEMBLY OF ENGINE Refer to Parts Catalog exploded views for correct sequence of as sembly 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 Per fectly 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 sur faces cylinder walls etc with clean oil before assembly NOTE Use new gaskets and seals throughout when reassembling the engine Apply OMC Gasket Sealing Compound 7317201 to both sides of crankcase gasket before assembly PISTONS WRIST PINS AND CONNECTING RODS NOTE Pistons are not interchangeable with one another The wrist pin hole is offset in different directions Piston Identification Piston Stamped No 1 on head place in front cylinder nearest bumper Piston Stamped No 2 on head place in cylinder nearest driver a Install wrist pin needle bearing in connecting using an arbor press b Apply a coat of oil to wrist pin making sure that 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 ap proximately 140 F Insert wrist pin through hole in one side of piston Place connecting rod in position in piston the
35. gap See Figure 7 11 Crank engine with electric starter or manual starter with ignition switch in position Remove plugs for easier cranking 1 Strong steady spark from both coils system is good REPLACE GROUND WIRE ADVANCE CHARGE AND NUT AFTER SENSOR COIL REMOVING COVER POWER PACK 1 Lm ADVANCE COMMON seram RETARD SENSOR COIL NEEDLE POINT SPARK CHECKER 1 2 GAP Figure 7 11 2 Weak erratic or no spark from one ignition coil switch ignition coil leads on Power Pack I repeat test Spark on same cylinder still erratic replace coil Spark on opposite cylinder erratic replace Power Pack I TEST 2 IGNITION SWITCH CHECK Disconnect orange black lead from Power Pack terminal 5 See Figure 7 11 With ignition key in RUN position check from orange black lead to engine ground with ohmmeter set on Hi ohm scale There should be no reading or infinite reading on meter indicating ignition switch not shorted and lead not grounded C If less than 500k ohm reading remove terminal connectors from ignition switch see Figure 7 12 and remove ignition switch from dash panel Turn ignition key to RUN position and take a resist ance reading across the magneto and ground terminal of the ignition switch See Figure 7 13 D If infinite reading indicated find problem in orange black stripe lead E less than 500k ohm reading indicated replace ignition switch F Reconnect
36. key switch lead to terminal 5 on Power Pack I CONNECTORS 1 LI LIGHTS IGNITION MAGNETO SWITCH GROUND Figure 7 12 Figure 7 13 OFF POSITION RUN POSITION The magneto terminal GNETO and ground terminal are connected together GROUND LIGHTS FRUN POSITION START POSITION BATTERY BATTERY The battery and lights LIGHTS terminals are connected together The A and Y terminals are connected together IGNITION SWITCH INTERNAL CONNECTORS Figure 7 14 7 5 No ignition switch ter minals connected together The start and battery terminals are connected together TEST 3 CHARGE COIL OUTPUT CHECK A Remove charge coil brown white stripe lead from Power Pack terminal No 1 B Use Neon tester 580 or M80 Connect neon tester black lead to charge coil brown white stripe lead and tester blue lead to engine ground See Figure 7 15 Set neon tester rotary switch to position 2 Depress load button D Crank engine with electric starter or manual starter with ignition switch in RUN position and observe neon tester light 1 If light is bright and steady charge coils are good Check Power Pack I output Test 5 2 If light is intermittent or no light check for grounding or open leads to charge coils Also check charge coils for correct resist ance Test 9 Reconnect charge lead to terminal 1 on Power Pack 1 REP
37. or 9 foot pounds and current should be a maximum of 405 amperes If motor smokes or gets hot instantly stop testing disassemble starter and check for shorts Use only a fully charged 12 volt battery when making stalled torque test Obtain readings as rapidly as possible to prevent starter overheating Allow suffi cient time for starter to return to room temperature if it is necessary to repeat stalled torque test C Check each armature coil for open circuits by rotating torque wrench handle through a 180 degree arc 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 Check armature on growler for shorted turns see Figure 7 51 NOTE Follow operating instructions furnished with armature growler for proper test procedures Clean between commutator segments of armature and recheck armature on growler If shorted turns are still indicated replace armature Check armature for grounded windings see Figure 7 52 Rotate one lead of continuity tester test light or meter around circum ference of commutator while holding other continuity meter leads on the armature core or shaft An indication of continuity means t
38. to prevent this damage Disconnect one of the battery leads before charging battery If storage temperature is hot more frequent charging will be necessary Add water if neces sary before charging to bring electrolyte toproperlevel Fully charged batteries have been known to withstand temperatures as low as 90 F a discharged battery will freeze at about 19 F perhaps causing burst ing of both the cell and battery cases BATTERY TESTING Make sure battery is fully 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 electrolyte 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 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 SAFETY WARNING Gases given off by a battery being charged or jumped are highly explosive Keep battery in a ventilated area and away from cig arettes and open flames when charging or jumping Turn off battery charger before removing cables from battery Remove cables from good battery first when jumping For best performance a good battery should be fully charged bef
39. when the engine speed reaches 2500 to 2800 rpm When the engine is rotating at idle speed orbelow 2500 to 2800 rpm the trans mission belt rides on a ball bearing between the halves of the primary sheave assembly see Figure 3 8 The primary sheave assembly halves are separated by a compression spring in the hub of the movable sheave half 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 on a larger diameter of the primary sheave assembly increasing belt speed see Figure 3 9 Since the belt length remains constant the secondary sheave halves spread apart allowing the belt to ride on a smaller diam eter 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 Balls Grease Fitting End Cap Assem Garter Activating PRIMARY SHEAVE ASSEMBLY 37028 Idler Ball Bearing Compression Spring E Movable Half of Sheave F Belt KNOB IN G Fixed Half of Sheave NEUTRAL H Neutral Lockout LOCKOUT Plunger POSITION 1 Crankshaft J K Figure 3 8 1 NT DRIVE POSITION BELT ENGAGED PRIMARY SHEAVE ASSEMBLY Figure 3 9 37028 3 6 NEUTRAL CONTROL
40. ADJUSTMENT Total slack must be 1 4 1 16 as shownin Figure 10 10 To measure this distance first remove the chain case cover Note Oil will drain when cover is removed unless snowmobile is tilted on its side Place a straightedge over the chain at the sprockets press in on the center of the chain and measure the slack at this point If the chain requires adjustment use the following steps 1 Loosen adjusting screw locknut see Figure 10 11 2 To tighten chain pivot the eccentric adjustment downward 3 To loosen chain pivot eccentric adjustment upward LUBRICATION The drive chain is lubricated by oil in the chain case Should it be necessary to add oil use only OMC Type C and follow these instruc tions Remove rubber plugs top and bottom Pour oil in top hole until it reaches level as shown in Figure 10 9 It will hold approximately 4 oz Replace plugs BRAKE DESCRIPTION The brake is positive acting disc type with long lasting fibre pads pucks REMOVAL Loosen brake adjustment nut See Figure 10 12 b Remove brake control cable from actuator cam arm 10 5 SPROCKETS H Figure 10 10 ADJUSTMENT CHAIN ADJUSTING SCREW LOCKNUT Figure 10 11 10 6 BRAKE ADJUSTMENT NUT ACTUATOR CAM ARM BACKUP WASHER BRACKET MOUNTING BRACKET Was QUICK DISCONNECT Figure 10 13 d Remove brakelamp plunger spring from actuator cam arm See Dis
41. Assemble needle bearing 16 and retainer halves with connecting rod and connecting rod caps NOTE Connecting rod caps are matched Do not interchange connecting rod caps or turn them end for end c Assemble piston and rod assembly to crankshaft with piston ring dowel pins facing top of engine Attach caps to connecting rods d Draw sharp pencil down four machined corners of connecting rod and cap assembly to ensure proper alignment See Figure 9 21 If not aligned offset edge will be felt with pencil point If align ment is necessary tap into alignment with drift punch If align ment is satisfactory tighten connecting rod cap screws to specified torque NOTE It maybe necessary to heat crankcase halves for easier in stallation of crankshaft e Spread film of OMC Gasket Sealing Compound 317201 to both sides of gaskets f Insert screws and finger tighten Insert roll pins locate and drive in Torque bolts to 1 2 required torque 2 3 ft lb Final torque bolts to 5 7 ft lb Trim gasket material from open areas of crankcase Check crankshaft end play It should not exceed 019 9 10 h Crankshaft tapered end must be kept clean free of grease and fingerprints before installation of primary sheave assembly 1 Install crankshaft seals in crankcase CYLINDERS a Install cylinders using new gaskets Use a ring compressor Special tool 426020 to install pistons in cylinders Tighten nuts in correct seque
42. Compression leakage will occur if the compression relief valve link age is adjusted with insufficient clearance on the cable ends The relief valves vent combustion chamber pressure through a by pass port Compression may also be affected by the fuel induction and exhaust systems Since the fuel vapor is first compressed in the crankcase 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 cylin der walls can result in a loss of power Following the trouble shooting procedures in Section 4 and the recom mended tune up procedures viven in Section 5 will assure that all areas affecting fuel induction compression and exhaust will be considered as part of every trouble shooting procedure An engine with low or uneven compression cannot be successfully tuned for peak performance is essential that improper compression be corrected before proceeding with an engine tune up CARBURETION Gasoline in its state burns relatively slowly with an even 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 b
43. ECTRICAL 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 manual together with the regularly issued service bulletins and Parts Catalogs provide the serviceman with all the literature necessary to service this snowmobile An effort has been made to produce a manual that will not only serve as a ready reference book for the ex perienced serviceman but will also provide more basic information 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 as a 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 th
