SERVICt:: TEXTBOOK
Contents
1. jet Air screw Float a N Needle valve LX uU 1 Pilot jet Needle jet n E E wre Main jet i Starter jet Fuel Air Mixture lt a The functions of the Mikuni carburetor can be divided into the following Pilot system main system float system and choke system PILOT SYSTEM IDLE The pilot system consists of the pilot jet air screw pilot outlet and bypass The ratio of the air fuel mixture is controlled by adjusting the air screw MAIN SYSTEM The main system consists of the air jet jet needle needle jet main jet and throttle valve The ratio of air fuel mixture is controlled by the jet needle and needle jet at mid range and by the main jet at top end FLOAT SYSTEM The float system consists of 2 independent floats and needle valve The indepen dent float system along with a fuel surface stabilizing plate maintain and stabilize the fuel at a constant level CHOKE SYSTEM Fuel Enrichener The choke system consists of the starter jet and starter plunger This system meters additional fuel through a completely separate system thus eliminating the need for a choke valve in the bore of the carburetor igs EXPLODED VIEW OF MIKUNI VM 36 45 I 1 C 13 Swivel Adapter Lock Nut Cap Gasket Throttle Valve Spring Plate E Ring Jet Needle 6DH4 Throttle Valve 3 0 Needle Jet 4 1592. DIES T 5 NE i TIMING LIGHT E j o e t 5 7 la 7 Connect a timing light to No 1 spark plug lead and to a 12 volt battery as shown above NOTE c amp on type timing Light such as Merc 0 Tronic Model 712 pictured above is preferred CD ignition can damage standard timing Light HISEL MARK EE BJ FELT PEN 8 Start engine and run at idle MARK 9 Aim timing light at flywheel Marks 1 Remove coolant pump cover Using a should align small chisel carefully mark the lip of crankcase by flywheel as shown 10 If not remove flywheel and alternator above stator Loosen 4 screws securing timing ring and rotate as necessary 2 Install dial indicator in No 1 Clockwise rotation retards timing spark plug hole counterclockwise rotation advances timing Retighten screws securely 3 Rotate crankshaft to locate TDC Top Dead Center and zero dial indica 11 Reassemble and recheck timing tor 4 Rotate crankshaft counterclockwise opposite normal rotation until dial indicator reads 0 065 inch BTDC Before Top Dead Center 5 With flywheel in this position place a mark with felt pen on flywheel corresponding with chisel mark 6 Remove dial indicator and reinstall spark plug 19 POWER TRAIN 10265 COMET CLUTCH 1 Cap Screw 6 used 7 Guide Button 6 used 13 Pivot Pin 3 used 2 Pilot Washer 8 Thrust Washers 14 Steel Washer 6 used 3 Cover Plate w
3. Use ethylene glycol anti freeze mixed 50 50 with clean water This provides protection to 40 Fahrenheit Do not use rust inhibitors stop leak or any other additives in the cooling system Draining System Remove radiator pressure cap and remove lower engine hose to drain block Flush sled with water after draining Cleaning System After draining remove radiator hoses and back flush radiator with clean water Do not use flushing additives Filling System 1 Remove bleed screws from cylinder head 1 and radiator 2 Fill system until coolant runs out cylinder head bleed port Install bleed screw and continue to fill until coolant runs out radiator port Install final bleed screw and fill radiator to top continue to fill until coolant runs into coolant recovery container Approx 1 2 full Install pressure cap 3 Run for 5 minutes or to 140 on temperature gauge Let cool and check coolant for proper level NOTE The cooling system pressure test et shown in the following tests 45 a Standard automotive unit available through Deere Gard as number JDM 77 TESTING PRESSURE CAP PRESSURE CAP a 1 Install radiator pressure cap into tester as shown above 2 Apply pressure to cap Air should not leak past cap seal until 14 17 psi is reached If it does replace cap TESTING SYSTEM 1 Connect pressure tester to radiator as shown above 2 Pressurize system to 20 psi and shut off val
