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Husqvarna Kohler SV470, Workshop Manual

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Husqvarna Kohler SV470 Workshop Manual Download Page 50

7.3

Section 7

Electrical System and Components

7

Electronic CD Ignition System

Figure 7-2. Electronic CD Ignition System.

These engines are equipped with a dependable

electronic, capacitive discharge (CD) ignition system.

The system consists of the following components:

• A magnet assembly which is permanently affixed

to the flywheel.

Kill Switch or Off

Position of Key Switch

Air Gap

0.203/0.305 mm

(0.008-0.012 in.)

Flywheel

Magnet

Ignition Module

Spark Plug

Lamination (A)

Kill Terminal (B)

Spark Plug

Terminal (C)

Spark Plug Boot

• An electronic, capacitive discharge ignition

module which mounts on the engine crankcase.

• A spark plug.

• A kill switch (or key switch), which grounds the

module to stop the engine.

Summary of Contents for Kohler SV470

Page 1: ...Workshop manual Kohler Courage Tractor Engines English ...

Page 2: ...tion 3 Troubleshooting Section 4 Air Cleaner and Air Intake System Section 5 Fuel System and Governor Section 6 Lubrication System Section 7 Electrical System and Components Section 8 Disassembly Section 9 Inspection and Reconditioning Section 10 Reassembly 1 2 3 4 5 6 7 8 9 10 ...

Page 3: ......

Page 4: ...ons should be followed at all times Failure to follow these precautions could result in injury to yourself and others Rotating Parts can cause severe injury Stay away while engine is in operation WARNING Rotating Parts Keep hands feet hair and clothing away from all moving parts to prevent injury Never operate the engine with covers shrouds or guards removed Hot Parts can cause severe burns Do not...

Page 5: ...ine vapors are present Electrical Shock Never touch electrical wires or components while the engine is running They can be sources of electrical shock Explosive Fuel can cause fires and severe burns Stop engine before filling fuel tank WARNING Explosive Fuel Gasoline is extremely flammable and its vapors can explode if ignited Store gasoline only in approved containers in well ventilated unoccupie...

Page 6: ...mmunication involving an engine always give the Model Specification and Serial Numbers of the engine The engine identification numbers appear on a decal affixed to the engine shrouding See Figure 1 1 An explanation of these numbers is shown in Figure 1 2 Figure 1 2 Explanation of Engine Identification Numbers SV540 0001 Figure 1 1 Engine Identification Decal Location Identification Decal MODEL NO ...

Page 7: ...ity of 2 gallons or less with a pouring spout is recommended Such a container is easier to handle and helps eliminate spillage during refueling Do not use gasoline left over from the previous season to minimize gum deposits in your fuel system and to ensure easy starting Do not add oil to the gasoline Do not overfill the fuel tank Leave room for the fuel to expand Fuel Type For best results use on...

Page 8: ... the spark plug blow out the cavity with compressed air Remove the spark plug The spark plug is most accessible when the blower housing is removed for cleaning Add one tablespoon of engine oil into the spark plug hole Install the plug but do not connect the plug lead Crank the engine two or three revolutions Connect the plug lead 5 Reinstall the blower housing if removed previously and torque the ...

Page 9: ...1 6 Section 1 Safety and General Information Figure 1 4 Typical Engine Dimensions Dimensions in millimeters Inch equivalents shown in ...

Page 10: ...0S SV540S 535 cc 32 6 cu in SV590S SV600S 597 cc 36 4 cu in Compression Ratio 8 5 1 Dry Weight 35 8 kg 79 lb Oil Capacity with filter 1 5 L 1 6 qt Angle of Operation Maximum at Full Oil Level All Directions 25 Intermittent Air Cleaner Base Hex Nut Fastener Torque 5 5 N m 48 in lb Mounting Screw Fastener Torque Install Dry DO NOT OIL 8 0 N m 70 in lb Into new as cast hole 5 5 N m 48 in lb Into used...

Page 11: ... 0 25 0 59 mm 0 0098 0 0232 in Connecting Rod to Piston Pin Running Clearance 0 015 0 028 mm 0 0006 0 0011 in Piston Pin End I D New 22 015 22 023 mm 0 8667 0 8670 in Max Wear Limit 22 036 mm 0 8675 in Crankcase Governor Cross Shaft Bore I D New 6 025 6 05 mm 0 2372 0 2382 in Max Wear Limit 6 063 mm 0 2387 in Oil Drain Plug Torque 14 0 N m 125 in lb Crankshaft End Play free 0 225 1 025 mm 0 0089 0...

Page 12: ...tire Crankshaft in V Blocks 0 10 mm 0 0039 in Crankshaft Eccentrics O D New 66 940 66 970 mm 2 6354 2 6366 in Max Wear Limit 66 89 mm 2 633 in Balance Weight Bearing Surface I D New 67 011 67 086 mm 2 6382 2 6412 in Max Wear Limit 67 140 mm 2 6430 in Balance Weight Screw Torque 10 0 N m 90 in lb Guide Pin O D New 11 950 11 975 mm 0 4705 0 4715 in Max Wear Limit 11 900 mm 0 4685 in Guide Shoe Width...

Page 13: ...Retaining Screw Torque 66 5 N m 588 in lb Governor Governor Cross Shaft to Crankcase Running Clearance 0 013 0 075 mm 0 0005 0 003 in Governor Cross Shaft O D New 5 975 6 012 mm 0 2352 0 2367 in Max Wear Limit 5 962 mm 0 2347 in Governor Gear Shaft to Governor Gear Running Clearance 0 09 0 16 mm 0 0035 0 0063 in Governor Gear Shaft O D New 5 99 6 00 mm 0 2358 0 2362 in Max Wear Limit 5 977 mm 0 02...

