KYMCO Mongoose 50-2T Service Manual Download Page 114

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. CYLINDER HEAD/VALVES

(90cc/70cc/50cc-4T)

7-4

TROUBLESHOOTING

•

The poor cylinder head operation can be diagnosed by a compression test or by tracing engine
top-end noises.

Poor performance at idle speed

White smoke from exhaust muffler

•

Compression too low

•

Worn valve stem or valve guide

•

Damaged valve stem seal

Compression too low

•

Incorrect valve clearance adjustment

Abnormal noise

•

Burned or bend valves

•

Incorrect valve clearance adjustment

•

Incorrect valve timing

•

Sticking valve or broken valve spring

•

Broken valve spring

•

Damaged or worn camshaft

•

Poor valve and seat contact

•

Worn cam chain guide

•

Leaking cylinder head gasket

•

Worn camshaft and rocker arm

•

Warped or cracked cylinder head

•

Poorly installed spark plug

Compression too high

•

Excessive carbon build-up in combustion
chamber

Summary of Contents for Mongoose 50-2T

Page 1: ...By KWANG YANG Motor Co Ltd First Edition Dec 2006 All rights reserved Any reproduction or unauthorized use without the written permission of KWANG YANG Motor Co Ltd is expressly prohibited T100LA0975...

Page 2: ...sembly or system illustration and troubleshooting for the section The subsequent pages give detailed procedures for the section KWANG YANG MOTOR CO LTD OVERSEAS SALES DEPARTMENT OVERSEAS SERVICE SECTI...

Page 3: ...______ __________________________________________________________________________________ __________________________________________________________________________________ GENERAL INFORMATION _______...

Page 4: ...1 GENERAL INFORMATION 1 1 SERIAL NUMBER Location of Engine Serial Number 90cc 70cc 50cc 4T Location of Frame Serial Number Location of Engine Serial Number 50cc 2T...

Page 5: ...1 mm 0 004 in Idle speed 1800 rpm Lubrication type Forced pressure Wet sump Oil pump type Inner outer rotor type Oil filter type Full flow filtration Oil capacity 0 8 L 0 7 lmp qt 0 85 US qt Lubricat...

Page 6: ...4 mm 0 0016 in Idle speed 2000rpm Lubrication type Forced pressure Wet sump Oil pump type Inner outer rotor type Oil filter type Full flow filtration Oil capacity 0 8 L 0 7 lmp qt 0 85 US qt Lubricati...

Page 7: ...Idle speed rpm 2000rpm Lubrication type Forced pressure Wet sump Oil pump type Inner outer rotor type Oil filter type Full flow filtration Oil capacity 0 8 L 0 7 lmp qt 0 84US qt Lubrication System Oi...

Page 8: ...e Automatic controlled timing Exhaust Open 1mm Close Valve clearance Intake cold Exhaust Idle speed 2000 rpm Lubrication type Separate type Oil pump type Plunger type Oil filter type Full flow filtrat...

Page 9: ...ng bolts or nuts begin with larger diameter to smaller ones at several times and tighten to the specified torque diagonally Use genuine parts and lubricants When servicing the motorcycle be sure to us...

Page 10: ...ual working safety Disconnect the battery negative terminal before operation When using a spanner or other tools make sure not to damage the motorcycle surface After operation check all connecting poi...

Page 11: ...ed capacity After operation terminal caps shall be installed securely When taking out the connector the lock on the connector shall be released before operation Hold the connector body when connecting...

Page 12: ...rminal cover or loose negative terminal Check the double connector cover for proper coverage and installation Insert the terminal completely Check the terminal cover for proper coverage Do not make th...

Page 13: ...ure that it is not interfering with any moving or sliding parts When fixing the wire harnesses do not make it contact the parts which will generate high heat Route wire harnesses to avoid sharp edges...

Page 14: ...a sharp edge or corner When rubber protecting cover is used to protect the wire harnesses it shall be installed securely Do not break the sheath of wire If a wire or harness is with a broken sheath r...

Page 15: ...h adjacent or surrounding parts in all steering positions When a testing device is used make sure to understand the operating methods thoroughly and operate according to the operating instructions Be...

Page 16: ...e servicing methods and cautions included in this service manual Apply engine oil to the specified points Use designated engine oil for lubrication Apply grease for lubrication Transmission Gear Oil 9...

Page 17: ...lbf ft Remarks Stud bolt Oil filter screen cap L cover Cam shaft holder nut 90cc Cam shaft holder nut Tappet ADJ nut Pivot tensioner bolt Lifter tensioner bolt Lifter tensioner cap Mission case bolt M...