4. Rubber Cap Plunger Fitting Choke Lever Leaf Spring 28 Plunger Spring 29 Plunger 30 Air Screw Spring 3 Air Screw 32 Vent Tubes 2 33 Hex Screw Plug 34 Air Jet 0 7 35 Tube Fittings 2 used 36 Throttle Stop Screw 37 Stop Screw Spring 38 Gaskets 2 used 39 Baffle Plate 40 Pilot Jet 50 MY 2 Gasket Needle Valve Assembly Float Arm Pin Float Arm Caps 2 used Floats 2 used Flat Washer Main Jet 240 Float Body Gasket Drain Plug Screws 4 used Body CHOKE SYSTEM PLUNGER SEATING SURFACES STARTER PLUNGER The choke system meters additional fuel for starting a cold engine As the system requires negative pressure in order to function the throttle must be closed when starting IMPORTANT If the starter plungers do not properly seat when shut off the carburetors will run RICH adversely affecting the other systems Remove starter plungers from carburetor body Check plunger seating surface for particles or deterioration that could cause leakage Also check seating sur face in carburetor body Reassemble and check plungers for free operation and adequate retention in the OFF position ADJUSTMENTS Float Level Adjustment FT 3 pem Check float adjustment as follows 1 Remove the float chamber body from the carburetor 2 Invert the carburetor The float arm should be parallel to the float chamber seating surface
5. This setting provides minimum turning radius Inner Hole B Use for high speed running This setting increases turning radius but reduces effort and provides a better feel of steering control 383 INSTALLING SKIS 1 Thread in attaching cap screw until tight 2 Back off approximately 1 4 turn or until ski pivots freely 3 Install and tighten jam nut WEAR RODS Standard equipment wear rods are steel Carbide wear rods are available See page 29 SKI POSITIONS a oo HOLE The ski saddle can be placed in either of two positions Rear Hole Use for general snowmobiling This position provides easiest steering Front Hole Use for high speed running This position increases ski castor thus reducing darting Steering effort is slightly increased 29
6. Bushing 9 Roller Pin 15 Arms Mod F 3 used 4 Cover 10 Spacer Washer 2 used 16 Steel Washer 3 used 5 Spring Brown 11 Movable Face 17 Spring Pin 3 used 6 Spider 12 Movable Face Bushing 18 Fixed Face w Hub Clutch Engagement 4000 rpm Governed Engine Speed 8000 8500 rpm At full upshift engine may run 500 1000 rpm past maintenance speed depend ing on operating conditions and gearing The modified F arms are notched to pro vide better acceleration The clutch engages only slightly at 4000 rpm and does not shift hard until approximately 6000 rpm is reached This prevents the engine from bogging at clutch engage ment SERVICE Use JDM 41 A clutch tool set for removal disassembly assembly and installation Refer to Cyclone and Liquifire Service Manual SM 2108 for procedures LUBRICATION Duralon bushings keys 3 9 and 12 do not require lubrication Lubricate cam arms and pivot pins keys 13 and 15 with silicone spray or Never Seez Lubricant NOTE Use Loctite grade AV Red on Spider and hub threads INSPECTION Movable Face Bushings keys 3 and 12 check for excessive clearance with hub key 18 which causes vibration binding and a loss of engine maintenance rpm Roller Bushings keys 8 and 9 check rollers for freeness and excessive clear ance Excessive clearance puts arm in wrong relationship with roller thus affecting performance Cam Arms key 15 Check for
7. Transformers Coils Surface Gap Spark Plug Triggering Slot Magnetic Flywheel Rotor Ignition Timing Rotor Alternator Stator Ignition Timing Ring UN ng 6778 by ge Principle of Operation The Prestolite Electromag C D ignition system is a combination permanent magnet flywheel alternator and solid state breakerless capacitor discharge ignition system The electromag is designed to supply the high voltage of the ignition system as well as generate the current required for lighting systems In operation the flywheel rotor 1 which incorporates a special flexible magnet and is mounted on the engine crankshaft revolves around the alternator stator 3 which is fixed to the engine Current is generated in the windings on the twelve poles of the stator plate nine of which supply power for the lights and three of which supply power for ignition The electronic module 5 incorporates the ignition capacitors and the necessary solid state circuitry for charging and discharging them The timing rotor 2 revolv ing within the timing ring 4 triggers the discharge of these capacitors through the electronics module to the ignition transformers 6 which step up the voltage to a level necessary to insure successful firing of the surface gap spark plugs 7 The special configuration of the triggering slot 8 in the timing rotor controls the electronic timing advance 17 The triggering slot gener