44. IATELY flush the exposed area with liberal amounts of water and obtain medical aid as soon as pos sible 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 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 42 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 and inspecting for low electrolyte level If battery shows signs of serious damage or abuse it should be replaced Visually inspect the battery for the following 1 Corrosion 2 Frayed or broken cables 3 Cracked case or cell covers 4 Loose hold down clamps 9 Low or overfilled electrolyte BATTERY CARE Check the following at regular intervals CHARGED DISCHARGED 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 2 Keep battery terminal connections tight and free from corrosion If corroded clean cable terminals and bat
45. LACE GROUND WIRE ADVANCE CHARGE SET NEON AND NUT AFTER SENSOR COIL LIGHT TO 2 DEPRESS REMOVING COVER LOAD POWER BUTTO ADVANCE a mETARD 2 i SENSOR COIL NEEDLE POINT SPARK CHECKER 1 2 GAP Figure 7 15 TEST 4 RETARD SENSOR COIL INPUT CHECK Connect needle point spark checker as illustrated See Figure B Remove retard sensor white green stripe lead and advance sensor lead white black stripe from Power Pack terminals 6 and 8 Do not allow leads to touch ground See Figure 7 16 C Connect neon tester S80 or M80 black lead to Power Pack terminal 6 and blue lead to sensor common terminal 7 Set rotary switch to position 3 See Figure 7 16 D Crank engine with electric starter or manual starter with ignition switch in RUN position and at same time rapidly tap neon tester load button 1 If there is spark across both gaps check retard sensor leads and check sensor coil for correct resistance Test 78 2 If there is no spark on both coils go to test 3 If there is no spark on one coil go to test 10 E Reconnect sensor leads 6 and 8 on Power Pack I ADVANCE CHARGE REPLACE GROUND SENSOR WIRE AND NUT AFTER SET NEON PACK 1 REMOVING COVER TAP LOAD BUTTON ADVANCE COMMON SENSOR COIL NEEDLE POINT SPARK CHECKER Figure 7 16 TEST 5 POWER PACK I OUTPUT CHECK A Remov
46. LY 1 Reassemble in reverse order first making sure mating surfaces are clean and smooth 10 1 SECTION 10 DRIVE TRAIN TABLE OF CONTENTS 10 2 TRANSMISSION BELT INSPECTION AND 10 2 REMOVAL 10 2 REPLACEMENT 4 10 2 PRIMARY 4 10 3 REMOVAL 4 10 3 DISASSEMBLY 444255454493 10 3 CLEANING INSPECTION AND REPAIR 10 3 4 10 4 10 5 LUBRICATION 10 9 X ovg ce ree se wee mor 10 5 REMOVAL c2222252222223 10 5 10 5 REPAIR 10 5 EN 10 5 DESCRIPTION l qva 10 5 REMOVAL iua 10 5 REPAIR 4 4 10 6 BRAKE CABLE amp ASSEMBLY 10 6 10 6 SECONDARY DRIVE 10 7 DISASSEMBLY is cue ete ns en ee 10 7 CLEANING AND INSPECTION 10 8 REASSEMBLY 10 8 10 2 DESCRIPTION This section gives complete service instructions on the snowmobile drive train A brief discussion of the power flow system is included i
47. N Yellow lead termi nals must be insulated from ground before starting machine Wrap terminals in electrical tape or other suitable material to insulate DESCRIPTION The battery s primary function is to provide power to Operate the starting motor however the battery also supplies power to operate the lights when the engine is not running at higher speeds The storage NIPPLES CAN BE INTERCHANGED battery is a secondary chemical generator one that produces DEPENDING ON BATTERY 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 a case to make up a 12 volt battery NIPPLE NIPPLE HOLE Figure 7 42 SPECIFICATIONS Due to the extreme weather and temperature conditions under which the battery must operate proper battery selection is 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 recommende
48. 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 Connect starter with an ammeter in series to 12 volt source see Figure 7 49 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 after a very few seconds of running or gets hot instantly stop testing Disassemble starter and check for shorts Stalled Torque Test b Connect a voltmeter between the starter terminal and motor frame Using a torque wrench to stall motor armature see Figure 7 50 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
49. OR solvent such as Trichloroethylene see ASA WARNING page 9 6 and blow dry with com pressed air b Inspect main shaft and sheave assembly splines for wear c Align holes vertically in fixed shaft and sheave assembly neutral lockout balls should fall through holes freely 10 3 gt m um SERVICE TOOL 113971 Figure 10 2 SERVICE Ee TOOL 404032 1 End Cap and Pulley Assembly 2 Sliding Sheave 3 Fixed Sheave 4 Lock Plate 10 4 SERVICE TOOL 404032 Figure 10 6 10 4 MOVABLE HALF OF SHEAVE FF Figure 10 7 Figure 10 8 d Inspect neutral lockout plunger for wear Replace if required e Inspect transmission belt A glazed or burned belt or one meas uring less than 1 1 16 across width or outer surface must be re placed with a new one Worn belt should be returned to owner for use as spare A spare belt should be carried at all times REASSEMBLY NOTE Internal threads and taper on fixed shaft and sheave must be cleaned prior to reassembly When assembling fixed shaft and Sheave to crankshaft be certain that fixed shaft and sheave is securely tightened to crankshaft 1 Align holes in main shaft spline in horizontal plane Retain neutral lockout balls in holes with Part No 114154 grease 2 Place compression spring on shaft with closed side of spring cup toward bearing 3 Place movable half of sheave o
50. T OFF WITH SLIGHT TWIST SPARK mt PLUG Figure 5 7 NorTE THE HIGH SPEED NEEDLE VALVE SHOULD NEVER BE SET LEANER THAN 1 1 4 TURNS OPEN Two cycle engines are lubricated by oilthatis drawn into the crank case with the fuel charge Although they will start and run with a leaner mixture serious engine damage may result from too lean a setting A TOO LEAN A SETTING if engine misses backfires and runs rough Open high speed needle 1 8 turn more counterclock wise Repeat this test procedure until engine begins to 4 cycle loads up At this point turn high speed needle 1 8 turn in clockwise until smooth engine performance is obtained B TOO RICH A SETTING if engine 4 cycles loads up and fires on every other revolution Condition noticed also by a loss of power Turn high speed needle in 1 8 turn clockwise until smooth engine performance is obtained LOW SPEED AND IDLE ADJUSTMENT SCREW See Figure 5 6 1 Pre set low speed needle valve one turn open 2 Turn idle adjustment screw to the left counterclockwise until throttle plate is completely closed and screw is not in contact with throttle lever 3 Start engine and allow warm up time of 2 or 3 minutes If engine will not idle turn idle adjustment screw to right to keep engine running Turn choke lever to open position 4 Turn idle adjustment screw to attain the recommended idle speed of 1300 1600 rpm 9 Accelerate engine If a flat
51. a at ambient temperatures Under no circum stances should the solvent be 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 be free from carbon deposits to insure maximum performance Clean compression relief valve and check for free action NOTE DO NOT scratch gasket surfaces Scratches can cause com pression losses b 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 or cylinder is badly scored replace Major portion of wear will be in port area and area cov ered by ring travel GASKETS AND GASKET SURFACES a Discard all gaskets seals and O rings Use new gaskets and seals in reassembly b Remove all traces of dried cement and old gasket material using trichlorethylene or lacquer thinner Check gasket faces for flatness Under certain conditions gasket faceS May warp or spring particularly where thin sections or flanges are employed and are subject to temperature changes To check for flatness lay a sheet of No 120 emery cloth on a surface plate or piece of plate glass see Fi
52. ade care must be used when fastening terminals together If connectors are not as sembled 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 connec tions examine the terminals on both halves of the connectors after assembly to be sure that all terminal ends are in place If a 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 ALTERNATOR COILS The alternator coils are replaceable along with the charge coils as an assembly See Figure 7 55 The alternator coils can be checked for their correct resistance without removal of the flywheel as shown in Test 1 TEST 1 ALTERNATOR COIL RESISTANCE TEST Do not make resistance test at rectifier A Disconnect curved 3 way connector from alternator B Connect ohmeter one meter lead to yellow alternator lead the other meter lead to yellow gray stripe lead Resistance reading is 95 ohms Connect ohmeter one meter lead to yellow gray stripe lead and the other meter lead to greeen lead Resistance reading is 4 ohms D Connect ohmeter one meter lead to yellow lead and the other meter lead to green lead Resistance reading is 1 3 ohms TEST 42 ALTERNATOR COIL OUTPUT TEST A Remove yello
53. aillamp Stoplamp esses sse seres En d a te 24 GE 1157 Fuel Tank ie cw ps 5 4 Imperial gallons 6 5 U S gallons RiGee 3 6 brand 50 1 lubricant Carburetor Needle Adjustinent High speed wee eee es 1 1 4 turns off seat minimum oq x 1 to 1 1 4 turns off seat RPM Ratings avt wid aae 1300 1600 Transmission belt engaging speed 2500 2800 Maximum RPM at which neutral control will operate Approx 2000 Ignition Breakerless magneto C D Capacitor Discharge ignition Spark plug gt s is a ee 4 4 8 lt oe 4 EERE WE Champion Ud2d Spark plug gap eee 028 033 inch Advance sensor coil resistance 45 OY ee 44 18 Ohlins Retard sensor coil resistance 3 52 25 27 29 ohms Magneto charge coil resistance 2 coils total OF ve ss 860 10 ohms Ignition coil secondary resistance 1900 190 ohms Lighting coil resistance 3 1 0 Engine coil resistance 4 windings 9 osu 5 ohm Bore and stroke 497 2 3 4 x 2 1 4 inches Piston displacement 26 7 cubic inches 437 Compression ratio fuia
54. ains 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 Do not run the engine with the filter element removed REASSEMBLY a Reassemble the fuel filter Do not overtighten cap to fuel pump FILTER body FILTER CAP b Attach gasket and fuel pump to plate with screws Figure 6 8 c Reconnect fuel hoses and secure with new tie straps 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 1 b To check operation of the primer disconnect hose from manifold check valve A spurt of fuel should be evident when the plunger is depressed Tf little no fuel is discharged check the valves the fuel line and fuel line fitting for leakage or sticking refer to Figure 6 1 Check valve above fuel primer fitting must be in verticle position in order to operate AIR FILTER The carburetor is equipped with an automotive type paper air filter element that should be cleaned once during the operating season and replaced after a year s service When pores in paper are plugged engine will receive a rich fuel air mixture and run rough and get poor fuel economy To clean filter element shake to dislodge dirt par
55. ame amount of threads showing on each end of the tie rod when the skis have been adjusted anda minimum of 1 2 inch of thread in the ball joint should be main tained 1 Replace hood TRACK AND SUSPENSION TRACK TENSION ADJUSTNENT Do not run track dry Apply soap and water to inside of track to prevent damage Track tension must be checked after the first ten hours of operation and then every 25 hours as required to maintain efficient econom ical 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 arm is 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 1 4 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 See Figures 11 3 and 11 4 Turn pivot arm adjusting screw to obtain the correct 2 1 2 1 32 as shown in Figure 11 3 d Measure distance from front edge of adjusting bracket to anchor If this distance is not equal on both sides loosen the adjustment on the side nearest to the rear until the distance from front edge of the adjusting bracket to the anchor is equi