Page 18: ...ut Rear wheel hub nut Front shock absorber upper mount bolt Front shock absorber lower mount bolt Rear shock absorber upper mount bolt Rear shock absorber lower mount bolt Rear swing arm axle hub bolt...

Page 19: ...12 Long socket wrench A120E00015 Start clutch puller A120E00006 Flywheel puller A120E00001 Universal holder A120E00017 50cc 2T Tool Name Tool No Remarks Ref Page Flywheel puller A120E00001 Oil seal an...

Page 20: ...l seal Crankshaft one way clutch movable part Oil pump drive chain Balance gear A C generator Starter one way clutch Bearing movable part O ring face Oil seal lip Genuine KYMCO Engine Oil SAE15W 40 AP...

Page 21: ...eneral purpose grease for parts not listed Apply clean engine oil or grease to cables and movable parts not specified This will avoid abnormal noise and rise the durability of the ATV Throttle Cable S...

Page 22: ...1 GENERAL INFORMATION 1 19 Rear Axle Hub Collar Oil Seal Bearing Driven Sprocket Rear Swing Arm Axle...

Page 23: ...r Ignition Switch Coupler Harness Wire Ignition Coil Kill Switch Safety Front Brake Cable Front Stop Switch Wire Throttle Cable REG REC Wire Pilot Leads 50cc 2T Rear Stop Switch Wire Handlebar Switch...

Page 24: ...1 GENERAL INFORMATION 1 21 Oil Outlet Tube 50cc 2T Oil Level Switch Wire 50cc 2T A C G Wire Ignition Coil Ignition Coil Wire Starter Motor Wire...

Page 25: ...ON 1 22 Taillight Coupler Battery Positive Battery Negative Oil Pump Control Cable 50cc 2T Ignition Coil Wire Rear Brake Cable Fluid Hose Air Inlet Hose Throttle Cable Fuel Tube Autobystarter Wire Har...

Page 26: ...1 GENERAL INFORMATION 1 23 WIRING DIAGRAMS Mongoose 90 MXER 90R Mongoose 50 4T OFF ROAD G...

Page 27: ...1 GENERAL INFORMATION 1 24 MXER 90R ON ROAD...

Page 28: ...1 GENERAL INFORMATION 1 25 Mongoose 70...

Page 29: ...1 GENERAL INFORMATION 1 26 Mongoose 50 2T MXER 50R 2T OFF ROAD...

Page 30: ...1 GENERAL INFORMATION 1 27 MXER 50R 2T ON ROAD...

Page 31: ...ngs Leaking cylinder head gasket Air leaking through intake pipe Leaking intake manifold Incorrect ignition timing Incorrectly adjusted air screw Flooded carburetor Clogged air cleaner Throttle valve...

Page 32: ...ion chamber Poor quality fuel Clutch slipping Mixture too lean Ignition timing too early Start engine and accelerate lightly for observation Inspection Adjustment Symptom Probable Cause Engine speed i...

Page 33: ...ulty CDI unit Faulty A C generator Faulty ignition coil Broken or shorted spark plug wire Faulty ignition switch Remove spark plug and install it into spark plug cap to test spark by connecting it to...

Page 34: ...clog Cam timing gear aligning marks not aligned Faulty spring Inspection Adjustment Symptom Probable Cause Check ignition timing Check carburetor jets for clogging Check fuel pump for fuel supply Corr...

Page 35: ...rectifier coupler red wire and battery wire to engine ground and test voltage Inspection Adjustment Inspection Adjustment Symptom Symptom Probable Cause Probable Cause Normal voltage Battery has volta...

Page 36: ...aulty ignition coil Replace with a new spark plug and inspect again Check CDI unit coupler for looseness Inspection Adjustment Symptom Probable Cause Normal Abnormal Normal Abnormal Normal Abnormal Ab...

Page 37: ...__________________________________________________________ __________________________________________________________________________________ __________________________________________________________...

Page 38: ...2 FRAME COVERS EXHAUST MUFFLER 2 1...

Page 39: ...harnesses according to the Cable Harness Routing TORQUE VALUES Exhaust muffler lock bolt 35 N m 3 5 kgf m 25 lbf ft Exhaust muffler lock nut 90cc 70cc 50cc 2T 20 N m 2 kgf m 15 lbf ft Exhaust muffler...

Page 40: ...ever and pull up the seat at the rear To install the seat align the tabs on the seat with the grommets on the frame and press the seat down until it locks HANDLEBAR REMOVAL Remove handlebar cover See...