8. free operation If arms contact sides of spider key 6 replace movable face key 11 to reduce side clearance between guide buttons key 7 and movable face 99 SECONDARY SHEAVE 1 5 16 x 1 Cap Screw 3 used 5 Torque Button 3 used 9 Shim 0 030 inch 2 Minlon Bushing 6 Fixed Sheave and Post 10 Shim 0 040 inch 3 Cam Bracket 382 7 Elastic Lock Nut 12 used 11 Duralon Bushing 4 Spring Blue 8 Button Head Screw 12 used 12 Movable Sheave SERVICE PRETENS ION Refer to Cyclone and Liquifire Service The spring is factory assembled into the Manual SM 2108 for disassembly bushing No 2 hole in the cam replacement and assembly procedures It may be found necessary to pretension INSPECTION the spring differently to maintain an engine speed of 8000 8500 RPM when at Inspect movable sheave and cam bushings full throttle key 2 and 11 for excessive clearance with post key 6 Excessive clearance This becomes necessary with changes in will cause binding with resulting erratic temperatures and or altitudes which affect engine horsepower performance LUBRICATION Less pretension lowers engine maintenance speed more pretension increases engine No lubrication is required speed not adjust to provide engine speed in excess of 8500 RPM PRETENSION CHART Pounds of spring Insert spring tang Place cam and spring over Degrees of spring in cam hole number fixed face hub with tang pretension te
9. lean Removal of silencer will not improve performance To change the main jet remove the drain plug from the bottom of the float cham ber body This provides access to the main jet NOTE Increased altitude Less fuel increased temperature Less fuel IMPORTANT For maximum durability the jetting should be as rich as possible NOTE Aways check for air Leaks around for satisfactory performance Indica boots caused by improper assembly tions of engine running lean can be Leaning out may occur if boots are not noted by a very light coloring in the checked exhaust manifold or very light color on the spark plug insulator 1 ALTERNATOP STATOR U fellow Green L3 N Comer White freen Red Blue Yellow Black CONNECTOR White TETHER SWITCH ENGINE COUPLER ELECTRICAL SYSTEM WIRING DIAGRAM STOR TAIL HEADLIGHT LIGHT Black BRAKE T L LEAD MAIN WIRING HARNESS VOLTAGE fireen REGULATOR TERMINA White BLOCK Black Vo tlow rt 5 8 HEADLIGHT BRAKE LIGHT SWITCH SWITCH POSITION CLOSED OPEN POSITION CLOSED OPEN KEY SWITCH KILL SWITCH 16 YELLOW W BEN ES Led Yellow On LNW STRIPE Yellow QULAN EMP B c HEADLIGHT DIMMER SWITCH POSITION CLOSED 2PEN Aj C IGNITION SYSTEM 2 0 e ALTERNATOR IGNITION LEADS STOP LEAD Electronics Module Ignition
10. wheels This p SCREW d clearance should be equal on both NT sides of wheels 3 A track will run to the loose side If idler wheels are not centered between drive lugs adjust track tension as required to equalize 4 Repeat steps 1 2 and 3 until idler jh THER wheels are centered between drive lugs 1 Securely support rear of snowmobile FRONT PIVOT so track is off ground 2 When properly tensioned top of track drive lugs midway in span should be flush to 1 4 inch below bottom of wear bars as shown above to decrease tension Adjust each side as required Tighten lock nuts after making adjustment 3 Turn adjusting cap screws clockwise Non eaa N P to increase tension counterclockwise eem diae LOWER ae ems TRACK ALIGNMENT The front pivot can be placed in either of two positions in the tunnel Track alignment should always be checked after adjusting track tension Lower Hole This position provides best ride and should be used for general snow mobiling Upper Hole This position provides easier ski lift and should be used when riding in deep snow conditions NOTE Check track tension after changing pivot position 2 26 SLIDE SUSPENSION WITH OPTIONAL WHEEL KIT STEERING RESPONSE SKI LIFT 1 Backing screws A Out increases ski lift turning them in decreases lift 2 Never back out screws more than the following Fron