Page 14: ...End Gap New Bore Top Ring 0 15 0 40 mm 0 006 0 016 in Middle Ring 0 30 0 55 mm 0 012 0 022 in Used Bore max 0 77 mm 0 030 in Piston Thrust Face O D SV470 SV480 New 83 948 83 962 mm 3 3050 3 3056 in Max Wear Limit 83 828 mm 3 3003 in SV530 SV540 New 88 948 88 962 mm 3 5018 3 5024 in Max Wear Limit 88 828 mm 3 4972 in SV590 SV600 New 93 928 93 942 mm 3 6980 3 6985 in Max Wear Limit 93 828 mm 3 6940 ...

Page 15: ...imum Lift 8 9 mm 0 350 in Exhaust Valve Minimum Lift 8 9 mm 0 350 in Nominal Valve SeatAngle 45 Intake Valve Stem to Valve Guide Running Clearance 0 038 0 076 mm 0 0015 0 003 in Exhaust Valve Stem to Valve Guide Running Clearance 0 050 0 88 mm 0 0020 0 0035 in Intake Valve Guide I D New 6 038 6 058 mm 0 2377 0 2385 in Max Wear Limit 6 135 mm 0 2415 in Intake Valve Stem Diameter New 5 982 6 0 mm 0 ...

Page 16: ...7 47 5 35 82 7 61 116 6 86 139 7 103 61 0 45 M14 58 3 43 76 4 55 131 5 97 184 4 136 219 7 162 94 9 70 Noncritical Fasteners Into Aluminum Noncritical Fasteners Into Aluminum Tightening Torque N m in lb or 10 Property Class 4 8 5 8 8 8 10 9 12 9 4 8 5 8 8 8 10 9 12 9 N m in lb x 0 113 N m ft lb x 1 356 in lb N m x 8 85 ft lb N m x 0 737 Torque Conversions Oil Drain Plugs Tightening Torque N m Engli...

Page 17: ...1 14 Section 1 Safety and General Information ...

Page 18: ...ne 1 800 533 0492 International 1 507 455 7223 8 00 am 8 00 pm EST Fax 1 800 578 7375 1 586 578 7375 International 1 507 455 7063 Mail SPX Corp OTC 28635 Mound Rd Warren MI 48092 3499 Some of the specialty tools are shown and mentioned at various points in this manual A complete catalog of all available tools may be ordered under Kohler Part No TP 2546 The tool price list is available under Kohler...

Page 19: ...si Lock rod you will also need to remove the studs If it is a Command rod you will need to grind off the aligning steps so the joint surface is flat Find a 1 long capscrew with the correct thread size to match the threads in the connecting rod Obtain a flat washer with the correct I D to slip on the capscrew and an O D of approximately 1 Kohler Part No 12 468 05 S can be used if you don t have the...

Page 20: ...logged fuel line 4 Loose or faulty wires or connections 5 Faulty choke or throttle controls 6 Faulty spark plug 7 Low compression 8 Faulty ACR mechanism Engine Will Not Crank 1 PTO drive is engaged 2 Battery is discharged 3 Safety interlock switch is engaged 4 Loose or faulty wires or connections 5 Faulty key switch or ignition switch 6 Faulty electric starter 7 Seized internal engine components E...

Page 21: ...s dirty or clogged These could indicate improper maintenance Check the carburetor throat for dirt Dirt in the throat is further indication that the air cleaner was not functioning properly Check if the oil level is within the operating range on the dipstick If it is above sniff for gasoline odor Check the condition of the oil Drain the oil into a container it should flow freely Check for metal chi...

Page 22: ... the level in the open side If the level in the engine side is the same as the open side no vacuum or the level in the engine side is lower than the level in the open side pressure check for the conditions in the table below 4 Close the pinch clamp before stopping the engine To perform the test with the vacuum pressure gauge 1 Insert the stopper as in step 1 2 Insert the barbed gauge fitting into ...

Page 23: ...aft or insert a shoulder bolt through the slot and thread it into the mounting hole If the flywheel end is more accessible you can use a breaker bar and socket on the flywheel nut screw to hold it in position You may need an assistant to hold the breaker bar during testing If the engine is mounted in a piece of equipment you may be able to hold it by clamping or wedging a driven component Just be ...

Page 24: ...e or damaged air cleaner components could allow unfiltered air into the engine causing premature wear and failure Intake air is drawn in through the upper opening from the blower housing passes through the precleaner if so equipped the paper element and then into the carburetor The outer air cleaner cover is secured by two knobs and removed by turning the knobs counterclockwise Air Cleaner Cover K...

Page 25: ...ll the precleaner if so equipped into the upper section of the air cleaner cover Make sure the hole in the precleaner is aligned with the upper mounting knob See Figure 9 7 Reinstall the air cleaner cover and secure with the two knobs 8 When element replacement is necessary order Kohler Part No 20 083 02 S Inspect Air Cleaner Components Whenever the air cleaner cover is removed or the paper elemen...

Page 26: ...studs thread into the air cleaner base and they should only be removed if necessary Reassembly The following procedure is for complete assembly of all air cleaner components Steps 1 3 are necessary only if the air cleaner base and or the cover mounting studs were removed in Disassembly 1 Install the mounting studs into the air cleaner base if removed previously Tighten the studs until bottomed or ...