Page 41: ...two bolts and handlebar cover holder Remove the four bolts and upper handlebar holders Remove the handlebar INSTALLATION Reverse the HANDLEBAR REMOVAL procedures refer to the STEERING SYSTEM section i...

Page 42: ...two nuts attaching the front fender and rear fender at the right left side Remove the two bolts attaching front fender at the right left side Remover the fuel filler cap Remove the front fender and di...

Page 43: ...move the starter relay and CDI unit Remove the ten screws attaching the rear fender and foot boards at the right left side Remove the two screws attaching the rear fender at the rear Remove the three...

Page 44: ...ur bolts attaching the right left foot board FRONT CARRIER REMOVAL Remove the four bolts attaching front carrier at the right left side EXHAUST MUFFLER REMOVAL Remove the two nuts attaching the exhaus...

Page 45: ...sequence Torque Exhaust muffler lock bolt 35 N m 3 5 kgf m 25 lbf ft Exhaust muffler lock nut 90cc 70cc 50cc 2T 20 N m 2 kgf m 15 lbf ft Exhaust muffler lock nut 50cc 4T 10 N m 1 kgf m 7 lbf ft TAILL...

Page 46: ..._________________________________________________________________ SERVICE INFORMATION 3 1 MAINTENANCE SCHEDULE 3 3 FUEL LINE THROTTLE OPERATION 3 4 AIR CLEANER 3 5 SPARK PLUG CYLINDER COMPRESSION 3 7...

Page 47: ...gap 0 6 0 7 mm 0 024 0 028 in Spark plug Standard 90 cc NGK CR7HSA 70 cc NGK CR7HAS 50 cc 4T NGK CR7HAS 50 cc 2T NGK R8HAS Valve clearance 90 cc IN 0 1mm 0 004 in EX 0 1mm 0 004 in 70 cc IN 0 04mm 0 0...

Page 48: ...nt brake free play 10 20 mm 0 4 0 8 in Drive chain slack 10 20 mm 0 4 0 8 in TIRE PRESSURE 1 Rider Front 25 kPa 0 25 kgf cm 3 6 psi Rear 25 kPa 0 25 kgf cm 3 6 psi TIRE SIZE 90 cc Front 18 7 8 Rear 18...

Page 49: ...if necessary Carburetor Check idle speed starter operation Adjust if necessary Fuel line Check fuel hose for cracks or damage Replace if necessary Engine oil except 50cc 2T Replace Warm engine before...

Page 50: ...tle valve fully and check that the index mark on the pump body aligns with the aligning mark on the oil pump control lever Reference tip alignment within 1mm of index mark on open side is acceptable S...

Page 51: ...70cc 50cc 4T To replace the air cleaner 1 Remove the seat See page 2 3 2 Remove the five screws and then remove air filter case cover 3 Remove the air filter element and separate it from the box Scre...

Page 52: ...ment If foam air filter oil is not available motor oil may be used 5 Reinstall the element to the air filter case 6 Reinstall the element assembly and parts removed for access Apply the engine oil Squ...

Page 53: ...e throttle valve fully and push the starter button to test the compression Compression 90 cc 16 kgf cm 1600 kPa 227 2 psi 70 cc 14 kgf cm 1400kPa 198 8 psi 50 cc 4T 14 kgf cm 1400kPa 198 8 psi 50 cc 2...

Page 54: ...m 0 0016 in EX 0 04mm 0 0016 in Loosen the lock nut and adjust by turning the adjusting nut Special tool Tappet adjuster A120E00012 CARBURETOR IDLE SPEED Warm up the engine before this operation Start...

Page 55: ...several minutes and stop it Place a container under the engine Remove right side cover Remove the oil filler cap and drain plug to drain the oil Reinstall the drain plug and tighten the drain plug to...

Page 56: ...O ring oil strainer compression spring and drain plug Tighten the drain plug to specification Torque 15 N m 1 5 kgf m 11 lbf ft Oil Capacity At disassembly 0 8 L 0 7 lmp qt 0 85 US qt At change 0 7 L...

Page 57: ...ce a container under the engine Remove the oil filler bolt and drain plug to drain the oil Reinstall the drain plug and tighten to specification Torque 18 N m 1 8 kgf m 13 lbf ft Fill the engine with...

Page 58: ...ification BRAK SHOES The checking of brake shoes wear will disassemble the brake If the lining thickness below to the wear limit A 2 mm 0 08 in to replace the shoes as a set BRAKE PADS A wear indicato...