56. ances bend or flex the leaves by hand gt pe H 6 5 Carburetor Gasket Flange Gasket Throttle Shutter Carburetor Body Throttle Shaft Clip Return Line Elbow Return Line Screen Idle Speed Bracket Idle Speed Screen Throttle Shaft Return Spring Throttle Shaft Sleeve Idle 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 6 6 Clean inspect and immediately reassemble the leaf valve assem HOLE FOR INTAKE bly rather than leave it apart for reassembly later FUEL PUMP MANIFOLD The leaves are designed to maintain contact with the leaf valve PULSE GASKET body and to spring away from the leaf body when vacuum is ACTION applied Inspect leaf plate assembly and replace leaf valve body assembly if damaged f Check tightness of leaf valve retaining screws and tighten any that appear loose Tighten screws to torque specified in Section 2 INSTALLATION a Secure leaf plate assemblies to base using a new leaf plate gasket coated with Gasket Sealing Compound 317201 Align leaf p
57. ark A severe electrical shock could result Use insulated pliers de signed for this purpose 8 Don t remove potting compound from Power Pack as this will void any warranty 9 Don t pull on high tension leads at the ignition coils You might break the insulation or connection 37118 10 Don t open or close any plug in connectors while the engine is running You might cause damage to the system Figure 7 10 11 Don t attempt any tests other than those listed in the trouble shooting procedure You might cause damage to the system 12 Don t connect an electric tachometer into ignition system You might damage the system This does not include the electronic sensor type tachometers 13 Don t connect this sytem to any voltage source other than what is specified You might damage the system nore When connecting test equipment leads or reconnecting engine wiring leads to Power Pack I always refer to the diagram pro vided You must hook leads in correct location or possible damage to system will result When removing Power Pack I cover plate make sure you place it alongside Power Pack I in same direction it was removed This will assure correct terminal identification Also replace black ground wire and screw to Power 1 after cover is moved before conducting following tests TEST 1 IGNITION COILS OUTPUT CHECK A Pull high tension leads off spark plugs Connect spark gap checker with 1 2
58. cant 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 F Do not use kerosene or fuel oils for pr mixine 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 12 3 12 4 LUBRICATION RECOMMENDATIONS 37340 MAINTENANCE LUBRICANT Every 25 hrs Ski Pivots Leaf spring connections to skis SAE 10 Oil Once a season Ski columns grease fittings OMC Grease 114154 After 10 hrs then Drive Chain oil bath Refer to Page 14 OMC Type C every 25 hrs Once a season Secondary Drive grease fitting Two pumps of grease OMC Grease 114154 Once a season Primary Drive grease fitting 1 3 to 1 2 teaspoon OMC Grease 114154 normal use Do not over lubricate Twice a season extended use e e d Specified lubricants available from your dealer PREVENTIVE MAINTENANCE TIME MAINTENANCE After first 10 hrs then every Adjust Chain Tension 50 hrs or as required See Page 10 4 After first 10 hrs then every Adjust Track Tension 25 hrs or as required Check Track Alignment See Section 11 Twice a season see below
59. ck or piston scored Le 4 5 Excessive carbon on pistons and cylinder head 9 Compression relief valve improperly ad justed or faulty Exhaust ports or exhaust system carboned up 4 Charge coils Power Pack I faulty Idles well but acceleration poor dies at full throttle Fuel lines or passages obstructed b Fuel filter clogged Faulty fuel pump or pulse line Fuel cap vent clogged High speed nozzle or jet clogged Dirt or packing behind needles and seats Choke partly closed h High speed needle set too lean i Advance sensor faulty Advance and retard sensor leads interchanged on Power Pack I Engine runs at high speed only by using hand primer a Fuel lines or passages obstructed b Fuelline leaks or fuel filter obstructed c Fuel pump not supplying enough fuel d Leaf block base plate reversed Dirt or packing behind needles or seats Carburetor adjustments 95 Fuel vent clogged RUNNING HIGH AND LOW SPEED Engine overheats a Incorrect gas lubricant ratio or improperly mixed fuel b Engine not assembled correctly during repair binding Lean mixture carburetor adjustment d Cooling fan obstructed 2 Engine seizes stops suddenly 5 a No lubricant in gas fuel b Rod or main bearing seized Cylinder or piston scored or seized Engine knocks excessively a Incorrect gas lubricant ratio c
60. cks back and with timing light con nected will show yellow fin when cranking has a defective retard sensor coil or Power Pack If previous tests on the Power Pack were positive a resistance check of the sensor coil should be made A Remove the white black stripe lead from terminal 8 the black white stripe lead from terminal 7 and the white green stripe lead from terminal 6 Check for 27 to 29 ohms resistance between leads 6 and 7 See Figure 7 20 If retard coil resistance does not come within these tolerances it must be replaced B Retard coil or lead must not be shorted to ground On ohmmeter hi ohms scale check for a reading of infinity from either coil lead to ground If there is a leakage to ground check retard coil and leads and insulate area of leakage with tape TEST 9 CHARGE COIL RESISTANCE CHECK Remove the brown white stripe lead from Power Pack I terminal 1 Check for a total resistance of the two charge coils from lead to ground of 860 10 ohms See Figure 7 21 If resistance of the charge coils does not come within these tolerances they must be replaced TEST 10 IGNITION COIL CONTINUITY POWER AND INSULATION CHECKS To determine accurately the condition of the ignition coil an ignition analyzer should be used Without the use of test equipment coils may be replaced needlessly A wide variety of ignition analyzers are available from various manufacturers The use of the Graham Merc O Tronic or St
61. connect brakelamp wiring at quick disconnect e Remove brake bracket to chaincase screws REPAIR Disassemble brake assembly as required noting relative positions of components to assure correct reassembly see Figure 10 12 Inspect brake pucks If the free floating puck is one half of its 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 NOTE Keep all oil and grease from puck surfaces Braking action will be impaired by contaminated puck slipping on brake disc surface BRAKE CABLE AND CAM ASSEMBLY b e Reassemble brake assembly and assemble to bracket See Figure 10 12 Tighten the adjustment nut until brake pins are seated at bottom of actuator cam Install adjusting fitting and nut to brake bracket With cable installed in hand lever insert brake end of cable through adjusting fitting as far as possible and install return spring and Washer See Figure 10 14 Assemble clamp screw and sleeve to the brake cable and insert screw through hole in actuator arm Assemble nut to clamp screw Pull brake cable through clamp screw until the hand lever is fully extended and all cable and fit tings are seated Tighten nut until washers make contact with the cable then tighten nut an additional turn to clamp the cable Bend excess cable u
62. d specifications The dimensions are 7 3 4 long x 5 1 8 wide x 7 1 4 high to top of terminals The Prestolite brand battery which is included with this vehicle is recommended and is manufactured for snow vehicle use Anchored ele ments reduce the possibility of vibration damage This battery is mani fold vented It does not have vented cell caps and vented caps should not be used on this battery A vent tube from the battery manifold exits through the snowmobile chassis The dangerously explosive hydrogen gases generated when charging or jumping a battery are therefore vented a safe distance from the hazard of spark at the battery terminals Check vent tube periodically to make sure that it is not pinched clogged or ruptured The battery is shipped dry It is activated with dry charge electrolyte available locally Replacement battery is Prestolite Part No 2920 in Canada and 9955X in the USA REMOVAL AND INSTALLATION Filler caps must be tight and plastic tube outlet extended below bat tery for manifold system to function correctly See Figure 7 42 Prior to removing battery from compartment disconnect vent tube Pull tube straight down to remove it from the battery Reconnect vent tube when battery is replaced in vehicle Push tube straight up into battery until seated 7 17 Battery Electrolyte is a strong acid solution and should be handled with care If Electrolyte is spilled or splashed on any part of the body IMMED
63. distant within 1 32 inch See Figure 11 4 TRACK ALIGNMENT ADJUSTMENT E os Proper track alignment is essential to keep sprocket and track wear at a minimum Alignment can be seriously altered by improper adjustment of the track tension and rear axle location Proper track alignment is essential to keep sprocket and track wear at a minimum Alignment can be seriously altered by improper adjust ment of the track tension and rear axle location 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 5 If alignment cannot be obtained check for bent pivot arms loose bearings in pivot arms deformed slots in adjusting bracket or bent running board in area of adjusting bracket PIVOT ARM ADJUSTING SCREW BRACKET T A 2 2 1 2 1 32 Figure 11 3 ADJUSTING BRACKET TRACK TENSION EQUAL BOTH SIDES WITHIN 1 32 CLEARANCE SIDES 700 Figure 11 5 11 4 REMOVAL OF TRUCKS AND TRACK 1 Support snowmobile so that weight is removed from track 2 Release track tension See Page 11 3 3 Remove pivot axle bolts and truck axle bolts See Figure 11 6 Truck assemblies are now free of chassis IDLER AXLE 4 Remove bearing cup from front axle on side opposite the drive s
64. e Disconnect primer hose at intake manifold Disconnect inlet hose from fuel pump See Figure 9 5 FUEL RETURN HOSE UPPER MUFFLER M Sa Figure 9 5 9 Disconnect fuel return hose at carburetor See Figure 9 5 10 Disconnect compression release control from bracket See Figure 9 5 11 Remove heat shield 12 Remove two exhaust manifold to upper muffler screws Remove two screws securing upper muffler to chassis Remove upper muffler See Figure 9 5 13 Remove two screws securing exhaust manifold to lower muifler 14 ELECTRIC START ONLY Disconnect battery leads Remove lower engine cover mounting bracket Disconnect all leads from solenoid and rectifier See Figure 9 6 15 Remove all clamps and tie straps securing electrical wiring 16 Remove four nuts and washers attaching engine frame to chassis 17 Remove engine assembly from chassis ENGINE DISASSEMBLY a Before disassembly clean outside of engine to prevent dirt from getting On internal parts of engine b Remove carburetor intake manifold and leaf valve assembly For detailed instructions see Section 6 e Remove primary drive assembly See Section 10 ELECTRIC START ONLY Remove electric starter with bracket Remove manual starter assembly and outer fan housing Remove manual starter ratchet assembly flywheel and inner fan housing Remove stator sensor plate and rotor Remove Power Pack I cover then remove Power Pack I