Page 27: ... or every 100 hours of operation more often under extremely dusty dirty conditions remove the blower housing and any other cooling shrouds Clean the cooling fins and external surfaces as necessary Make sure all parts are reinstalled Torque the M6 blower housing fasteners to 7 5 N m 65 in lb NOTE Operating the engine with a blocked grass screen dirty or plugged cooling fins and or cooling shrouds r...

Page 28: ...ch method it should be 90 octane minimum Unleaded gasoline is recommended as it leaves less combustion chamber deposits Leaded gasoline may be used in areas where unleaded is not available and exhaust emissions are not regulated Be aware however that the cylinder head will require more frequent service Gasoline Alcohol blends Gasohol up to 10 ethyl alcohol 90 unleaded gasoline by volume is approve...

Page 29: ...engines are equipped with an in line fuel filter Periodically inspect the filter and replace when dirty Replacement is recommended annually or every 100 hours Use a genuine Kohler filter Fuel Pump Some engines are equipped with an optional pulse fuel pump See Figure 5 1 Operation The fuel pump has two internal chambers separated by a diaphragm The air chamber is connected to the engine crankcase b...

Page 30: ...ons or faulty components Make sure the air cleaner base and carburetor are securely fastened to the engine using gaskets in good condition Make sure the air cleaner element is clean and all air cleaner components are fastened securely Make sure the ignition system governor system exhaust system and throttle and choke controls are operating properly If after checking the items listed above starting...

Page 31: ...fuel needle c Float level is set too high With fuel bowl removed and carburetor inverted the exposed surface of float must be parallel with the bowl gasket surface of the carburetor body d Dirt under fuel inlet needle Remove needle clean needle and seat and blow with compressed air e Bowl vent or air bleeds plugged Remove fuel bowl low idle fuel adjusting needle and welch plugs Clean vent ports an...

Page 32: ...ne and run at half throttle for 5 to 10 minutes to warm up The engine must be warm before doing steps 2 and 3 2 Low Idle Fuel Needle Setting Place the throttle into the idle or slow position Turn the low idle fuel adjustment needle out counterclockwise from the preliminary setting until engine speed decreases rich Note the position of the needle Now turn the adjusting needle in clockwise The engin...

Page 33: ...r to clean the idle ports and bowl vent thoroughly remove the welch plugs covering these areas Use SPX Tool No KO1018 and the following procedure to remove the welch plugs See Figure 5 6 1 Pierce the welch plug with the tip of the tool NOTE To prevent damage to the carburetor do not allow the tool to strike the carburetor body 2 Pry out the welch plug with the tip of the tool Throttle Lever and Sh...

Page 34: ...w Tip to Strike Carburetor Body Welch Plug Figure 5 7 Marking Choke Plate and Carburetor Body Figure 5 8 Removing Choke Plate 3 Remove the choke shaft and choke return spring Throttle Shaft Removal Do not attempt to remove the throttle shaft as repair kits are not available Throttle shaft wear is normally accompanied by corresponding wear to the carburetor body making it impractical to attempt a c...

Page 35: ...ition the choke plate as marked during disassembly Insert the choke plate into the slot in the choke shaft Make sure the choke shaft is locked between the tabs on the choke plate Throttle plate choke plate throttle shaft and choke shaft NOTE Do not submerge the carburetor in cleaner or solvent when plastic fiber rubber foam seals or gaskets are installed The cleaner may damage these components Ins...

Page 36: ...as the solenoid is removed Bench test the solenoid by grounding the solenoid case and applying 12 volt DC to the spade terminal If the plunger does not retract the solenoid is faulty and must be replaced Always use a new fuel bowl gasket whenever the solenoid is installed Refer to the wiring diagram in Section 7 and connect the fuel shut off solenoid Figure 5 11 Fuel Shut Off Solenoid High Altitud...

Page 37: ... the fast or high speed position The actuating tab of the choke lever should be just below the end of the choke adjusting screw See Figure 5 13 Figure 5 14 Typical Throttle Choke Controls 3 Align the hole in the throttle lever with the hole in the speed control bracket by inserting a pencil or 6 35 mm 1 4 in drill bit See Figure 5 15 Cold Engine Warm Engine Figure 5 15 Aligning Holes in Speed Cont...

Page 38: ...s Do not tamper with the governor setting Over speed is hazardous and could cause personal injury 1 Make sure the throttle cable is adjusted properly see Throttle Cable Adjustment 2 Start the engine and allow it to warm up Place the throttle control lever into the fast or high speed position Turn the choke adjustment screw See Figure 5 13 out conterclockwise so there is clearance from the choke le...

Page 39: ...ne control to ensure it stops against the stop screw which means it is properly set Choke Control Installation 1 Connect the choke cable boden wire to the engine choke control lever on the speed control bracket assembly 2 Position the choke cable under the cable clamp 3 Push move the choke control to the off position in the application panel until it bottoms then pull it back approximately 1 16 4 ...

Page 40: ... system is to maintain a desired idle speed regardless of ambient conditions temperature parasitic load etc that may change The system requires an additional procedure for setting the idle speed If speed adjustments are required proceed as follows 1 Make any necessary speed or control adjustments following the appropriate instructions already covered in this section 2 Move the throttle control to ...

Page 41: ...he engine speed and governor gear speed decreases the governor spring tension moves the governor arm to open the throttle plate wider This allows more fuel into the engine increasing engine speed This action takes place very rapidly so a reduction in speed is hardly noticed As the speed reaches the governed setting the governor spring tension and the force applied by the regulating pin will again ...