Page 59: ...n the lower lock nut Turn the lower adjusting bolt until specified free play is obtained Tighten the lower lock nut While applying the front brake turn out the upper adjusting bolt until the upper and...

Page 60: ...right until it stops completely then slightly move the handlebar from left to right Replace the tie rod ends if tie rod end has any vertical play Raise the front end of the machine so that there is n...

Page 61: ...tie rods ends This reference point will be needed during adjustment Loosen the lock nuts tie rod end of both tie rods The same number of turns should be given to both tie rods right and left until the...

Page 62: ...hub nut for looseness Check the rear wheel hub nut for looseness If the axle nuts are loose tighten them to the specified torque Torque Front 60 N m 6 kgf m 43 lbf ft Rear 70 N m 7 kgf m 50 lbf ft WH...

Page 63: ...chain slack A Adjust if out of specification Drive chain slack Approximately 10 20 mm 0 4 0 8 in Adjust drive chain slack Elevate the rear wheels by placing a suitable stand under the rear of frame L...

Page 64: ...ication The drive chain is equipped with rubber O rings between the chain plates Steam cleaning high pressure washes and certain solvents can damage these O rings Use only kerosene to clean the drive...

Page 65: ...lever SUSPENSION LUBRICATION Inject grease into the nipples using a grease gun until slight over flow is observed from the thrust covers Front Swing Arm Nipple Damaged cable sheath may cause corrosio...

Page 66: ...er free play at 10 20 mm 0 4 0 8 in 2 Loosen the locknuts R L front lower brake cables 3 Turn the adjusting bolts until the front lower brake cables is tensed 4 Apply the front brake lever and check f...

Page 67: ...edal cable 8 Turn the adjusting bolt until the specified free play is obtained 9 Tighten the locknut Brake pedal cable BRAKE FLUID Check if the fluid level is below the lower level mark through the in...

Page 68: ...__________________________________________________ __________________________________________________________________________________ LUBRICATION SYSTEM _______________________________________________...

Page 69: ...4 LUBRICATION SYSTEM 4 1 LUBRICATION SYSTEM 90cc 70cc 50cc 4T Oil Pump Oil Filter Screen Crankshaft Rocker Arm Shaft...

Page 70: ...4 LUBRICATION SYSTEM 4 2 LUBRICATION SYSTEM 50cc 2T...

Page 71: ...when it reaches its service limit After the oil pump is installed check each part for oil leaks SPECIFICATIONS mm in Item Standard Service Limit Inner rotor to outer rotor clearance 0 15 0 006 0 2 0 0...

Page 72: ...TIONS Recommended Motor Oil SAE20W20 2 stroke Motor Oil Oil Capacity 1 liter 0 88 lmp qt 1 06 US qt Light comes on 0 25 liter 0 22 lmp qt 0 265 US qt TROUBLESHOOTING Excessive white smoke or carbon de...

Page 73: ...filter cleaning OIL PUMP 90cc REMOVAL Place a container under the engine Remove the drain plug to drain the oil 3 9 Remove the A C generator flywheel 14 8 Remove the A C generator stator and pulsar co...

Page 74: ...r Rotor Oil Pump Body Screws Remove the two oil pump mounting bolts and the oil pump DISASSEMBLY Remove the screw and disassemble the oil pump INSPECTION Measure the pump body to outer rotor clearance...

Page 75: ...0 008 in Measure the rotor end to pump body clearance Service Limit 0 12 mm 0 0048 in ASSEMBLY Install the outer rotor inner rotor and pump shaft into the pump body Install the dowel pin Install the...

Page 76: ...over Make sure that the pump shaft rotates freely without binding INSTALLATION Reverse the OIL PUMP REMOVAL procedures Make sure that the pump shaft rotates freely without binding Install the oil pump...

Page 77: ...the drain plug to drain the oil page 3 9 Remove the A C generator flywheel page 14 8 Remove the A C generator stator and pulsar coil page 14 8 Remove the eight right crankcase cover bolts and the rig...

Page 78: ...4 LUBRICATION SYSTEM 4 10 Remove three oil pump mounting bolts and the oil pump Remove O rings and dowel pin Bolts Oil Pump O rings Dowel Pin...

Page 79: ...Body Outer Rotor Inner Rotor DISASSEMBLY Remove the screws and disassemble the oil pump INSPECTION Measure the pump body to outer rotor clearance Service Limit 0 25 mm 0 01 in Measure the inner rotor...