65. e correctly pro portioned and thoroughly mixed It is the function of the carburetor to accomplish this Gasoline vapor will burn when mixed with air in a 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 simple metering device diaphragm and valve system allows a constant fuel supply to be maintained in the metering chamber at atmospheric pressure Needle valves permit a precise amount of fuel to flaw from the metering chamber to the car buretor throat The upstroke of the piston creates a suction which draws air through the leaf valves and the carburetor throat Ata particular point the throat is restricted by a venturi see Figure 3 4 The venturi has the effect of reducing air pressure in the air stream creating a partial vacuum which draws fuel from the discharge port As it is rushed along to the firing chamber the fuel is swirled about in the air stream and vaporized 3 3 INDUCED LOW PRESSURE FUEL FORCED UPWARDS BY ATMOSPHERIC PRESSURE 17136 3 4 HOLE FOR FUEL INTAKE PUMP PULSE MANIFOLD ACTION
66. e ee 9 8 2 REMOVAL AND 8 2 CLEANING INSPECTION AND REPAIR 8 3 REASSEMBLY cassa 8 8 STARTER ROPE REPLACEMENT 6 4 8 2 DESCRIPTION The manual starter converts straight hne motion to rotary motion necessary to crank the engine Pawls on the starter pulley engage the flywheel ratchet when the starter 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 Bison It is good practice to wear safety glasses while disassembling and reassembling manual starters because of the rewind spring n Remove three screws see Figure 8 1 attaching manual starter as sembly to fan housing Remove starter assembly from fanhousing b Pull starter rope out and untie knot in handle while holding rope c Ease rope back into starter until starter spring is fully unwound d Remove spindle screw and remove all components of starter pulley spindle assembly see Figure 8 1 e Jar the housing pulley side down on bench to dislodge spring washer and pulley from housing EARNER PAWL a PULLEY GUARD SPACER FRICTION RING SPACER 7 2 ll 7 UM
67. e ignition coil orange primary leads from terminals 2 3 of Power Pack I B Use neon tester 880 or M80 Set rotary switch on tester to position 1 Hook tester black lead to Power Pack I terminal 2 or 3 and tester blue lead to engine ground See Figure 7 17 C Depress load button A and crank engine with electric starter or manual starter with ignition switch in RUN position and observe light See Figure 7 16 1 If tester light is bright and steady check ignition coils test 10 2 If tester light is weak or erratic check ignition switch test 2 charge coil output test 3 or retard sensor coil input test 74 D Reconnect ignition coil primary leads to terminals 2 and 3 on Power Pack 1 REPLACE GROUND WIRE ADVANCE CHARGE AND NUT AFTER SENSOR colL SE d REMOVING COVER LIGHT TO 1 POWER 1 AQ DEPRESS n EA BUTTON A ADVANCE i COMMON RETARD SENSOR COIL NEEDLE POINT SPARK CHECKER 1 2 GAP Figure 7 17 7 9 TEST 6 IGNITION SWITCH CONTINUITY GROUND CHECK Pull high tension leads off spark plugs B Connect spark gap checker with 1 2 gap See Figure 7 18 Crank engine with electric starter or manual starter with ignition switch in RUN position Remove plu9s for easier cranking D If weak erratic or no spark disconnect ignition switch orange black lead on Power Pack terminal Repeat test cranking engine with rope
68. e plate on instrument 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 ad justment or possible binding 1 Assemble the carburetor to the intake manifold Install fuel lines and air filter to carburetor Install new fuel line tie straps eo Assemble throttle cable to carburetor in reverse order of dis assembly Adjust throttle cable so that carburetor butterfly valve is full open when thumb lever touches handle grip Figure 6 6 When the lever on the carburetor is returned to the idle posi tion there must 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 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 Do not blow dry with air pressure as damage to leaves may result c Inspect the leaf valve assembly and disassemble if necessary see Figure 6 7 Special caution is necessary in disassembling the leaf valve assembly DO NOT damage or interchange the leaves d The leaves must be flat to maintain a seal with the leaf valve body DO NOT under any circumst
69. e snowmobile 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 unnecessary 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 specif
70. eplaced 5 Inspect wheels for excessive wear or peeling of coating If they must be replaced first loosen Allen set screws to remove wheels from axle TRUCK DISASSEMBLY See Figures 11 7 and 11 8 1 Remove lock nuts from front and rear truck axles and pivot axle 2 Remove pivot arms spacers bushings and springs from pivot axle 3 Wheels and spacers will now slide off front and rear truck axles CLEANING INSPECTION AND REPAIR Track 1 A torn track cannot be vulcanized It must be replaced if torn be yond use 2 Small cracks will not hamper the operation of the snowmobile 3 Liquid neoprene can be applied to cracks or frays to help restore its original appearance Trucks And Axles 1 Axles check for straightness by rolling on a flat surface If drive axles are bent they must be replaced Truck axles may be straightened 2 Splines inspect for excessive wear 4 Check to see that oil plug in front axle is in place and does not leak 4 Check condition of seals on front axle and replace if seal lip is not tight on axle us Check nylon truck bushings for cracks or excessive wear Replace if damaged e A gt PIVOT HANGERS ARMS TRUCK AXLE REAR TRUCK PIVOT FRONT AXLE AXLE TRUCK AXLE TRUCK ASSEMBLY 17122 Figure 11 8 11 6 SPRING RETAINING TAB Figure 11 9 REASSEMBLY 1 b Assemble wheels and spacers to their original positions on
71. etween 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 IGNITION The magneto capacitor discharge C D ignition system generates a high voltage electric current which jumps the spark plug gap within the and thus ignites the compressed fuel air mixture in the cylin der See Figure 3 6 This system is made up of the following major components 1 Flywheel assembly 4 Sensor plate assembly 2 Sensor rotor 5 Power Pack I assembly 3 Stator and charge coil assembly 6 Ignition coils The following sequence of events will illustrate howthis system works The flywheel rotates around the stator and charge coil assembly See Figure 3 7 The magnets in the flywheel and the 2 charge coils wenerate a voltage This voltage AC flows into the Power Pack I Here it is changed to DC and stored in a capacitor At the same time the sensor rotor rotates by the sensor coils and a smaller AC voltage is generated This smaller voltage flows into the Power Pack I and causes an electronic switch in the Power Pack I to turn on aliowing the voltage stored in the capacitor to discharge into the primary of the ignition coils One thing to note in this system is that there
72. evens ignition analyzers and their adapter for C D ignition are particularly recommended See Figures 7 7 7 8 and 7 9 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 though replacing a single part seems to have corrected the trouble The following values are provided for checking the ignition coil Graham Tester Model 51 Maximum Secondary 1900 190 Coil Index 60 Minimum Coil Test 9 Gap Index 90 Merc O Tronic Operating Amperage 1 4 Secondary Continuity 22 to 26 index number Stevens Tester Model Switch B Index Reading 20 A SAFETY WARNING Perform all tests on a 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 NOTE Zero meter before performing the continuity test A CONTINUITY TEST using MERC O TRONIC TESTER Remove ignition coils Connect meter leads to coil primary and secondary leads and turn meter selector switch to Coil Continuity see Figure 7 22 Index reading should be between 22 and 26 B Connect meter leads to adapter adapter red lead to coi
73. gapped dirty or broken Loose or broken ignition coil wires spark plug terminal loose Weak coil Cylinder gasket or leaf plate gasket damaged i Leaking crankcase gaskets or crankshaft seals Arcing around ignition coils or arcing nition switch Loose connections or intermittent grounding of leads in the ignition coil Power Pack I charge coils sensor coils and ignition switch RUNNING HIGH SPEED ONLY 1 High speed miss a Water in fuel b Carburetor inlet needle sticking c Spark plugs improperly gapped or dirty cracked insulator Ignition coil weak output Engine improperly timed f Exhaust ports or exhaust system carboned g Combustion chambers carboned or fouled h Arcing around ignition coils or arcing in ig mtion switch 1 Loose connections or intermittent grounding of leads in the ignition coil Power Pack I charge coils sensor coils andignition switch 2 Poor acceleration top rpm is low a Incorrect gas lubricant ratio b Old fuel Fuel hoses plugged or kinked Fuel filter restricted fuel pump or carburetor Fuel pump or pulse line faulty f Incorrect carburetor adjustments g Inlet needle and seat worn or sticky h Timing out of adjustment i Spark plugs dirty or improperly gapped j Loose broken or badly insulated high ten sion leads k Ignition coil weak output L Leaf valves not properly seated or broken m Piston rings stu
74. gine 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 op erate on a mixture which is too lean until the gasoline and lubricant have been agitated by then damage would have occurred and the engine would have to run on an excessively rich mixture The correct fuel mixture ratio is 50 1 or 1 pint of lubricant to 6 U S gallons 4 8 Imperial gallons of gasoline See inside front cover 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 a good grade of regular leaded 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 50 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 90 to 1 lubricant is prediluted to provide excellent mixability with gasoline at low temperatures The addition of this dilutant does not in any way affect the lubrication qualities of the lubricant Whenever it is necessary to mix fuel and lubricant at temperature below 32 F 0 C the lubri
75. gure 9 10 Place part to be surfaced on emery cloth and move slowly back and forth several times in a figure 8 motion exerting evenly distributed light pres sure Lift part from surface plate to observe results If surface is actually warped or spring high spots making 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 toa dull luster Finish surfacing with No 180 emery cloth PISTONS a 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 11 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 Figure 9 11 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 12 Check pistons for roundness taper excessive skirt wear and scoring Piston skirts must be perfectly round and unscratched to prevent entry of exhaust gases into crankcase chamber Check piston size taper and roundness using a micrometer see Figure 9 13 Check clearance between piston and cylinder before rein stalling pisto
76. hat the armature windings are grounded and armature must be re placed Check armature for open windings by using an ohmmeter Meas 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 7 21 VOLTMETER AMMETER TACHOMETER Figure 7 49 VOLTMETER GROUND MOTOR IN AREA THAT AMMETER CLAMP THIS LEAD FIRST TO PREVENT ARCING ON THREADS Figure 1 50 Figure 7 51 1 22 Figure 7 52 CORRECT Figure 7 53 STARTER BELT TENSION ADJUSTMENT M STARTER B BELT 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 53 t After commutator has been undercut sand lightly with No 00 sand paper to remove burrs left during the undercutting process After sanding clean commutator thoroughly removing all traces of metal chips or sanding grit and recheck armature on growler g Inspect armature insulatio