Page 42: ...peed occurs when a normal load is applied the governor should be set for greater sensitivity Governor Lever Hole No High Speed RPM 3201 3400 2 Throttle Lever Hole No X Governor Lever Green Spring X The desired high speed setting RPM will determine the governor spring position in the governor lever and the throttle lever as well as the spring used See Figure 5 23 Figure 5 23 Governor Spring Locatio...

Page 43: ...5 16 Section 5 Fuel System and Governor ...

Page 44: ...ommended can cause engine damage A logo or symbol on oil containers identifies the API service class and SAE viscosity grade See Figure 6 2 Figure 6 2 Oil Container Logo Check Oil Level The importance of checking and maintaining the proper oil level in the crankcase cannot be overemphasized Check oil BEFORE EACH USE as follows 1 Make sure the engine is stopped level and is cool so the oil has had ...

Page 45: ... bottom of the threads Allow a minute or two for the oil to be absorbed by the filter material 6 Put a drop of oil on your fingertip and wipe it on the rubber gasket Figure 6 3 Removing Dipstick Figure 6 4 Dipstick Seated 4 Remove the dipstick and check the oil level The oil level should be up to but not over the F mark on the dipstick See Figure 6 5 Operating Range NOTE To prevent extensive engin...

Page 46: ...nd axis shafts An integral pressure relief valve within the oil pump limits the maximum pressure of the system For a cold engine at start up the oil pressure can go up to 20 25 psi For a warm normal operating temperature engine at idle speed the oil pressure can go down to 5 psi Service The oil pump rotors typically require no servicing if normal maintenance is performed as outlined in Section 1 T...

Page 47: ... switch Testing the Oil Sentry Switch The Oil Sentry pressure monitor is a normally closed switch It is calibrated to open break contact with increasing pressure and close make contact with decreasing pressure within the range of 2 0 5 0 psi Compressed air a pressure regulator pressure gauge and a continuity tester are required to test the switch 1 Connect the continuity tester across the blade te...

Page 48: ...e gap or replace with a new plug as necessary Spark plug replacement is recommended at 500 hours 1 Before removing the spark plug clean the area around the base of the plug to keep dirt and debris out of the engine Due to the deep recess around the spark plug blowing out the cavity with compressed air is usually the most effective method for cleaning The spark plug is most accessible when the blow...

Page 49: ... screen clogged cooling fins and lean carburetion are some causes of overheating Carbon Fouled Soft sooty black deposits indicate incomplete combustion Incomplete combustion is usually caused by over rich carburetion weak ignition or poor compression Wet Fouled A wet plug is caused by excess fuel or oil in the combustion chamber Excess fuel could be caused by operating the engine with too much cho...

Page 50: ...ollowing components A magnet assembly which is permanently affixed to the flywheel Kill Switch or Off Position of Key Switch Air Gap 0 203 0 305 mm 0 008 0 012 in Flywheel Magnet Ignition Module Spark Plug Lamination A Kill Terminal B Spark Plug Terminal C Spark Plug Boot An electronic capacitive discharge ignition module which mounts on the engine crankcase A spark plug A kill switch or key switc...

Page 51: ...nition problems are most often due to poor or loose connections Before beginning the test procedure check all external wiring including ground leads for wiring harness and rectifier regulator if so equipped Be certain all ignition related wires are connected including the spark plug lead and all terminal connections fit snugly Make sure the ignition switch is in the run position NOTE The CD igniti...

Page 52: ... terminal C of high terminal lead With the ohmmeter leads connected in this manner the resistance of secondary should be 7 900 to 18 400 ohms NOTE This test cannot be performed unless module has been fired at least once 2 If plug is in good condition check adjust gap and reinstall 3 If visible and audible sparks are produced the ignition module is OK If visible and audible sparks are not produced ...

Page 53: ...e OFF If ON a spark will occur at the ground cable terminal which could cause an explosion if hydrogen gas or gasoline vapors are present Battery Maintenance Regular maintenance will ensure the battery will accept and hold a charge 1 Regularly check the level of electrolyte Add distilled water as necessary to maintain the recommended level NOTE Do not overfill the battery Poor performance or early...

Page 54: ...yTM Switch Indicator Light White Flywheel Ignition Module Spark Plug Red Green Stator Key Switch R A S M B Violet Optional Oil SentryTM Shutdown Optional Oil Sentry Switch Shutdown or Indicator Optional Fuel Solenoid Starter Solenoid Bendix Starter Engine Connector Recommended Fuse Rating 25 30 AMP Battery Regulator Rectifier AC AC B Figure 7 8 3 amp Unregulated Battery Charging System 70 Watt Lig...

Page 55: ... reversed some resistance should be measured about midscale on Rx1 range 3 If resistance is low in both directions the diode is shorted Replace the diode If resistance is high in both directions the diode or stator winding is open Use Test 4 4 Cut the sleeving on the charging lead to expose the diode connections Measure the resistance from the stator side of diode to ground using an ohmmeter 4 If ...

Page 56: ...en Use Test 4 4 If resistance is approximately 0 15 ohms stator winding is OK diode is open Replace diode If resistance is 0 ohms stator winding is shorted Replace stator If resistance is infinity ohms stator winding or lead is open Replace stator 1 Make sure lights are not burned out 2 Disconnect the lighting lead yellow from the wiring harness With engine running in the fast setting measure volt...

Page 57: ...sing an ohmmeter Test 3 3 With the engine stopped measure the resistance from braking lead to ground using an ohmmeter 3 If resistance is approximately 0 2 0 4 ohms stator is OK If resistance is 0 ohms stator is shorted Replace stator If resistance is infinity ohms stator or lighting lead is open Replace stator Problem Conclusion 1 Make sure lights are not burned out 2 Disconnect the braking lead ...