Page 80: ...e outer rotor inner rotor and pump shaft into the pump body Install the dowel pin Install the pump cover by aligning the hole in the cover with the dowel pin Tighten the screw to secure the pump cover...

Page 81: ...and dowel pin Install the oil pump and tighten the bolts Make sure that the pump shaft rotates freely without binding Install the oil pump gear and tighten the nut Inspect the O rings and replace if...

Page 82: ...4 LUBRICATION SYSTEM 4 14 Install the right crankcase cover and tighten the bolts Bolts Right Crankcase Cover...

Page 83: ...t of the tube by filling it with oil 2 Start the engine and allow it to idle with the oil control lever in the fully open position Visually check the oil flow 3 If there is no oil flowing out within 1...

Page 84: ...et tube Drain the oil inside the oil tank into a clean container Remove the oil tank The installation sequence is the reverse of removal Connect the oil tube properly Bleed air from the oil pump after...

Page 85: ...ting surface Damage to pump body Control lever operation Oil leaks through oil seals Worn or damaged pump pinion Do not allow foreign matters to enter the crankcase Before removing the oil pump clean...

Page 86: ...tall the oil filter in the reverse order of removal and fill the oil tank with specified oil up to the proper level Bleed air from the oil pump and oil lines Lubricate the O ring with grease or engine...

Page 87: ..._____________ __________________________________________________________________________________ __________________________________________________________________________________ FUEL SYSTEM ________...

Page 88: ...5 FUEL SYSTEM 5 1...

Page 89: ...hragm must be removed first to avoid damage Then clean with compressed air When the machine is not used for over one month drain the residual gasoline from the float chamber to avoid erratic idling an...

Page 90: ...eration Float level too low Intake air leak Engine idles roughly stalls or runs poorly Clogged fuel tank cap breather hole Faulty auto bystarter Bent kinked or restricted fuel line Ignition malfunctio...

Page 91: ...fuel tank INSTALLATION Reverse the FUEL TANK REMOVAL procedures FUEL VALVE REMOVAL Remove the screw and then remove control switch Disconnect all fuel tubes and then remove fuel valve Warning Fuel Ta...

Page 92: ...s if they are damaged or deteriorated Replace the O rings with new ones if they are damaged or deteriorated ASSEMBLY Reverse the DISASSEMBLY procedures Install rubber gasket control shaft washer and r...

Page 93: ...5 FUEL SYSTEM 5 6 INSTALLATION Reverse the FUEL VALVE REMOVEAL procedures Connect all fuel tube Reserve Fuel Tube Main Fuel Tube Outlet Fuel Tube...

Page 94: ...tank Refer to FUEL TANK section in the chapter 5 Remove the carburetor cap Pull out the throttle valve Compress the spring to disconnect the throttle cable by hand Remove the spring from the throttle...

Page 95: ...lve and jet needle for wear or damage ASSEMBLY Reverse the DISASSEMBLY procedures Install the throttle valve into the carburetor body Throttle Valve Needle Retainer Jet Needle Align the groove in the...

Page 96: ...ve front fender See page 2 5 Disconnect the oil recycle tube from cylinder head and frame Remove the bolt at the air cleaner left side Loosen the screw at the band and remove bolt at the air cleaner r...

Page 97: ...AL Remove front fender See page 2 5 Disconnect the air inlet hose from the frame Remove the bolt at the air cleaner left side Loosen the screw at the band and remove bolt at the air cleaner right side...

Page 98: ...carburetor then remove carburetor and insulator INSTALLATION Reverse the REMOVAL procedures Check the carburetor insulator and O rings for wear or damage Fuel Drain Plug Keep sparks and flames away f...

Page 99: ...move the float chamber Pull out the float pin then remove float and float valve Remove the main jet needle jet holder and needle jet Remove the slow jet Remove the air screw and throttle stop screw Au...

Page 100: ...o not force the screw against its seat to avoid seat damage Be sure to install the O ring in the reverse order of removal Needle Jet Throttle Stop Screw Spring Air Screw Spring Washer O ring Main Jet...

Page 101: ...IR O RING CHECK Remove the O ring Inspect the check the O ring for damage Replace with new ones if necessary FLOAT LEVEL INSPECTION Turn the carburetor upside down so that the float will go down to ma...

Page 102: ...ct a hose to the fuel enriching circuit and blow the hose with mouth If air cannot be blown into the hose clogged the auto bystarter is faulty Replace it with a new one Connect the auto bystarter yell...

Page 103: ...amage or clearance between the seat and reed Replace the valve if necessary INSTALLATION Install the reed valve in the reverse order of removal Do not disassemble or bend the reed stopper To do so can...