11. 140 65332 380 66333 150 65333 390 66334 John 160 M65334 400 M66335 Mikuni Deere 170 M65468 410 M66336 180 M65469 420 M66497 0 5 M66884 190 M65470 430 M66498 1 0 M66885 200 M65471 440 M66500 1 5 M66886 210 M65472 450 M66824 2 0 M66887 220 M65852 460 M66907 2 5 66658 230 65882 470 M66908 3 0 M66888 240 M65853 480 M66909 3 5 M66889 250 M65854 490 M66910 260 M65855 500 M66911 270 M65883 Main Jet Selection The main jet meters fuel through the carburetor when operating in the 1 2 to full throttle range Temperature and altitude affect the density of air order to maintain a constant air fuel ratio which results in peak performance the carbure tors must be jetted richer or leaner for varying conditions John John John Needle Jets Deere Pilot Jets Deere Air Jets Deere 0 0 M66890 15 66912 0 5 66499 0 2 66891 17 5 M66913 0 6 M66917 0 4 M66892 20 66745 0 7 66033 0 6 M66893 25 M66929 0 8 M66918 0 8 M66739 30 M66844 0 9 M66919 P 0 M65340 35 M66914 1 0 M66920 P 2 M66845 140 M65355 1 2 M66921 P 4 M66894 45 M66746 1 4 M66922 P 6 M66741 50 M66663 1 6 M66923 P 8 M66895 55 M66672 1 8 M66924 Q 0 M66740 60 M66915 2 0 M66925 Q 2 M66896 Q 4 M66897 Q 6 M66898 Factory Installed Q 8 M66916 CHANGING MAIN JET INTAKE SILENCER Periodically inspect foam filter for accumulation of debris or ice which could hamper performance IMPORTANT Never run engine without silencer as engine will run
12. Pants not shown Kit Parts New front frame New engine base plate and mounts New fuel pump bracket New aluminum belt guard and bracket New snow flap and support 6 New drive belt 7 New reinforcement R H 8 Bag of parts Includes the following new tensioner and spring assembly new ski bolts rail reinforcement bars torque buttons new brake pads new chain case cover seal all new hardware washers bolts nuts cotter pins and pop rivets The above parts will be installed on 11 snowmobiles In addition the suspension and other related components will be checked for cracks and welded if neces New coolant will be added to the cooling system Chaincase oil will be replaced and the secondary torque buttons will be epoxied in place The snowmobile will be run on chassis dyno for final performance check SPECIFICATIONS COMPONENT ITEM SPECIFICATIONS ENGINE Manufacturer JD Kioritz Model KEC 340 RS 24 LC No of Cylinders 2 Bore 60 mm Stroke 60 mm Displacement 339 cc Cooling Liquid Carburetor Mikuni VM 36 2 used Fuel Mixing Ratio 50 1 WICO Capacitor Discharge Champion QN 19V AM53787 0 065 inch 179 BTDC 120 Watt FUEL SYSTEM ELECTRICAL SYSTEM Ignition Spark Plug Timing Dynamic Lighting Coil Capacity Comet 102CS John Deere 4000 rpm Max 8000 8500 rpm POWER TRAIN Clutch Se
13. UP DATED SERVICE TEXTBOOK for JOHN DEERE 340 Liquidator Litho in U S A I 6 M67054 CONTENTS LIQUIDATOR PROGRAM 270M 1 SPEGIFTCATIONS 3 ENGINE 5 FUEL SISTEM cass casa dun 10 ELECIRICAL SYSTEM o V Un 11 POWER TRAIN 2 2 1 20 SUSPENSION 552 02 525 552555295222 26 LIQUIDATOR REBUILD PROGRAM 270M 1976 340 Liquidator Serial No 55 001 70 000 The 1976 340 Liquidator did not perform as expected resulting in some dissatisfied customers This rebuild program was implemented to correct the premature piston scoring clutch failure and structural failures encountered in this past season The following parts are listed for your information as to what went into your 1976 Liquidator under the rebuild program 2 3 4 5 6 EC ERES I te cS Engine Kit Parts New specially cammed pistons with rings New cylinder assembly with new bore size New gaskets New piston pin needle bearings New thermostat Carburetor main jet changes Improved cooling system by pass and all new hoses 8 9 10 13 14 New primary drive clutch Improved carburetor venting New rebuilt water pump Rebuilt and new ignition system New fuel pump and hoses New carburetors See page 1l for new parts added New lower engine hose
14. ates voltage in the trigger coils operation the shallow portion of the triggering slot passes the trigger coils first TRIGGER PICKUP COIL IN TRIGGER HOUSING Lp STATIONARY TRIGGER ROTOR LOW RPM HIGH RPM TRIGGERING TRIGGERING However at low RPM the voltage genera ted by the shallow portion of the slot is not sufficient to trigger the elec tronics module Therefore the trigger ing is accomplished at the deep slotted portion As engine speed increases to approximately 1000 RPM the voltage generated by the shallow portion of the triggering slot becomes sufficient to trigger the electronics module thereby amp dvancing the timing 15 degrees The retarded position allows easier starting PRELIMINARY CHECKS CAUTION High Energy Ignition System can produce injurious elec trical Shock Do not hold spark plugs leads connectors in hand with engine running when checking for spark Check the black plug in connector by electronics module to make certain con nections are clean and tight Check for broken leads and leads with damaged in sulation Check for clean and tight ground connections Using a test plug check for spark dis charges at both cylinders If spark discharges are observed for both cylin ders the problem lies elsewhere in the engine However if engine starts but will not run over 2500 3500 RPM the high speed windings on the stator or the electronic modul