77. he 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 the casting Inspect the shaft and bushings 1 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 Check with straight edge See Figure 6 5 2 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 flat end punch The correctly installed welch plug is flat Stake plug at outer edge in three places 3 Assemble the gaskets diaphragms and castings in the correct order See Figure 6 6 4 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 9 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 6 Insert choke cable assembly through projection on carburetor and insert cable through choke lever swivel pin With choke knob flush against fac
78. heel pulleys c Turn movable half of pulley counterclockwise to drive position See Figure 7 54 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 headlights 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 connections throughout the circuit before proceeding with electrical testing A visual inspection may be all that is required to locate the trouble nore Disconnect battery leads before tightening or changing any con nections to avoid the possibility of shorting out the electrical system 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 caused 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 c Connections Although connections are easily m
79. ications 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 A 4H Hood Lock Levers 7 Throttle Neutral Control 8 Engine Cover Hi Lo Beam Head 9 Choke Lever light Switch 10 Compression Release Ignition Lights Start 11 Primer Switch 12 Manual Starter Hand Brake 13 Engine Cover Latch Parking Lock 14 Safety Stop Switch Figure 1 2 SECTION 2 SPECIFICATIONS TABLE OF CONTENTS SPECIFICATIONS cece eee matinee mee 2 2 TORQUE SPECIFICATIONS 2 4 Snowmobile Special Service Tools PART NO DESCRIPTION 378103 Flywheel Puller 404032 Wrench Primary Drive Pliers 426030 Ring Compresser 383966 Spring Winder Heli Coil Installers and Inserts 404068 Riveting Tool 375632 Spark Plug Wrench 114146 Splined Wrench 113971 Flywheel Holding Tool 114147 Drive Alignment Gauge 261906 Disassembly Tool Primary Drive 261132 Retaining Ring Bearing Puller 261131 Half Steel Bearing Puller 261131 Extractor Crankshaft Bearing 317829 Driver 317830 Cone Refer to the Tool Catalogue SPECIFICATIONS PROHIBITED Snow Vehicles are not manufactured for highway use and the manufacturer does not represent that they are equipped with all the devices legally required for such use xv vip nudus piv 4 4 989 4 inches W
80. idth mani asta Wir oe ory a iy Wore T Ala 32 6 inches Heighl 9 6 ju le s 39 inches with windshield 34 5 inches without windshield Engine 395 4 3 5 44 8 8054 4 2 cycle opposed twin Rating High Performance 5 gt gt at 6000 RPM 6 Qaa Une A E TA Electric and Manual Rewind Variable Speed Drive Centrifugal operated sheave engages V belt kh A the Wa ee Gi 3 33 to 1 Final drive RE 5j 912 ASA 35 double chain TANO 15 datandet nv ve ele OP reat me 16 30 optional sprocket 2 18 80 415 vh EC Tuned for maximum performance Wie a Disc type hand operated CONLE lt 939 64 575 vot ES Thumb operated Ee designed flexible track fully adjustable avis a a aca RR i ye 15 4 inches Skis Formed steel equipped with shock absorbing leaf springs and replaceable wear runners Seat 4 sa coated cover molded urethane foam cushion HO DU 6 Molded fiberglass Headlamps Sealed beam GE 4445 T
81. ion spring Inspect for damaged threads see Figure 6 7 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 c Remove the hinge pin retaining screw 25 the hinge pin 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 carefully Do not stretch this spring or change its compression characteristics If in doubt about its condition replace it 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
82. l ground lead and adapter black lead to coil primary See Figure 7 23 Connect coil high tension lead to meter output lead Turn meter selector to Coil Power Test and apply power to coil Secondary voltage should produce a steady spark at meter spark at 1 4 amps black figures on number 1 scale Check insulation by probing the coil and entire secondary lead with the grounded test probe See Figure 7 24 Arcing will be apparent wherever the insulation has broken down due to moisture or carbon trails TEST 11 IGNITION TIMING CHECK RETARD TIMING CHECK Connect test light to battery Remove spark plugs to release com pression for easier manual turning of engine Clamp the test light elec tronic pickup on a spark plug wire Arrow on pick up must point toward plug Connect spark checker to high tension leads and ground to engine Turn ignition switch to RUN position It will be required that one person pull the starter rope vigorously and second person aim the test light at the timing slot and check the retard red fin on the flywheel which should be visible at cranking speed in the timing slot See Figures 7 26 and 7 27 7 11 SECONDARY 27104 LEAD Figure 7 22 METER OUTPUT ADAPTER COIL PRIMARY 27105 COIL SECONDARY Figure 7 23 METER LEADS METER ADAPTER Se ADAPTER LEADS COIL SECONDARY Figure 7 24 7 12 ELECTRONIC PICK UP 4TH FIN COUNTER FLYWHEEL KEYWAY
83. l on 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 The 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 45 Starter belt tension must be set with sufficient slack to prevent the engine from driving the starter motor See BELT TEN SION MAINTENANCE The only starter motor maintenance required is periodic cleaning of the outside of the starter motor and drive and a 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 If the starter motor does not crank the engine or if it cranks 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 starte
84. l ventilated area REMOVAL FROM STORAGE b C d 1 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 control 2 Function of brake 3 Engine performance Thoroughly clean any surfaces that need refinishing and touch up
85. late and base assembly on crankcase Install intake manifold on crankcase using a new intake manifold gasket Be certain that elongated hole in base plate aligns with passage in intake mani fold See Figure 6 7 Obstruction of this passage will prevent fuel pump operation via the pulse line Fasten with screws and lockwashers b Attach primer check valve hose to check valve on manifold c Attach assembled carburetor to intake manifold with screws nuts and lockwashers using a new carburetor gasket FUEL PUMP REMOVAL a Disconnect three hoses from fuel pump and filter assembly LEAF PLATE AND BASE ASSEM E b Remove two screws attaching pump and filter assembly to mount ing plate see Figure 6 8 and remove pump and filter assembly NOTE Filter assembly may be removed for cleaning and inspec tion without removing pump assembly by removing filter cap screw FUEL PUMP see Figure 6 9 BODY GARRET A WARNING Do not allow fuel to drip on hot engine or exhaust manifold because of potential fire hazard CLEANING INSPECTION AND REPAIR a The fuel pump components not serviced separately If a mal function occurs replace the complete pump MOUNTING HOLES b Check for clogged filter element The fuel filter element on an Figure 6 8 engine that has been in storage may be clogged without appearing to be During storage volatile agents as well as anti gum and anti varnish agents evaporate from the gasoline that rem
86. mber a lean fuel mixture or improperly installed spark plugs can cause overheating e The condition of spark plugs may provide an indication of other con ditions requiring attention Inspect each plug and gasket as itis 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 re 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 flat 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 If 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
87. n see Figure 9 14 Check tolerances on spec sheet 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 15 Press ring down in bore slightly with bottom of piston to square it up Discard and replace with different ring if gap is too large or too small see Section 2 Specifications Check each ring in its respective ring groove for tightness or bind ing by rolling the ring around the piston groove see Figure 9 16 Check for groove side clearance with feeler gage see Figure 9 17 see Section 2 Specifications BEARINGS 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 a Clean bearings while they are still on crankshaft by emersing them 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 into the bearings Agitate bearings frequenely until all oil grease and sludge have been loosened and can be flushed out Bearings with especially heavy carbon deposits or hardened grease should be soaked in a separate container of solvent Use a spray gun with air filter and a cleaning solvent to flush each bearing until all dirt and residue have been
88. n Section 3 TRANSMISSION BELT INSPECTION amp REPLACEMENT A belt measuring less than 1 1 16 across the width or outer surface must be replaced with a new one Worn belt may be retained and used asaspare A spare belt should be carried at all times NOTE DO NOT RUN ENGINE WITHOUT BELT BELT REMOVAL PROCEDURE FIGURE 10 1 BELT i a SECONDARY DRIVE E 2 ES pA PULL SLIDING SHEAVE WHILE TWISTING TO LEFT 27 A SAFETY WARNING KEEP FINGERS FROM BETWEEN HALVES OF SECONDARY WHEN PERFORMING STEP 4 e io DAR 8 1 1 RIDE BELT OFF SHEAVE AS SHEAVE IS TWISTED TO RIGHT AND CLOSED 1 AN S WORK BELT OVER TOP OF SHEAVE v jJ Y MOVE BELT BETWEEN ENGINE AND SECONDARY SHEAVE WORK BELT OUT FROM WORK BELT BETWEEN END CAP UNDER BOTTOM OF SHEAVE gt AND EXHAUST MANIFOLD m Figure 10 1 BELT REPLACEMENT PROCEDURE Replace in reverse order of removal PRIMARY DRIVE REMOVAL OF PRIMARY SHEAVE ASSEMBLY Ei sore Primary drive is dynamically balanced Before disassembly mark relative position of end cap and pulley assembly 1 sliding sheave 2 and fixed sheave 3 for proper alignment on reassembly See Figure 10 4 After removing the transmission belt as described above the primary sheave assembly can be removed using the following procedure 1 Remove star
89. n complete wrist pin installation d Replace retaining rings using Driver 317829 and Cone 317830 Making certain they seat securely in the groove provided Check piston with micrometer to determine whether piston has been distorted during assembly Maximum permissible distortion is 003 below wrist pin boss only PISTON RINGS a Install the piston rings on each piston Spread each ring with a ring expander just enough to slip it over the head of the piston and into place see Figure 9 19 Be sure that the rings fit freely in the piston ring grooves b Be sure that piston rings are correctly positioned in piston ring grooves Be sure dowel pins on piston are centered between ring paps 9 9 BEARINGS CRANKPINS Figure 9 19 Figure 9 20 Figure 9 21 CRANKSHAFT NOTE Shims must be installed on crankshaft between the bearing and thrust face of crankshaft on flywheel end a Install crankshaft shims and journal bearings on crankshaft using an arbor press Be sure to support properly to prevent distor tion Shims must be installed on primary drive side not magneto side of crankshaft between the bearing and the thrust face of crankshaft Crankshaft end play should not exceed 019 after installation Total dimension across bearings should be 4 933 001 See Figure 9 20 b Remove connecting rod caps from connecting rods Apply a coat of OMC Needle Bearing Grease Part No 378642 to connecting rod bearing area