Page 104: ...__________________________________________________________ __________________________________________________________________________________ __________________________________________________________...

Page 105: ...or other adjustable support is required to support and maneuver the engine Be careful not to damage the machine body cables and wires during engine removal Use shop towels to protect the machine body...

Page 106: ...her Remove the spark plug cap Disconnect the A C generator and starter motor couplers Remove the front two mounting bolts and two nuts at the engine right left side Remove the four bolts and then remo...

Page 107: ...assembly to the left side of the machine INSTALLATION Reverse the REMOVAL procedures TORQUE VALUES Engine bracket bolt 27 N m 2 7 kgf m 19 lbf ft Front engine mounting bolt 45 N m 4 5 kgf m 32 lbf ft...

Page 108: ...or couplers Remove the spark plug cap Remove the two bolts on the drive sprocket Remove the drive sprocket and washer Remove the front two mounting bolts and two nuts at the engine right left side Rem...

Page 109: ...assembly to the left side of the machine INSTALLATION Reverse the REMOVAL procedures TORQUE VALUES Engine bracket bolt 27 N m 2 7 kgf m 19 lbf ft Front engine mounting bolt 45 N m 4 5 kgf m 32 lbf ft...

Page 110: ...______________________________________________________ __________________________________________________________________________________ ______________________________________________________________...

Page 111: ...7 CYLINDER HEAD VALVES 90cc 70cc 50cc 4T 7 1...

Page 112: ...warpage 0 05 0 002 IN 26 4881 1 029524 26 33 1 0532 Camshaft cam height EX 25 8073 1 032292 25 65 1 026 Valve rocker arm to shaft clearance 0 034 0 09 0 00136 0 0036 0 1 0 004 Valve stem to guide IN...

Page 113: ...stem to guide IN 0 01 0 037 0 0004 0 00148 0 06 0 0024 clearance EX 0 025 0 052 0 001 0 00208 0 08 0 0032 Valve spring free length 35 25 1 41 34 1 36 Valve spring compressed force 19 2 22 kg at 19 65...

Page 114: ...d valve stem seal Compression too low Incorrect valve clearance adjustment Abnormal noise Burned or bend valves Incorrect valve clearance adjustment Incorrect valve timing Sticking valve or broken val...

Page 115: ...10 N m 1 kgf m 7 lbf ft CAMSHAFT CAMSHAFT HOLDER REMOVAL Remove the cylinder head cover Refer to the CYLINDER HEAD COVER REMOVAL Remove the cam chain tensioner cap bolt and the O ring Turn the cam ch...

Page 116: ...l pins Remove the camshaft gear from the cam chain and remove the camshaft CAMSHAFT HOLDER DISASSEMBLY Take out the valve rocker arm shafts using a 5mm bolt Remove the valve rocker arms and arm shafts...

Page 117: ...e rocker arm bore cam lobe contact surface and adjuster surface for wear pitting scratches blue discoloration If any defects are found replace the rocker arm shaft with a new one then inspect lubricat...

Page 118: ...cessive play Inspect camshaft lobes for pitting scratches blue discoloration Measure the cam lobe height Service Limits 90cc IN 26 33mm 1 0532 in EX 25 65 mm 1 026 in 70cc IN 25 65 mm 1 026 in EX 25 5...

Page 119: ...e chapter 3 Install the camshaft dowel pins and holder Torque Cam shaft hold nut 90cc 20 N m 2 kgf m 14 lbf ft Apply engine oil to threads 70cc 50cc 4T 14 N m 1 4 kgf m 10 lbf ft Apply engine oil to t...

Page 120: ...REMOVE section in the chapter 5 Remove the exhaust muffler Refer to the EXHAUST MUFFLER REMOVE section in the chapter 2 Remove the two nuts and then remove the carburetor intake manifold Remove the co...

Page 121: ...ubtract each valve stem O D from the corresponding guide I D to obtain the stem to guide clearance Service limits IN 0 06 mm 0 0024 in EX 0 08 mm 0 0032 in CYLINDER HEAD INPECTION Check the spark plug...

Page 122: ...28 4 mm 1 136 in Outer 32 mm 1 28 in 50cc 4T 34 mm 1 36 in Measure compressed force valve spring and installed length Replace if out of specification Service limits 90cc IN 3 47 4 27 kg at 26 mm 1 04...

Page 123: ...Valve Spring Compressor A120E00040 Tap the valve stems gently with a plastic hammer for 2 3 times to firmly seat the cotters INSTALLATION Install the dowel pins and a new cylinder head gasket Reverse...