15. condary Clutch Engagement Engine Maint Speed Final Drive Ratio Standard 1 86 1 Optional 1 67 1 2 0572 2 47 1 Brake Mechanical Disk Drive Belt M66345 Slide Wheel Kit Optional Gates Poly Grouser 15 4 inches 121 73 inches 3 29 pitch TRACK AND SUSPENSION Suspension Type Track Width Length CHASSIS AND BODY Material Tunnel and Pan Aluminum Hood Fiberglass Windshield Polycarbonate Overall Length 107 5 in Overall Width 40 in Overall Height 39 in Ski Stance 32 in Wheelbase 72 in Weight 155 w coolant 500 155 CAPACITIES Fuel 8 00 U S Gallons Type Premium Grade Coolant 4 0 Quart Type 50 50 Solution Ethylene Glycol Water 5 ounces SAE 30 Chaincase With John Deere snowmobile oil and Premium Grade gasoline Use 40 1 ratio for first tankful DETAILED ENGINE SPECIFICATIONS ITEM NEW PART WEAR DIMENSION TOLERANCE 2 365 to 2 366 in 2 37 in Connecting Rod Small End 0 9058 to 0 9063 in 0 9071 in Connecting Rod Side Clearance Large End 0 013 in 0 024 in Crankshaft Runout Max 0 003 in Crankshaft End Play Max 0 024 in Piston at Skirt 2 3575 to 2 3583 in 2 350 in Piston Pin Bore 0 7476 to 0 7487 in 0 7500 in Piston Pin 0 7477 to 0 7480 in 0 7461 in Compression Pressure 110 to 130 psi heec 1 Check compression with engine cold and throttle in wide open p
16. e could be at fault If spark discharges are not observed at the test plug make certain the problem is not defective switches This can be accomplished by uncoupling the large white coupler located above the electronit module and repeating the check for spark discharges This removes the key switch kill switch and tether switch from the system If all checks to this point indicate a faulty ignition system it is recommended that either an ohmmeter or the JDM 74 Tester be used to locate the faulty com ponent TEST PROCEDURES See Cyclone and Liquifire Service Manual SM 2108 for JDM 74 Tester diagnostic procedures SPARK PLUGS BRAND PART NUMBER QN 19V AM53787 A surface gap spark plug with a sooty appearance does not mean the plug is mal functioning as CD ignition is capable of firing a plug in this condition If the insulator around the center elec trode appears tracked replacement is not necessary unless the tracking develops into a deep channel which can cause misfiring If the center electrode is burned back 1 32 inch below the insulator the plug should be replaced Spark Plug Color Read the entire firing end of the plug not just the insulator as in conventional plugs CONDITION oo Lean COLOR Dark Brown Light Brown Black 18 IGNITION TIMING ru Check and adjust ignition timing as follows CS Sees 5 DIAL INDICATOR
17. ith the top of the housing 3 Press pulley bracket onto bearing shaft until flush 4 Press impeller onto bearing shaft until approximately 0 009 inch clearance is provided between im peller and housing Impeller must rotate freely after assembly EXHAUST SYSTEM Wrap handle with tape 32 brazing rod Loop Overall length 8 12 The tool pictured above can be easily constructed for removing or installing exhaust system springs quickly and safe ly Hook the loop of the tool on the spring and pull to hook or unhook springs REPLACING PISTONS OR CYLINDERS Disassembly 1 Drain coolant and remove exterior components carburetors coolant pump and exhaust manifold 2 Remove cylinder head and cylinders exposing pistons 3 Remove pistons using JDM 7 Piston Pin Set Repair 1 Clean aluminum off cylinders if necessary using sodium hydroxide Lightly hone to remove score marks Clean with soap and water after honing 2 Check piston and cylinder clearances See specifications on page 3 Assembly Clean up gasket surfaces and use new gaskets when assembling Coat all mov ing parts with snowmobile oil prior to assembly 1 Heat piston by placing on a 100 Watt light bulb 2 Install pistons IMPORTANT To prevent piston ring ends from hook ing the exhaust port position piston so the ring retaining pins are on the intake side 3 Install cylinder assembly being certain rings are pr