90. n 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 a Inspect the brushes replace if worn to one thirdtheir original 3 8 length or if damaged or cracked Replace brush springs if weak b 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 BELT TENSION a Correct starter motor drive belt tension is extremely important A 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 b Install starter belt between starter and flyw
91. n open flame at each end for about one halfinch Rope ends must be stiff to hold in pulley 1 Insert rope through pulley and starter housing See Figure 8 2 Seat rope knot firmly in pulley Tie slip knot in starter rope and allow pulley to rewind k Install pawls retainers and screws if they have been removed l Assemble starter rope to handle and secure with knot m Pull on starter rope to make certain that pawls work properly When starter rope is pulled pawls should pivot to engage flywheel ratchet On releasing rope pawls should retract to starting posi tions n Attach manual starter assembly to fan housing with three screws Do not apply grease to starter spring Most lubricants solidify in cold weather and will make the starter inoperative DEGCBHIPTION o idic isu pr ra 9 2 ENGINE 9 2 DISASSEMBLY 9 3 CLEANING INSPECTION AND 9 6 CYLINDEHS s n Pye 9 6 GASKETS AND GASKET SURFACES 9 6 PRETUNS 9 6 BEARINGS ASSEMBLY OF ENGINE 4 9 8 PISTONS WRIST PINS AND CONNECTING RODS 2 6 2 5 5 9 8 PISTON RINGS 1 P Ww P 9 8 CRANKSHAFT 9 9 CEXLINDEHB 9 10 INSTALLATION OF ENGINE
92. n shaft compress spring and lock in place with strap Service Tool No 261906 Lubricate splines with OMC Part No 114154 BEFORE REASSEMBLY 4 Assemble end cap on shaft making sure end cap splines engage shaft splines Apply Loctite to end cap bolt Figure 10 9 5 Before placing bolt in shaft check to see that neutral lockout balls have not fallen from their holes in shaft 6 Tighten end cap bolt to correct torque See Page 2 3 7 Check the neutral lockout plunger to see that it snaps in and out properly 8 Assemble lock plate to end cap Locks on lock plate may engage bolt by turning lock plate over Otherwise a slight loosening or tightening of bolt may be necessary in order to align bolt with lock 9 Clean inside of sheave halves of any grease that may have accumu lated on them 10 Reinstall transmission belt as described on page 10 2 DRIVE CHAIN REMOVAL Extreme caution should be taken when removing chain case cover to overcome distortion of cover and damaging chain case 1 Remove chain case cover Oil will drain from chain case when cover is removed 2 Loosen chain see Adjustment 3 Remove cotter pin and nut from upper drive sprocket See Figure 10 10 4 Remove sprocket and chain from upper shaft 5 Chain can now be removed from lower sprocket INSTALLATION 1 Assemble in reverse order of disassembly 2 Adjust chain per Adjustment 3 Add chain lubricant per Lubrication
93. n 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 cycle 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 A piston stroke is piston travel in one direc tion only up is one stroke down is another In a four cycle engine 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 a two cycle engine the ignition of the fuel air mixture occurs as the piston reaches the top of each stroke The 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 The 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 carburetion The 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 poin
94. nce to specified torque See Figure 9 22 b Install compression relief valve to forward cylinder using Dupage high temperature thread compound applied to the threads Torque to specifications c Attach cylinder and crankcase group to engine frame d Install compression relief cable assembly and adjust See Page 9 5 e Install inner fan housing with magneto and alternator flywheel and outer fan housing ELECTRIC START ONLY install starter motor belt See Section 7 for belt adjusting procedure f Install manual starter see Section 8 g Install leaf valve assembly intake manifold and carburetor For detailed instructions see Section 6 Apply OMC Gasket Sealing Compound 317201 on intake manifold gaskets h ELECTRIC START ONLY Install electric starter Figure 9 22 Figure 9 23 1 Manifold Gaskets 8 Muffler Bracket Serew 2 Front Exhaust Manifold 7 Upper Muffler 3 Rear Exhaust Manifold 8 Manifold to Muffler Screw 2 4 Muffler Gaskets 9 Lower Muffler Mounting 5 Manifold to Muffler Screw 2 screw 3 INSTALLATION OF ENGINE ASSEMBLY TO CHASSIS 1 a b c 8 10 11 12 13 Assemble exhaust manifolds to cylinder barrels if they were re moved Use the following procedure Place new exhaust manifold gaskets over cylinder studs and then assemble front and rear exhaust manifolds See Figure 9 24 The gasket surfaces on cylinders and manifolds must be clean and smooth see
95. nector or rrounded switch wire a Binding in engine t Faulty sensor charge coils Power Pack I connecting wiring Engine won t turn over Cylinder wall corrosion seized piston or bearing b Engine improperly assembled after repair Cranks over extremely easily Spark plug s loose b Cylinder or pistons scored Rings worn or carboned d Faulty crankcase wasket or crankseal s fu Broken or damaged leaf valves Won t start but kicks back and backfires a Leaf valves broken or not seating b Sensor leads on Power Pack I terminals 6 amp 8 reversed c Timing out of adjustment check sensor hub key d Advance sensor faulty or out of adjustment e Power Pack I faulty No spark one cylinder a Faulty ignition coil wire or connections b Faulty Power Pack I 4 4 1 No spark both cylinders a Faulty charge coil b Faulty sensor coil Faulty Power Pack I d Grounded ignition switch and or wire e Flywheel not magnetized Faulty ignition coils or leads Weak spark both cylinders Ignition switch or connection leakage b Weak charge coils Weak Power Pack I output d Weak ignition coils Engine can be started by using primer but dies out when primer is not used a Fuel pump inoperative b Fuel line or check valve between primer pick up and carburetor clogged Fuel filter screen in fuel pump or carburetor inlet screen clogged
96. onditions 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 37 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 9 4 NN AN ee Figure 7 38 Figure 7 39 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 38 A dark black or sootish coloration or wet appearance ordinarily indicates the heat range as being too cold see Figure 7 39 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 ignition components A definite white coloration may indicate the presence of moisture in the combustion chamber Similar deposits are caused by pre ignition d Oil fouling deposits wet sludgy deposits and is a result of mis firing or of excessive oil in the fuel mixture see Figure 7 40 Burned or overheated spark plugs may be identified by white burned or blistered insulator nose and badly eroded electrodes Excessive deposits in the combustion cha
97. ore being returned to service DO NOT recharge the battery by the fast charge method This method does not restore the full charge and also shortens the life of the battery DISCONNECT one of the battery leads before attaching battery charger to battery SLOW CHARGING Battery is kept charged by alternator coils located beneath flywheel It may be necessary to use a separate 12 volt battery charger sionally to keep battery fully charged during long storage periods or in extreme cold weather if engine is started repeatedly Battery should be removed from compartment for charging and initial filling Prior to removing battery from compartment disconnect vent tube Pull tube straight down to remove itfrom the battery Reconnect vent tube when battery is replaced in vehicle Push tube straight up into battery until it is seated Adjust electrolyte to proper level by adding water then charge battery at a maximum rate of 4 amperes until fully charged Leave caps on battery while charging Battery is fully charged when hydrometer scale shows a corrected reading of 1 260 and does not change after three hourly readings Cells will gas freely when fully charged PRESTOLITE BATTERY WARRANTY Warranty on Prestolite batteries used in this snowmobile is covered directly by Prestolite through their authorized battery service stations for a period of 15 months in the United States and 9 months in Canada Should a battery fail d
98. ormation on the piston skirt Cylinder bores normally wear with operation of the engine The de wree of wear will vary with length of operation efficiency of lubrication and general 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 cylinder wall increases friction caus ing high operating temperature sluggish performance and abnormal wear or scoring Insufficient pressure allows blow by which reduces power and causes overheating and carbon formation on piston skirt Since the ring tends to flex as it follows the cylinder contour during engine operation clearance or 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 spark plugs A cracked spark plug insulator will cause similar trouble Although compression 1 pri marily dependent on the piston rings and cylinder these other sources of leakage should be investigated when compression loss is noted
99. p approximately 90 Back off adjusting nut 1 4 to 1 2 turn Adjust brake BRAKE ADJUSTMENT Brake adjustments can be made by turning the adjustment nut clock wise to tighten brake a b Turn the nut until there is a slight drag on the brake then back the nut off 1 4 to 1 2 turn Work brake lever three times to insure that there is no cable slip at clamp screw Turn adjusting fitting located on brake bracket out until hand lever will just allow the parking brake lock to be engaged When park ing brake lock is released the hand lever must return to free position Actuate hand lever and set parking brake lock to insure proper ad justment has been obtained Tighten nut on cable adjusting fitting on the brake bracket When brake is off pucks should not drag on brake sheave 10 7 SECONDARY DRIVE DISASSEMBLY 1 Remove gas tank 2 Remove belt guard see Page 10 2 3 Remove transmission belt see Page 10 2 4 Remove brake assembly not necessary to disconnect cable See Page 10 6 5 Remove chain case cover 6 Caution should be taken not to warp cover 6 Loosen chain 7 Remove cotter pin 7 nut 8 and upper sprocket 9 8 Remove outer bearing cone washer 10 outer bearing cone 11 and bearing spacer 12 SECONDARY i DRIVE 9 Remove eccentric adjusting screw 13 zT 10 Remove chain case support stud 2 11 Loosen the four chain case mounting screws 22 12