Page 58: ...tional Oil Sentry Indicator Light Battery Optional Fuse Green Optional Oil Sentry Switch Indicator Optional Oil Sentry Switch Shutdown Red Green Engine Connector B Rectifier Regulator AC AC Ignition Module Spark Plug Flywheel Figure 7 9 9 or 15 amp Regulated Battery Charging System Stator Optional Fuel Solenoid Bendix Starter Starter Solenoid ...

Page 59: ...nts Figure 7 10 9 or 15 amp Stator and Rectifier Regulator Figure 7 11 Proper Connection to Test 9 or 15 amp Charging System DC Volt Meter Battery Ammeter Flywheel Stator Rectifier Regulator AC B AC Rectifier Regulator AC B AC 9 or 15 Amp Stator ...

Page 60: ...ease when load is applied test stator Tests 2 and 3 2 Remove connector from rectifier regulator With engine running in the fast position measure AC voltage across stator leads using an AC voltmeter 2 If voltage is 28 volts or more stator is OK Rectifier regulator is probably faulty Verify with Rectifier regulator tester KO3221 If voltage is less than 28 volts stator is probably faulty and should b...

Page 61: ...pinion and flywheel ring gear may clash resulting in damage to the starter NOTE If the starter does not crank the engine shut off the starter immediately Do not make further attempts to start the engine until the condition is corrected NOTE Do not drop the starter or strike the starter frame or end cap Doing so can damage the starter Problem Starter Does Not Energize Starter Energizes But Turns Sl...

Page 62: ... removal tool around the armature shaft with the retaining ring in the inner groove see Figure 7 13 Slide the collar over the inner halves to hold them in position Figure 7 13 Assembling Inner Half of Tool Around The Armature Shaft and Retaining Ring 4 Thread the center screw into the removal tool until you feel resistance Use a wrench 1 1 8 or adjustable to hold the base of the removal tool Use a...

Page 63: ...stance is felt Figure 7 15 Assembling Larger Inner Half Around Spring Retainer 6 Hold the base of the tool with a 1 1 8 wrench and turn the center screw clockwise with a 1 2 or 13 mm wrench to draw the spring retainer up around the retaining ring Stop turning when the resistance increases Disassemble and remove the tool Starter Disassembly 1 Remove the drive components following the instructions f...

Page 64: ...d install the drive end cap onto the front of the frame 4 If the brush assembly is not being replaced position the springs and brushes within their pockets in the carrier move them to the retracted position and install carton staples to retain them See Figure 7 20 Replacement brushes come pre assembled in the carrier housing retained with two carton staples Figure 7 20 Brush Carrier Assembly with ...

Page 65: ... bolts 7 Install the thru bolts and hex nuts Torque to 3 3 3 9 N m 30 35 in lb See Figure 7 22 Figure 7 22 Torquing Thru Bolts 8 Install the insulating washer and hex flange nut onto the positive brush lead stud Make sure the stud is centered and does not touch the metal end cap Torque the hex flange nut to 2 2 4 5 N m 20 40 in lb NOTE After installation and connection of the starter lead torque t...

Page 66: ...these cleaners can quickly break down the lubricating properties of engine oil Typical Disassembly Sequence 1 Drain oil from the crankcase and remove oil filter 2 Remove blower housing 3 Disconnect spark plug lead 4 Remove muffler 5 Remove rectifier regulator 6 Remove electric starter 7 Remove air cleaner 8 Remove external governor components carburetor and fuel pump 9 Remove ignition module 10 Re...

Page 67: ...lug the connector from the rectifier regulator 2 Remove the two screws securing the rectifier regulator to the crankcase Remove the rectifier regulator See Figure 8 5 Figure 8 3 Removing Blower Housing Screws Disconnect Spark Plug Lead 1 Carefully pull on the boot section and disconnect the spark plug lead Figure 8 2 Removing Oil Sentry Switch Remove Blower Housing 1 Remove the four shoulder screw...

Page 68: ...r Components 3 Remove the two hex flange nuts or single nut and long mounting screw securing the air cleaner base See Figure 8 9 Figure 8 10 Removing Air Cleaner Base and Breather Hose Remove External Governor Components Carburetor and Fuel Pump WARNING Explosive Fuel Gasoline is extremely flammable and its vapors can explode if ignited Store gasoline only in approved containers in well ventilated...

Page 69: ...ead 3 If the carburetor uses a fuel solenoid carefully cut the plastic tie strap and disconnect the fuel solenoid lead from the wiring harness See Figure 8 14 Figure 8 15 Removing Carburetor Figure 8 12 Disconnecting Pulse Line from Fitting 2 Remove the heat deflector mounting screw and special washer which also secures the ground lead for the fuel shut off solenoid if so equipped See Figure 8 13 ...

Page 70: ...later Unhook the governor spring then remove the control bracket with fuel pump attached if equipped and linkages from the engine See Figures 8 16 and 8 17 Figure 8 18 Removing Governor Lever 7 Remove the carburetor gasket then carefully remove the heat deflector and gasket from the intake stud The heat deflector is made from a plastic that is quite brittle Do not pry on the corners or you risk cr...

Page 71: ...ng Hardware 3 Carefully lift the cooling fan to disengage the two drive pins and remove it from the flywheel 4 Remove the flywheel from the crankshaft using a puller See Figure 8 24 NOTE Always use a puller to remove the flywheel from the crankshaft Do not strike the crankshaft or flywheel as they could be cracked or damaged Figure 8 22 Removing Grass Screen NOTE Always use a flywheel strap wrench...