Page 124: ...__________________ __________________________________________________________________________________ __________________________________________________________________________________ CYLINDER PISTON...

Page 125: ...8 CYLINDER PISTON 8 1 90cc 70cc 50cc 4T...

Page 126: ...8 CYLINDER PISTON 8 2 50cc 2T...

Page 127: ...page 0 05 0 002 Cylindricity 0 05 0 002 Cylinder True roundness 0 05 0 002 Ring to groove Top 0 015 0 055 0 0006 0 022 0 09 0 0036 clearance Second 0 015 0 055 0 0006 0 022 0 09 0 0036 Top 0 15 0 3 0...

Page 128: ...ck or broken Compression too low or uneven compression Excessive smoke from exhaust muffler Worn stuck or broken piston rings Worn or damaged piston rings Worn or damaged cylinder and piston Worn or d...

Page 129: ...4 Piston pin hole I D 12 002 12 008 0 48008 0 48032 12 03 0 4812 Piston pin O D 11 994 12 0 47976 0 48 11 98 0 4792 Piston to piston pin clearance 0 002 0 014 0 00008 0 00056 0 03 0 0012 Piston ring e...

Page 130: ...cylinder gasket and dowel pins Clean any gasket material from the cylinder surface Remove the piston pin clip Press the piston pin out of the piston and remove the piston Dowel Pins Gasket Cam Chain...

Page 131: ...e piston and measure the piston ring to groove clearance Service Limits Top 0 09 mm 0 0036 in 2nd 0 09 mm 0 0036 in Remove the piston rings and insert each piston ring into the cylinder bottom Measure...

Page 132: ...bottom at 90 to the piston pin in both X and Y directions Cylinder I D Service Limit 90cc 70cc 47 1 mm 1 884 in 50cc 4T 39 1 mm 1 564 in Measure the cylinder to piston clearance Service Limit 0 1 mm...

Page 133: ...connecting rod to piston pin clearance Service Limit 0 06 mm 0 0024 in Inspect the exhaust side and intake side chain guides Wear Damage Replace Second Side Rail Top Side Rail Oil Ring Be careful not...

Page 134: ...rings with clean engine oil Carefully lower the cylinder over the piston by compressing the piston rings Apply proper clean engine oil around cylinder wall Be careful not to damage or break the piston...

Page 135: ...the fan cover Remove the bolt attaching the engine hood to remove the engine hood The installation sequence is the reverse of removal Remove the spark plug Remove the cylinder head bolts and the cylin...

Page 136: ...h a straight edge and feeler gauge Service Limit 0 10mm replace if over CYLINDER HEAD INSTALLATION Install the cylinder head on the cylinder properly Install a new cylinder head gasket onto the cylind...

Page 137: ...es Torque 10 N m 1 kgf m 7 lbf ft Install the spark plug Torque 15 N m 1 5 kgf m 11 lbf ft Install the engine hood and fan cover Perform the following inspections after installation Compression test A...

Page 138: ...emove the piston pin and piston Spread each piston ring and remove by lifting it up at a point just opposite the gap Remove the expander Piston Pin Clip Piston Piston Pin Cylinder Do not damage or scr...

Page 139: ...rea Measure the cylinder bore at three levels of A B and C in both X and Y directions Avoid the port area Take the maximum figure measured to determine the cylinder bore Service Limit 39 05 mm 1 562 i...

Page 140: ...vice Limit 0 1 mm 0 004 in Measure the piston pin hole I D Service Limit 12 03 mm 0 4812 in Measure the piston pin O D Service Limit 11 98 mm 0 4792 in Measure the piston to piston pin clearance Servi...

Page 141: ...ATION First install the expander in the second ring groove Then install the top and second rings in their respective ring grooves The piston rings should be pressed into the grooves with even force Af...

Page 142: ...end gaps are aligned with the piston ring pins in the ring grooves Lubricate the cylinder inside and piston rings with engine oil and install the piston into the cylinder while compressing the piston...

Page 143: ...9 DRIVE AND DRIVEN PULLEYS 9 0 9 DRIVE AND DRIVEN PULLEYS SERVICE INFORMATION 9 2 LEFT CRANKCASE COVER KICK STARTER 9 4 DRIVE PULLEY 9 7 CLUTCH DRIVEN PULLEY 9 9 9...

Page 144: ...9 DRIVE AND DRIVEN PULLEYS 9 1...