18. nsion when on spring in hole of fixed measured at sheave face Rotate cam clockwise past the ramp indicated INSTALLING ALIGNMENT TOOL gt Slide tool over the secondary shaft If center distance is correct the tool notch will fit over drive sheave hub Alignment and 1 30 offset are correct when the tabs are flush with engine side of fixed face Adding or removing shims on secon dary shaft will change offset If center distance or alignment is incorrect loosen four engine mount ing bolts located under engine base plate Align engine to driven clutch Tighten four mounting bolts Remove tool 11 47 JDM 81 CHECKING CLUTCH ASSEMBLY Alignment tool JDM 81 will check three dimensions 1 2 3 E p Center distance is 11 47 Sheave alignment and 1 30 offset is checked at tabs Secondary shims are measured with end of tool BRAKE ADJUSTMENT 1 Adjust jam nuts on cable A as required to make cam arm point straight forward horizontal 2 Adjust nut B as required to provide 1 to 1 1 2 inches between brake lever and grip when brake is applied LUBRICATION Remove cam arm 2 Remove two pins 3 Lubricate pins with Never Seez Lubricant Reinstall pins rounded ends facing outward 5 Reinstall cam arm and adjust tension as sho
19. ntrol and place Air Flow Meter JDM 64 2 over carbure tor throat Tube must be in a vertical position 7 Slowly close air flow control until float in tube lines up with a graduated mark on tube e 78 E x AIR FLOW CONTROL Turn swivel 9 counterclockwise 10 STOP Place air flow meter on second carbu retor without changing adjustment of air flow control Adjust throttle stop screw on second carburetor to bring float to same level as in step 7 Support machine so track is off ground Start engine and run at 4000 rpm Place a wedge in throttle lever to maintain engine at this rpm Use Air Flow Meter as in steps 6 8 to determine if carburetors are synchronized at this rpm not turn swivel adapter counterclockwise on carburetor with lowest float level until float levels match NOTE Hold ain ow meter ton just Long enough to get a reading I placed over carburetor too Long engine will falter MIKUNI JOHN DEERE PART NUMBERS Main Jets Available Jet Needles John John John Jet Deere Jet Deere Mikuni Deere 70 M66899 280 M65884 6DH3 M65354 75 M66900 290 M66324 6DH2 M66656 80 66901 300 66325 6FL14 M66422 85 M66902 310 M66326 6DP 1 M66926 90 M66903 320 M66327 6DH7 M66927 95 M66904 330 M66328 6DH4 M66928 100 M66905 340 M66329 6DP5 66941 110 66906 350 66330 120 65336 360 66331 130 65335 370 66332 Throttle Valves 36
20. o provide increased life 9 PTO Seal Guard To protect seal from failed drive belts and to better retain the seal IMPORTANT Due to the high output of this engine the following precautions must be taken to prevent engine failure 1 Use only Premium Grade leaded gasoline 2 Mix gasoline and oil in a 50 1 ratio 40 1 for first tankful 3 Proper break in is critical DO NOT exceed 40 mph for the first 25 miles nor force machine at full throttle in deep snow An occasional burst of full power on hard packed snow will not be harmful 4 Always warm up engine prior to making a high speed run 5 Keep cooling system full coolant pump belt tight and radiator clean Never allow temperature gauge needle to move out of yellow and into red zone Shut down or increase travel speed with reduced load if this occurs COOLING SYSTEM Operation The normal flow of coolant is from the radiator to the coolant pump through the cylinders and cylinder heads across the thermostat and then back to the radiator for cooling When the thermostat is closed below 1409F coolant is not circulated through the radiator pump circulates coolant through only the engine using the by pass hose When system pressure builds beyond 14 17 psi cap pressure some coolant passes the pressure cap and is caught in the coolant recovery container When the system cools this coolant is pulled back into the radiator Coolant