Page 72: ...e Figure 8 26 Figure 8 28 Loosening Adjustment Set Screw and Nut Figure 8 26 Removing Valve Cover Screws 2 Remove the valve cover and gasket from the cylinder head See Figure 8 27 Figure 8 24 Removing Flywheel Using Puller 5 Remove the flywheel key from the crankshaft Remove the Stator 1 Remove the two screws securing the stator to the closure plate bosses See Figure 8 25 NOTE To disconnect the B ...

Page 73: ...e the six hex flange screws securing the cylinder head Note the thick washer used on the screw closest to the exhaust port See Figure 8 29 Figure 8 30 Removing Cylinder Head and Gasket 6 Remove the drain back check ball from the keyhole slot in the crankcase See Figure 8 31 Figure 8 31 Removing Drain Back Check Ball from Crankcase Disassemble Cylinder Head NOTE Before disassembly mark all valve tr...

Page 74: ...Remove the compressor then remove the valve spring caps valve springs and valves Figure 8 35 Removing Closure Plate Screws 2 A gasket is used between the closure plate and crankcase If necessary carefully tap on the bosses for the starter or oil filter with a soft faced mallet to loosen Do not pry on the gasket surfaces of the crankcase or oil pan as this can cause damage resulting in leaks 3 Remo...

Page 75: ...red for closure plate disassembly and cleaning of the oil passages NOTE The ACR weight and spring normally captured by the thrust washer and installation of closure plate will fall out if the exhaust cam gear is turned upside down Figure 8 38 Removing Oil Passage Cover and Gasket Remove Cam Gears Cam Shafts and Oil Pump 1 Remove the thrust washers and cam gears from the cam shafts See Figure 8 39 ...

Page 76: ...he cam shaft See Figure 8 43 Figure 8 44 Removing Connecting Rod Cap 3 Carefully push the connecting rod and the piston away from the crankshaft and out of the cylinder bore See Figure 8 45 Figure 8 41 Removing Exhaust Side Cam Shaft and Slotted Thrust Washer 4 Remove the two screws securing the oil pump and intake side cam shaft to the crankcase Carefully pull upward on the cam shaft to remove th...

Page 77: ... Figure 8 46 Separating Piston from Connecting Rod Remove Piston Rings 1 Remove the top and center compression rings using a ring expander See Figure 8 47 2 Remove the oil control ring rails then remove the spacer Figure 8 45 Removing Piston and Connecting Rod Remove Piston from Connecting Rod 1 Remove the wrist pin retainer and wrist pin Separate the piston from the connecting rod See Figure 8 46...

Page 78: ...ew securing the two balance weight halves together on the crankshaft Hold the guide pin with a wrench if required See Figure 8 50 Remove Governor Cross Shaft 1 Remove the hitch pin and washer located on the outside of the governor cross shaft See Figure 8 52 Figure 8 52 Removing Hitch Pin and Washer 2 Slide the shaft inward and remove it through the inside of the crankcase Be careful not to lose t...

Page 79: ...8 14 Section 8 Disassembly Remove PTO and Flywheel Side Oil Seals 1 Use a seal puller to remove the PTO and flywheel side oil seals See Figure 8 54 Figure 8 54 Removing Seal with a Seal Puller ...

Page 80: ...e TP 2159 A and Engine Inspection Data Record TP 2435 are also available use these to record inspection results Automatic Compression Release ACR This engine is equipped with an Automatic Compression Release ACR mechanism The ACR lowers compression at cranking speeds to make starting easier Operation The ACR mechanism consists of an actuating spring and a pivoting flyweight control pin assembly lo...

Page 81: ...eded see Section 1 it will be necessary to replace the crankshaft Crankcase Inspection and Service Check all gasket surfaces to make sure they are free of gasket fragments and deep scratches or nicks Check the cylinder wall for scoring In severe cases unburned fuel can wash the necessary lubricating oil off the piston and cylinder wall The piston rings make metal to metal contact with the wall cau...

Page 82: ...er Use the following procedure to accurately measure the piston to bore clearance 1 Use a micrometer and measure the diameter of the piston perpendicular to the piston pin up 8 mm 0 314 in from the bottom of the piston skirt as indicated in Figure 9 3 3 When the bore is within 0 064 mm 0 0025 in of desired size remove the coarse stones and replace with burnishing stones Continue with the burnishin...

Page 83: ...ring Balance Weight Guide Shoe 2 Use an inside micrometer telescoping gauge or similar tool and measure the width of the guide channel in the closure plate See Figure 9 7 Record these dimensions Balance Weight to Eccentric Clearance Before the balance weight assembly is reassembled to the crankshaft the running clearance to the crankshaft eccentrics must be accurately checked Failure to maintain t...

Page 84: ...ns Figure 9 9 Measuring Guide Shoe Hole I D If any of the measurements taken are outside the maximum wear limits listed in Section 1 the affected component s must be replaced Flywheel Inspection Inspect the flywheel for cracks and check the keyway for wear or damage Replace the flywheel if cracked If the flywheel key is sheared or the keyway is damaged replace the crankshaft flywheel and key Inspe...

Page 85: ...75 mm 45 1 5 mm 5 982 6 000 mm Intake Exhaust C D D H G Exhaust Valve F Exhaust Insert Intake Insert G H Intake Valve A A B B A F E Figure 9 10 Valve Details E Cylinder Head and Valves Inspection and Service Carefully inspect the valve mechanism parts Inspect the valve springs and related hardware for excessive wear or distortion Check the valves and valve seats for evidence of deep pitting cracks...