100. page 2 3 for torque specifications Place lower muffler in well Install engine and frame to chassis Install primary sheave assembly See Section 10 Install transmission belt See Section 10 Connect throttle cable Adjust throttle lever so that throttle shutter is full open when throttle lever is in contact with handle grips Reconnect electrical connectors Install upper muffler and heat shield Adjust upper muffler so there is clearance between exhaust pipe and outlet in chassis and so that exhaust pipe does not extend more than 3 32 through chassis out let Reconnect compression relief cable See Section 5 for compression relief cable adjustment Install spark plugs and connect leads Reconnect fuel lines and throttle cable See Section 6 ELECTRIC START ONLY Reconnect all leads to solenoid and rectifier Replace lower engine cover mounting bracket Reconnect battery leads Replace all clamps and install new tie straps securing electrical Wiring See FUEL LINE TIE STRAPS in Section 7 Install hood in reverse order of removal BREAK IN PROCEDURE a Be certain that when an engine is returned to service following an overhaul the owner is advised to follow break in procedures as described in the Owner s Manual exactly This will allow the in ternal moving parts to seat themselves thus greatly prolonging engine life b For the first tankful of fuel the vehicle must be operated at re duced speeds Allo
101. pect ball joints Replace if worn or damaged f Check for 1 16 end play in steering column Correct by moving steering column support REASSEMBLY a Reassemble skis to leaf springs b Replace ski column and assemble to steering arm Lubricate ski columns See Page 12 4 NOTE DO NOT interchange right and left ski columns and steering arms c Attach steering arms to ski columns noting original position Tighten to torque value shown in Section 2 Adjust ski alignment as described below SKI ALIGNMENT a Ski alignment is necessary when skis are not parallel with each other and the vehicle body with the handle bar in the normal straight driving position b If alignment is necessary loosen the outer jam nuts see Figure 11 2 A sarery WARNING Do not attempt to loosen outer jam nuts without first holding the ball joint as this could put undue stress on the ball joint Next remove lock nut from ball joint Turn ball joint clockwise to toe skis out or counterclockwise to toe skis Tighten jam nuts when skis are parallel Replace ball joint lock nut ALL MEASUREMENTS CENTER TO CENTER 17 c In order to verify your ski alignment use the measurements shown Figure 11 2 in Figure 11 2 d The ski columns are not identified right and left One flanged side is shorter This shorter side must be kept to the inside of the snowmobile Do not interchange or assemble in reverse e There should be approximately the s
102. procket Remove 3 nuts and lockwashers 9 Remove chain case cover 6 Remove cotter pin bottom sprocket and washer See Figure 11 7 PIVOT AXLES 7 Remove screw from bearing cup 8 Slide axle to right and drop left end of axle out bottom of chassis Figure 11 6 9 Front axle with bearings and seals is now free of chassis 10 Remove four track tension lock nuts See Figure 11 4 11 Rear axle can now be removed 12 Remove idler assembly Remove nut and washer from each end of axle as in Step 3 See Figure 11 6 13 Trucks axles and track are now free of the chassis FRONT AXLE DISASSEMBLY 1 Turn bearings by hand If they do not turn freely if there is ex cessive play or if they are rough they must be replaced Remove bearings with bearing puller or arbor press Take care not to Figure 11 7 damage seal which will come off with bearing 2 Inspect drive sprockets Check for excessive wear or peeling of coating If they must be replaced first drive out roll pins If heat is necessary to remove or reassemble front sprockets or rear axle wheels or sprockets use heat lamp or hot air gun for heating DO NOT use open flame 3 Press drive sprockets off front axle after marking reassembly position REAR AXLE DISASSEMBLY 1 Remove retaining ring and bearing retainer 2 Push pivot arm towards wheel 3 Check bearings as on front axle 4 Remove bearings only if they must be replaced or if wheels must be r
103. ption of the trouble b Preliminary inspection Use of Trouble Check Chart to analyze engine performance An accurate description of the trouble is essential for trouble shooting owner s comments may provide valuable information which will Serve as a clue to the cause of the problem A preliminary inspection should include the follow ing checks a Correct spark plugs b Throttle linkage properly adjusted c Tank filled with fresh clean fuel of the proper mixture d Spark at each spark plug e Carburetor adjusted correctly f Compression Turn flywheel by hand or with recoil starter If compression is present it can 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 b Incorrect gas lubricant ratio Old fuel or water or dirt in fuel system d Fuelline improperly connected e Fuelline kinked or severely pinched f Engine not primed Clogged fuel line or fuel filter h Clogged check valve i Carburetor adjustments too lean j Low speed needle bent or bowed k Engine flooded l Leaf valves not functioning properly m Faulty gaskets Spark plugs fouled improperly gapped dirty or broken Loose or broken wire or frayed insulation in ignition system wiring p Sheared sensor hub key 4 Faulty coils r Key switch con
104. r motor tests Starter circuit testing is a quick means of pin pointing causes of hard starting which may result from a faulty electri cal component in the starter circuit and can be performed without re moving 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 46 7 19 SOLENOID Figure 7 44 FIXED HALF OF PULLEY MOVABLE HALF OF PULLEY STARTOR BELT i TENSION ADJUSTMENT Figure 1 45 TEST BATTERY ns Figure 7 46 TEST VOLTMETER Figure 7 47 E 25 3 a 25 VOLTS STARTER SOLENOID 25 Figure 7 48 b Turn ignition switch to START and observe amperage reading with engine cranking Current should be between 75 amperes minimum and 140 amperes maximum after initial surge 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
105. removed Blow solvent out of bearings using dry filtered air Do not spin bearings by force of air Since dry bearings rust rapidly lubricate them immediately in light clean oil Rotate them a few times to spread the oil film and place them in a clean covered container for inspection later 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 tight a press fit 3 Worn galled or abraided surtaces These be caused by 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 BREAK THIS EDGE Figure 9 12 9 15 9 8 Figure 9 16 EXTRACTOR j HALF SHELLS EXTRACTOR PART 261129 HALF SHELLS 7 PART NO 261131 RETAINING RING a PART NO 261132 Figure 9 18 e If bearings must be replaced remove the old bearings using the following procedure Use special bearing removal tool shown in Figure 9 18 Position lips of half shells behind bearing and over extractor Slide retaining rings over half shells Turn extractor center screw to remove bearing This tool is a must if main bearing replacement is required Do not lose shims between bearing and
106. spot hesitation to accelerate is noted readjustment of low speed needle is necessary Turn low speed needle counterclockwise 1 8 turn at a time Reset idle adjust ment screw to attain 1300 1600 rpm each time low speed needle is adjusted 6 Accelerate engine then release throttle Engine should return to idle speed If engine does not idle immediately adjustment of the low speed needle may be necessary Turn low speed needle clockwise to reduce amount of fuel to the engine Reset idle ad justment screw to attain 1300 1600 rpm each time low speed needle is adjusted C nore Operating above recommended idle rpm can result in neutral control not operating If it is necessary to idle at above recom mended rpm check neutral control to insure it can be operated See page 3 6 SPARK PLUGS Using the correct spark plug is most important for efficient operation The recommended spark plug for your engine is Champion UJ2J 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 7 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 plug securely Recommended torque 20 to 25 ft lbs See page 7 14 for additional information on spark plugs 6 3 a Remove the idle speed mixture screw 14 washer and tens
107. t 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 power 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 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 to expand against the walls of the cylinder The 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 Escape of compression past the piston rings is referred to as blow by and is indicated by dis coloration or carbon f
108. t blocking diode test on yellow and blue lead Meter should read in both directions SAFETY STOP SWITCH TEST Pull connector apart and connect continuity meter across two stop switch leads a Depress button full continuity Figure 7 56 b Depress button run position no continuity DIMMER SWITCH TEST Disconnect head lamp connectors b Ignition switch OFF Connect continuity meter one meter lead to engine ground other meter lead to dark blue wire terminal at headlamp connector Depress button full continuity Depress button second time no continuity Repeat for each headlamp BRAKELAMP SWITCH TEST a Pull connectors apart near brake switch b Connect continuity meter to each of the terminals Pull up on switch plunger full continuity d Release plunger no continuity If brake is not properly adjusted brake switch will not function properly HEADLAMP ADJUSTMENT Headlamp is adjustable for elevation of beam and right or left throw of beam For elevation turn top screws in or out equally With high beam on adjust elevation of beam so that center of high intensity zone is 2 inches below center of lamp at a distance of 25 ft from headlamp For right or left throw of beam adjust outer screws until proper aim is obtained HIGH INTENSITY HEIGHT OF HEADLAMPS Figure 7 57 7 25 SECTION MANUAL STARTER TABLE OF CONTENTS DESCRIPTION 844699864 win
109. tall chain case support stud 14 Tighten chain case mounting screws 15 Reinstall bearing spacer 16 Assemble bearing cone to shaft 17 Replace upper sprockets nut and cotter key 18 Torque nut to 25 ft lbs Continue torquing until cotter key can be inserted 19 Assemble brake assembly on sheave and secure with mounting bolts 20 Reinstall brake assembly to chain case mounting boss 21 Clean inner surfaces of sheave halves of grease 22 23 24 25 26 21 28 29 30 31 Reinstall transmission belt Grease assembly thru fitting on eccentric adjustment Two pumps from a grease gun is sufficient grease Part No 114154 is recommended Check for proper position of secondary drive assembly Distance from center of primary drive shaft to center of secondary drive top sprocket must be 11 9 32 1 16 See Figure 10 17 Replace drive chain and adjust See Page 10 5 Chain case seal groove should be cleaned NOTE A new chain case cover seal must be used Apply 3M EC847 cement to seal Drive chain lubrication refer to Section 12 Replace belt guard Replace gas tank Primary and secondary alignment should be 2 1 16 plus or minus 1 16 measured from flanged edge of fixed primary sheave to flanged edge of fixed secondary sheave Figure 10 17 PRIMARY DRIVE 10 9 17122 CJ SECTION 11 STEERING TRACK AND SUSPENSION TABLE OF CONTENTS DESCRIPTION
110. ter housing See section 7 2 Remove ratchet mount 3 Attach Service Tool No 113971 to flywheel with three bolts see Figure 10 2 4 Use flat open end wrench Service Tool No 404032 on the square nut on back side of the fixed sheave see Figure 10 3 5 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 1 Remove transmission belt see Page 10 2 2 Remove two screws securing lock plate to end cap assembly see Figure 10 4 A SAFETY WARNING Primary sheave is spring loaded Clamp primary sheaves to gether with strap Service Tool No 261906 before proceeding with following steps See Figure 10 5 3 With flat open end wrench Service Tool No 404032 on inside and socket wrench on outside break loose end cap bolt from main shaft see Figure 10 6 4 Finish removing bolt with strap holding sheave halvestogether Re move end cap assembly 9 Remove strap while pressing movable half of sheave toward fixed half of sheave see Figure 10 7 NOTE Spline wrench service tool Part No 114146 when used with service tool Part No 113971 can be used to remove fixed half of sheave from engine CLEANING INSPECTION AND REPAIR a Clean all parts 1 with T