21. on the carburetor body as shown above 3 Bend needle valve actuating tab if necessary to make parallel Jet Needle Adjustment The jet needle can be set in one of 5 different settings to fine tune the mid range mixture ratio This setting does not affect idle or full speed operation The E ring is factory assembled in groove No 2 Groove No 1 provides leaner mid range operation groove No 5 provides richer midrange operation FS x SYNCHRONIZING THE CARBURETORS gt EXT 73 Sia THROTTLE cig gt 9 xi b 1 Clamp the throttle lever in the full 8 throttle position using either a strong rubber band or clamp 2 Loosen lock nuts A adapters B clockwise or counter clockwise as required to make back edge of throttle valves intake side flush with top of carburetor bore 3 Then back out swivel adapters B counterclockwise five complete turns This will completely open valves making them flush on front engine side 4 Carefully seat air screws C Back out 1 1 2 turns counterclockwise 5 Remove clamp from throttle and start and warm up engine Turn throttle stop screws equally clockwise to raise idle speed to lower speed be 2200 2500 rpm Idle speed should NOTE It may be necessary to adjust ain screws C slightly to provide Smoothest idling Turn serew out to Lean mixture and in to enrichen mixture 6 Open air flow co
22. operly positioned on pistons 4 Install cylinder head and torque nuts in sequence shown on page 3 5 Reinstall exterior components REPLACING CRANKSHAFT Disassembly 1 Remove cylinder assembly and pistons 2 Remove recoil starter flywheel stator and timing ring 3 Separate crankcase halves using a mallet if necessary and lift out crankshaft Repair 1 Check condition of seals and bearings Outer bearings PTO or flywheel end can be removed using Deere Gard puller set D 01049AA 2 New bearings can be installed after heating inner race on a 100 Watt light bulb Note position of outer race retaining pins Pins must be to outside 3 Check crankshaft runout end play and connecting rod side clearance See specifications on page 3 BEARING RETAINERS rine 4 2 B ye 2 Y r LV m jw BEARING NES OUTER RACE PINS Assembly 1 Install crankshaft into upper crankcase half Be certain seals and bearing re tainers are properly positioned and that bearing outer race pins are in notches as shown above P 2 Coat sealing surfaces with a thin coat of RTV sealant M64850 Install lower crankcase half and torque to specifica tions in sequence See page 3 FUEL SYSTEM CARBURETOR E Jet needle e W ba n By pass Starter T im plunger li l hrottle valve 2 Pilot outlet c i
23. osition Pressure should not vary by more than 10 psi between cylinders Cylinder Bore TORQUE SPECIFICATIONS TORQUE SEQUENCE Cylinder Heads 8 mm 175 in lbs 10 mm 260 in 1bs Crankcase 260 in 1bs 1 60 ft lbs ENGINE The Kioritz 340 RS 24 LC engine is a totally new engine in the John Deere line and has the following features 1 3 Liquid Cooling This results in increased and more consistent power output increased reliability better fuel economy and lower sound levels Twin Carburetors The two VM 36 Mikuni slide valve carburetors pro vide better breathing for increased power Capacitor Discharge Ignition Wico CD ignition provides quicker starting reduced plug fouling and features surface gap spark plugs to eliminate spark plug induced pre ignition Piston Ported To provide high out put at high rpm Twin Expansion Pipes To provide a broader power band Forged Pistons these feature high strength high silicone aluminum alloy with specially cammed and profiled skirts Skirts are finished with a waved surface for better oil retention and lower friction Two chrome half key stone piston rings are fitted for improved sealing and life See Page 9 7 Crankshaft The crank is fitted with six main bearings for better support and features full circle throws for better balance and breathing 8 Cast Iron Liners T
24. t Pivot in Lower Hole 0 23 inch Front Pivot in Upper Hole 0 30 inch NOTE These dimensions measured underside of adjusting screw head to of jam nut SUSPENSION SPRINGS 1 Loosen nuts B to soften rear pivot springs tighten nuts to stiffen Adjust as required to prevent bottom ing 2 Loosen nuts C to soften front pivot springs tighten to stiffen If a still softer setting is desired remove one spring from front pivot Adjust remaining spring as required GROUSER BAR REPLACEMENT 1 Chisel off rivets and remove damaged grouser bar NOTE Do not chisel on the nivet head as damage to the track could easily result BACKING PLATE STAINLESS STEEL POP RIVET 2 Install new bar securing with stain less steel pop rivets and backing plate Kit AM54160 contains the special stainless steel pop rivets and backing plates E a SKIS AND STEERING TIE ROD SKI ALIGNMENT 1 Adjust skis parallel by adjusting tie rod 2 Adjust drag link as required to align handlebars with skis STEERING ARMS 1 With skis parallel and pointed straight forward steering arms should be positioned on spindles to provide approximately 5 9 inches between steering arms and front frame as shown above L _ 1 5 16 CENTER STEERING ARM The drag link can be placed in either of two positions on the center steering arm Outer Hole A Use for general snowmo biling