Page 86: ...s Leakage A poor grind on a valve face or seat will allow leakage resulting in a valve burned on one side only Coking Coking is normal on intake valves and is not harmful If the seat is good the valve could be reused after cleaning Hard starting or loss of power accompanied by high fuel consumption may be symptoms of faulty valves Although these symptoms could also be attributed to worn rings remo...

Page 87: ...lve guides and clean or replace the valves depending on their condition Stem Corrosion Moisture in fuel or from condensation are the most common causes of valve stem corrosion Condensation occurs from improper preservation during storage and when engine is repeatedly stopped before it has a chance to reach normal operating temperatures Replace corroded valves Overheating An exhaust valve subject t...

Page 88: ...ve seat cut properly 44 5 as measured from centerline when cut 89 this would result in the desired 0 5 1 0 full cut interference angle where the maximum pressure occurs on the valve face and seat Figure 9 11 Typical Valve Seat Cutter Lapping Valves Reground or new valves must be lapped in to provide a good seal Use a hand valve grinder with suction cup for final lapping Lightly coat valve face wit...

Page 89: ...on or ignition of the fuel charge before the timed spark can cause damage similar to detonation Preignition damage is often more severe than detonation damage Preignition is caused by a hot spot in the combustion chamber from sources such as glowing carbon deposits blocked fins improperly seated valve or wrong spark plug See Figure 9 12 for some common types of piston and ring damage Replacement p...

Page 90: ...new compression top and middle rings on the piston check piston to ring side clearance The maximum recommended side clearance for each ring is 0 04 mm 0 0016 in If the side clearance is greater than specified a new piston must be used Refer to Figure 9 14 Top Compression Ring to Groove Side Clearance 0 04 mm 0 0016 in Middle Compression Ring to Groove Side Clearance 0 04 mm 0 0016 in Figure 9 14 M...

Page 91: ...and Reassembly Sections 8 and 10 for removal and reinstallation procedures Check the oil pump and gears for cracks damage wear and smooth rotation Replace the pump if any binding is noted or reuse is questionable in any way A pressure relief valve is built into the oil pump to limit maximum pressure It is not serviceable If a problem exists with the pressure relief valve the oil pump assembly shou...

Page 92: ...bly and regulating pin from the closure plate with two small screwdrivers 6 Locate the governor pin from flywheel side With a small punch drive the pin out of the closure plate This could also be done with a press DO NOT remove the governor pin with a vise grip or pliers you may damage the closure plate 7 Remove any old gasket material from the mating surfaces of the crankcase and closure plate Us...

Page 93: ...9 14 Section 9 Inspection and Reconditioning ...

Page 94: ...ll cam levers 9 Install exhaust cam shaft cam gear and ACR 10 Install intake cam gear 11 Install oil seal into closure plate flywheel side 12 Install closure plate gasket closure plate and wiring harness 13 Assemble cylinder head 14 Install cylinder head 15 Install rocker arms and push rods 16 Install valve cover 17 Install stator and wiring harness 18 Install flywheel and fan 19 Install electric ...

Page 95: ...e 10 4 Securing Governor Shaft Install Oil Pump Assembly and Intake Cam Shaft 1 If the oil pump assembly was removed from the intake cam shaft reassemble it onto the shaft The drive pin holes are machined to be a clearance slip fit on one side and a press fit on the other Support the cam shaft with the clearance holes up and install the shorter 2 5 mm 0 098 in diameter pin in the outer hole closes...

Page 96: ...d the crankshaft is cross drilled for lower bearing lubrication Both styles of outlet seals are shown in Figure 10 9 If a new seal was ordered make sure it is the right one for the engine Figure 10 9 Oil Pump Outlet Seals 5 Install the intake cam shaft down into the crankcase boss Seat the rubber oil pump outlet seal into the machined pocket If an open style outlet seal is used check to make sure ...

Page 97: ...ws Install Crankshaft and Balance Weight 1 Assemble the crankshaft balance weight if removed from the crankshaft a Lubricate the crankshaft eccentrics and the balance weight bearing surfaces with oil b Install the two balance weight halves onto the crankshaft eccentrics as marked or originally installed c Align the weights and install the balance weight screw through the mounting holes from the PT...

Page 98: ...and make certain it is seated down around the entire circumference Use a soft rubber grip hammer handle and tap the piston connecting rod into the bore See Figure 10 18 The first tap should be rather firm so the oil ring moves from the compressor into the bore in one smooth quick motion Otherwise the oil ring rails may spring out and jam between the ring compressor and the top of the bore Figure 1...

Page 99: ...als Install the rod cap 4 Install the hex flange screws and torque in 2 increments first to 5 5 N m 50 in lb finally to 11 5 N m 100 in lb See Figure 10 19 Figure 10 20 Installing Cam Levers Install the Exhaust Cam Shaft and Cam Gear 1 If the drive pins were removed from the exhaust cam shaft follow the same procedure used earlier for the intake cam shaft and reinstall them See Figure 10 21 Figure...

Page 100: ... the formed groove in the thrust washer Slide the washer onto the cam shaft so the short drive pin is seated in the groove The grease will hold the washer in position Pivot the exhaust cam lever toward the push rod bore then insert the cam shaft into the counterbore of the crankcase Make sure the pin stays in the groove of the thrust washer See Figure 10 22 Figure 10 25 Installing Exhaust Cam Gear...

Page 101: ...ke sure the sealing surfaces of crankcase and closure plate are clean dry and free of any nicks or burrs Install a new closure plate gasket onto the crankcase Important 2 Apply grease to the outside flat surfaces of the balance weight guide shoe Position the guide shoe so the solid end is toward the crankshaft See Figure 10 29 Make sure the guide shoe stays in this position during the next step 3 ...