111. tery posts separately with a soda solution and a wire brush Inspect cables for fraying 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 itis definitely known that some has been lost by spilling If water is added in freezing weather charge the battery to full charge at once Charge ing the battery will mix the water with the electrolyte and prevent water freezing in the battery adie LL ELLE VU 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 43 Note that a 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 Figure 7 43 7 18 Self discharge will cause storage batteries to become discharged and sulphated if they are not properly maintained in storage To minimize self discharge store batteries in as cool a place as possible so long as the electrolyte does not freeze A battery which has been allowed to stand idle for a long period of time may be so badly damaged by sulpha tion that it can never be restoredtoa normal charge condition Batteries should be recharged every 30 days
112. 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 The use of additive compounds such as tune up compounds tonics friction reducing compounds etc is discouraged OMC Accessories Engine Cleaner and OMC Accessories Break In Lubricant should be used as necessary according to instructions See inside front cover for recommended fuel mixture 2 4 FUEL CONDITIONER 2 4 Fuel Conditioner is recommended for added protection to your snowmobile engine It is especially recommended as an additive between extended periods of snowmobile use 2 4 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 vas line freezeup Absorbs moisture and water in fuel system Extends spark plug life by reducing fouling and misfire To avoid cylinder scoring and premature en
113. ticles and blow with compressed air from inside holding nozzle about two in ches from filter DO NOT wash or oil filter element 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 c Drain and clean the fuel tank prior to off season storage Remove straps and turn tank upside down Remove adapter and fuel pick up line in tank to check and clean filter screen If adapter was removed it is not necessary on reassembly that the adapter seat be tight against the end of the threaded boss on the fuel tank Apply G E RTV 102 silastic adhesive sealer on adapter threads and immediately install to fuel tank See Figure 6 10 E E e ASBESTOS SLEEVE 4 6 8 d Clean the tank with gasoline poured through a filtering funnel Cover the fuel line opening and agitate the tank Empty it through the fill opening Then reinstall the tank and hoses See following procedure to install new fuel line tie straps e Check to see there are no leaks at fuel hose connections FUEL LINE TIE STRAP Fuel line tie strap part no 262081 must be replaced with a new strap after its removal
114. ting rod caps n Remove connecting rods from crankshaft Reinstall matched caps on connecting rods Remove rings from pistons DO NOT try to save the rings even when they are not stuck Install a complete set of new rings on every overhaul MOUNTING N 2 BLOCK Open end of wrist pin retainer must face the top of the piston If necessary to remove connecting rods from pistons remove wrist pin retaining rings using screwdriver in slot in piston Press out wrist pin to free piston from connecting rod See Figure 9 8 Piston wrist pin hole marked Loose should be up when pressing out wrist pin to prevent piston damage Crankcase Screws Crankcase Half Primary Drive Side Crankshaft Seal Crankshaft Bearings Shim Crankshaft Needle Bearing Retainer Needle Bearing Connecting Rod Cap Connecting Rod Screw Cylinder Gasket Front Cylinder Spark Plug Compression Relief Valve Crankcase Gaskets Figure 9 9 16 Roll Pin 17 Crankease Half Flywheel Side 18 Fan Housing Outer 19 Fan Housing Inner 20 Cylinder Shrouds 21 Engine Frame 22 Engine Mounting Bolt 23 Rear Cylinder 24 Compression Relief Plug 25 Piston Rings 26 Piston 21 Wrist Pin 28 Retaining Ring 29 Needle Bearing Assem 30 Connecting Rod 9 5 9 6 CLEANING INSPECTION REPAIR When using trichloroethylene as a cleaning agent use in a well ventilated are
115. ue to inherent defects during the first three 3 months of service it will be replaced on a no charge basis Batteries that fail during the balance of the warranty period 15 months in the U S and 6 months in Canada will be replaced on a prorata basis In Canada Prestolite warranty should be handled through the dealer from whom the snowmobile was purchased or through a Prestolite bat tery depot 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 on a 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 mechan ical power which is transmitted to the engine through the starter belt The starter switch controls the operation by activating the starter sole noid which makes and breaks the high current circuit between the bat tery and the starter motor The starter solenoid see Figure 7 44 closes the circuit through 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 pul
116. uel inlet screen should be cleaned annually To clean screen remove fuel line and fuel inlet elbow Do not remove screen See page 6 7 for replacement of fuel line tie straps Figure 12 1 gt gt GASKET Figure 12 2 12 5 17096 12 6 STORAGE PREPARATION FOR STORAGE a C Add one ounce of 2 4 fuel conditioner to each gallon of gaso line in tank and mix thoroughly Run engine afew minutes until mixture is in fuel lines and carburetor where it can prevent cumming of check valves and carburetor jets Wash machine Be certain to hose out undercarriage Clean seat ing with automotive foam type upholstery cleaner Treat engine with OMC Accessories Engine Cleaner Remove fuel pump filter screen and clean or replace See Page 12 5 Remove air filter run engine with neutral control knob pulled out and inject OMC Rust Preventative Oil with oil can rapidly into carburetor until engine stops Turn off ignition Clean air filter If compressed air is available blow from the inside See Figure 12 1 Block rear of unit off ground to take weight off track Clean carburetor fuel filter screen See Page 12 5 Drain and clean fuel tank see Section 6 Provide for proper battery maintenance as described in Section 7 Remove transmission belt See Section 10 Rub bottom of skis and other unprotected surfaces of vehicle with cloth saturated in OMC Rust Preventative n Store in dry wel
117. use of their importance to the operation of the engine Ses Section 3 for a discussion ignition theory and Section 7 for complete ignition system analysis 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 NEW VEHICLE DELIVERY Complete instructions for putting new snowmobile into operation are included 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 a reminder of important things to check when putting a new snowmobile into op eration Be sure spark plugs are installed and tightened securely with spark plug gaskets in place b Be sure spark plug wires are securely attached to spark plug ter minals Be sure the correct 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
118. w engine to warm up before putting vehicle in gear Start out slowly avoid jack rabbit starts DO NOT overspeed engine Op eration in extreme cold weather can cause a slow down in the drive and track mechanism When this occurs block up rear of snow mobile 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 9 12 d Observe fuel mixing precautions as described in Section 12 IMPORTANT Adjust drive chain tension after the first 10 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 MUFFLERS AND EXHAUST MANIFOLDS REMOVAL 1 Disconnect positive battery lead for safety purposes Remove engine cover and lower engine cover mounting bracket 2 Remove heat shield 3 Remove belt guard and transmission belt See Section 10 4 Remove two screws 5 and two screws 6 and remove upper muffler 7 Remove two screws 8 to disconnect lower muffler from manifold See Figure 9 23 Remove Power Pack I engine cover 5 Remove four engine mounting nuts and move engine a few inches to rear on chassis 6 Remove steering tie rods from steering column bracket 7 Remove three screws 9 securing lower muffler Work muffler out of well REASSEMB
119. w lead from positive terminal of rectifier B Connect positive DC ammeter lead to positive terminal of rectifier C Connect negative ammeter lead to yellow lead removed in step A Run engine to 4500 RPM with key switch in position Am meter should read 4 amps Turn ignition switch to lights position ammeter should read 11 amps at 4500 RPM ALTERNATOR Figure 7 55 7 23 7 24 CHECKING RECTIFIER DIODES Use ohmmeter to check for shorted or open diodes This is basically a continuity test Disconnect all leads from rectifier assembly Check a diode by connecting test leads to adjacent terminals on rectifier assembly and noting the reading see Figure 7 56 Reverse the test leads and again note the reading If both readings are very low or if both read ings 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 Connect leads to correct terminals See Figure 7 57 and wiring diagram at end of manual ALTERNATOR AND CHARGE COIL REPLACEMENT SEE CHARGE AND ALTERNATOR SYSTEM REPAIR BLOCKING DIODE TEST a Remove diode leads and connect continuity meter between gray and yellow lead Reverse leads and note reading Meter should read in one direction only b Repeat blocking diode test on gray and blue lead Meter should read in one direction only c Repea
120. with a 1 8 drill Drilling too deeply may ruin the casting or the ball check valve Usea small punch to remove the plug Figure 6 3 TOO HIGH DEPRESS HERE MEN PUSH TAB DOWN CHAMBER WALL TOO LOW DEPRESS HERE INLET PRY UP HERE CONTROL LEVER Figure 6 4 E METERING CHAMBER WALL INLET CONTROL LEVER Figure 6 5 Inspect the idle by pass holes to insure they are 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 Replace 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 t
121. xternal bolts nuts and screws and retorque spark plugs to specified torque track tension and ski alignment see Section 11 Start engine and allow to warm up Check track alignment see Section 11 Repeat test run on vehicle Check carburetor needle adjustments 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 COMPRESSION CHECK 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 IN Turn the engine over quickly three or four times with the manual starter Compression should be 105 pounds per square inch minimum IGNITION TIMING CHECK See Section 7 for procedure to check spark timing COMPRESSION RELEASE VALVE ADJUSTMENT Check for 1 32 to 1 16 clearance when compression release knob is pushed in See Figure 5 3 Turn out on jam nut and correct clearance with adjustment screw shown in Figure 5 4 Operate compression re lease knob to check for binding in cable Lubricate the compression release actuator with OMC Grease 114154 CARBURETOR ADJUSTMENTS HIGH SPEED NEEDLE VALVE

1973 J30-253E - Vintage Snow

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