25. ust not protrude through sprockets LUBRICATION m FILL PLUG VENTED LEVEL PLUG 1 Remove fill and level plugs 2 SAE 30 oil through fill hole until it runs from level hole 3 Install plugs NOTE To prevent oil spewage it 45 tant that in cover seak be placed as Shown above and that vented p ug is installed the upper hoe 24 LOWER SPROCKET SPACERS Short Spacer M66133 is 1 27 35 39 amp 42 Tooth 40 Tooth Sprocket Sprockets Long Spacer 66346 FINAL DRIVE RATIOS Upper Sprocket Chain Length No of Teeth No of Pitches Ratio DRIVELINE CROSS SECTION uz ji J 4 bo 27 1 QE v7 SA S EEDA SZ j _ 7 8 POU ASSES HI Mud 5 gt M Sy SSS L58 5 SUSPENSION ADJUSTMENTS TRACK TENSION 1 With rear of snowmobile securely supported start engine and run track The following procedure is the preferred for short time Let track coast to a method of adjusting track The method stop DO NOT apply brake as this can described in the operator s manual cause track to go out of alignment should be used only if facilities do not permit use of preferred method 2 Check clearance between track drive E ES TENSION lugs and rear idler
26. ve 3 If system will not hold 20 psi with out leakback look for leaks at hose connections coolant pump cylinder heat etc REPLACING THERMOSTAT 1 Drain system 2 Remove outlet housing and remove thermostat 3 Thermostat can be tested as follows a Suspend thermostat and thermo meter in a container of water b Heat and stir water c Thermostat should begin to open at 14092 It should be fully open approx 1 4 inch at 162 F d Remove thermostat and observe closing 4 Reinstall in opposite order using a new gasket certain tempera tures sensing portion of thermostat is installed into cylinder head as shown above P PUMP BELT TENSION 1 Remove pump cover 2 Belt should deflect no more than 3 8 when deflected midway between sheaves 3 Tighten belt by loosening three pump attaching nuts and pivoting pump upward at rear Tighten nuts PUMP REPAIR 1 Cap Screw 6 Housing 2 Cover 7 Bearing 3 Gasket 8 Pulley Bracket 4 Impeller 9 Pump Bleed 5 Seal 10 Pump Bleed Hose A pump repair kit is available and consists of an impeller gasket seal and bearing Disassembly 1 Remove pulley bracket by pressing shaft out of bracket 2 Press the bearing seal and impeller out bottom of housing 3 Press bearing out of impeller Assembly 1 Press new seal into housing 2 Coat bearing with light oil and press bearing outer race until it is flush w
27. wn above bY 1 Nut 7 Plate 2 Washer 8 Friction Pad 2 used 3 Cam Arm 9 Brake Disk 4 Spring 10 Cable Bracket 5 Pins 2 used 11 3 8 x 2 inch Cap Screw 6 Casting 12 Lock Nut 13 Cotter Pin REPLACING BRAKE PADS A brake repair kit is available which includes key 5 7 and 8 1 Remove casting key 6 2 Remove drive chain sprockets and tensioner from chaincase 3 Remove secondary sheave 4 Remove secondary shaft bearing and pull shaft out of chaincase and brake disk key 9 5 Install new parts and reassemble NOTE Lubricate 1 D of brake disk key 9 with Never Seez before installing onto Secondary shaft 23 CHAINCASE SERVICE PIVOT PIN HEAD TENSIONER Removal 1 Remove cap screws securing upper and lower sprockets 2 Remove sprockets drive chain and tensioner as an assembly Installation 1 Check alignment as shown at right Install sprockets drive chain and tensioner as an assembly using JDM82 tool ie NOTE See page 25 for Lower sprockets Spacers SPROCKET ALIGNMENT 1 Install sprockets without chain and tensioner Secure with cap screws 2 Using a 6 inch rule check alignment Place rule on lower sprocket and slide upward 3 Add shims behind upper or lower sprock ets as required to obtain alignment NOTE Do not use than three shims behind upper Sprocket or more than 10 shims behind Lower sprocket Shafts m
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