Page 102: ... 30 If the wiring harness was separated from the closure plate route the harness through the clamps and the slot in the closure plate Close the clamps to retain the harness 5 Torque the closure plate fasteners to 24 5 N m 216 in lb using the sequence shown in Figure 10 31 Figure 10 30 Closure Plate Installed Figure 10 31 Closure Plate Fastener Torque Sequence Assemble Cylinder Head Prior to assemb...

Page 103: ...Drain Back Check Ball 4 Install a new cylinder head gasket See Figure 10 34 IMPORTANT 2 If the crankshaft has not been turned since the installation of the crank gear turn it one 1 complete revolution This will set the piston at top dead center TDC of the compression stroke for proper valve lash adjustment later 3 Install the drain back check ball into the keyhole slot in the top of the crankcase ...

Page 104: ... rocker arms are positioned and adjusted See Figure 10 38 Figure 10 38 Installing Push Rods and Rocker Arm Assemblies Figure 10 40 Locking Adjustment Nut Set Screw Install Valve Cover 1 Make sure the sealing surfaces of the valve cover and cylinder head are clean and free of any nicks or burrs 2 Install a new valve cover gasket followed by the valve cover Position any brackets that mount on the va...

Page 105: ...nstalling Stator Install Wiring Harness 1 Check that the locking tang on the terminal of the violet B wiring harness lead is angled upward Insert the terminal into the center location of the rectifier regulator plug connector until it locks into place If not already inserted the two AC leads from the stator go in the outer locations See Figure 10 43 Figure 10 43 Installing B Lead into Connector In...

Page 106: ...ked or damaged if the key is not properly installed NOTE Always use a flywheel strap wrench or flywheel holding tool to hold the flywheel when tightening the flywheel fastener Do not use any type of bar or wedge between the cooling fins or flywheel ring gear as these parts could become cracked or damaged 1 Install the woodruff key into the crankshaft keyway Make sure that the key is fully seated a...

Page 107: ...25 mm 0 010 in flat feeler gauge between the magnet and ignition module See Figure 10 49 Loosen the screws so the magnet pulls the module against the feeler gauge Figure 10 49 Setting Air Gap 4 Torque the two screws to 6 0 N m 55 in lb into new as cast holes or 4 0 N m 35 in lb into used holes 5 Rotate the flywheel back and forth checking for clearance between the magnet and ignition module Make s...

Page 108: ...park plug and torque it to 24 30 N m 18 22 ft lb See Figure 10 51 3 Install a new intake gasket onto the carburetor stud then install the heat deflector The curved section should be down toward the engine with the protruding point on the back inserted into the intake port Be sure the protruding point goes through the large hole in the gasket to keep it aligned See Figure 10 53 Figure 10 53 Install...

Page 109: ...ap 8 Connect the fuel line to the carburetor and secure with a hose clamp See Figure 10 58 Figure 10 58 Connecting Fuel Line to Carburetor 9 Install the air cleaner base a Install a new air cleaner base gasket Check that the two metal spacers are in the air cleaner base mounting holes and install the base onto the stud s and or alignment pin Make sure the upper mounting tab is positioned above the...

Page 110: ...sure Plate Figure 10 62 Torquing Air Cleaner Fasteners 10 Attach the breather hose to the valve cover and air cleaner base Install and Adjust Governor Lever 1 Install the governor lever onto the governor shaft with the lever section up Connect the throttle linkage using the black linkage bushing See Figure 10 63 NOTE It is recommended that a new governor lever be installed whenever removal is perf...

Page 111: ...to new as cast holes or 4 0 N m 35 in lb into used holes See Figure 10 67 Figure 10 64 Adjusting Governor and Linkage Mounting Speed Control Bracket 1 Attach the governor spring to the governor lever and the throttle lever of the speed control bracket in the original holes If the holes were not marked during disassembly refer to the chart in Section 5 Figure 5 23 Connect the choke linkage from the...

Page 112: ...e and route the spark plug lead through the underside slot See Figure 10 70 3 Connect the pulse and fuel lines to the fuel pump and secure with clamps See Figure 10 68 Figure 10 70 Installing Blower Housing 2 Check that the stator leads are within the notch of the blower housing Align the mounting locations then install the four M6 shouldered mounting screws If a flat washer was used under the hea...

Page 113: ...re 10 72 Installing Grass Screen Install Oil Sentry or Pipe Plug 1 Apply pipe sealant with Teflon Loctite No 59241 or equivalent to the threads of the 1 8 pipe plug or adapter Install and tighten into the port on the closure plate See Figure 10 73 Torque pipe plug to 4 5 5 0 N m 40 45 in lb If a switch was installed apply sealant to the threads of the Oil Sentry switch and install into the adapter...

Page 114: ...Torquing Exhaust Flange Nuts Install Drain Plug Oil Filter and Oil 1 Install the oil drain plug and torque to 14 N m 125 in lb 2 Place a new replacement filter in a shallow pan with the open end up Pour new oil of the proper type in through the threaded center hole Stop pouring when the oil reaches the bottom of the threads Allow a minute or two for the oil to be absorbed by the filter material 3 ...

Page 115: ...e Engine It is recommended that the engine be operated on a test stand or bench prior to installation in the piece of equipment 1 Set the engine up on a test stand Install an oil pressure gauge Start the engine and check to be certain that oil pressure 5 psi or more is present 2 Run the engine for 5 10 minutes between idle and mid range Adjust the throttle and choke controls and the high speed set...

Page 116: ...2004W27 114 03 04 26 ...

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