Page 145: ...74 0 7984 0 79896 19 94 0 7976 50cc 4T 19 96 19 974 0 7984 0 79896 19 94 0 7976 Drive face collar O D 50cc 2T 20 01 20 025 0 8004 0 801 19 98 0 7992 90cc 17 5 0 7 16 5 0 66 70cc 17 8 0 71 16 5 0 66 50...

Page 146: ...lder A120E00017 Clutch spring compressor A120E00034 Bearing puller A120E00037 Oil seal and bearing install A120E00014 TROUBLESHOOTING Engine starts but motorcycle won t move Lack of power Worn drive b...

Page 147: ...r spindle Remove three bolts at the kick starter spindle cover then remove kick starter spindle cover Gently turn the kick starter spindle to remove the starter driven gear together with the friction...

Page 148: ...ng for wear or damage Inspect the kick starter spindle and starter driven gear forcing parts for wear or damage ASSEMBLY Install the kick starter spindle bushing and return spring onto the left crankc...

Page 149: ...install the washer and then install the circlip Install the kick lever LEFT CRANKCASE COVER INSTALLATION First install the dowel pins Install the gasket Install the left crankcase cover and tighten th...

Page 150: ...pulley using a universal holder and remove the drive face nut and washer Remove the drive pulley Special tool Universal Holder A120E00017 Remove the movable drive face assembly and drive pulley colla...

Page 151: ...y collar for wear or damage Measure the O D of the drive pulley collar sliding surface Service Limit 90cc 23 94 mm 0 9576 in 70cc 50cc 4T 19 94 mm 0 7976 in 50cc 2T 19 98 mm 0 7992 in INSTALLATION Ins...

Page 152: ...Universal Holder A120E00017 Remove the clutch driven pulley and drive belt DRIVE BELT INSPECTION Check the drive belt for cracks separation or abnormal or excessive wear Measure the drive belt width...

Page 153: ...remove the clutch drive plate nut Loosen the clutch spring compressor and disassemble the clutch driven pulley assembly Remove the seal collar Pull out the three guide roller pins and guide rollers Re...

Page 154: ...cc 2 mm 0 08 in 50cc 1 mm 0 04 in INSPECTION Measure the driven face spring free length Service Limit 90cc 137 5 mm 5 5 in 70cc 92 mm 3 68 in 50cc 4T 90 mm 3 6 in 50cc 2T 92 8 mm 3 712 in Check the dr...

Page 155: ...grease to the outer bearing Drive a new outer bearing into the driven face with the sealed end facing up Seat the snap ring in its groove Apply grease to the driven face bore areas Press a new needle...

Page 156: ...9 DRIVE AND DRIVEN PULLEYS 9 13 CLUTCH DISASSEMBLY Remove the circlips to disassemble the clutch CLUTCH DRIVEN PULLEY ASSEMBLY Circlip Clutch Lining Keep grease off the clutch linings...

Page 157: ...en face Install the seal collar Remove any excessive grease Set the driven pulley assembly collar OFF ROAD driven face spring and clutch assembly onto the clutch spring compressor Compress the clutch...

Page 158: ...tch driven pulley and driven belt onto the drive shaft Install the clutch outer Hold the clutch outer with the universal holder Install and tighten the clutch outer nut Torque 40 N m 4 kgf m 29 lbf ft...

Page 159: ..._____________________________________________________________________________ __________________________________________________________________________________ _______________________________________...

Page 160: ...10 FINAL REDUCTION TRANSMISSION SYSTEM 10 1...

Page 161: ...o hold the bearing inner race for this operation SPECIFICATIONS Specified Oil GEAR OIL SAE 90 Oil Capacity At change 0 11 liter 0 1 lmp qt 0 12 US qt At disassembly 0 12 liter 0 11 lmp qt 0 13 US qt T...

Page 162: ...case cover or the bearings turn roughly If any defects are found replace the bearing with a new one Inspect the final shaft bearing oil seal for wear or damage Remove the final gear and countershaft...

Page 163: ...AXLE REMOVAL Remove the clutch friven pulley Refer to chapter 9 Remove the primary drive axle Inspect the final gear teeth Blue discoloration pitting wear Replace Inspect the countershaft gear teeth B...

Page 164: ...final shaft into left crankcase Install the countershaft and washer into the left crankcase Install the resin washer onto countershaft Install the dowel pins and a new gasket onto the right crankcase...

Page 165: ...e with oil and install the oil filler bolt Refer to the TRANSMISSION OIL REPLACEMENT section in the chapter 3 Specified Gear Oil KYMCO SIGMA GEAR OIL 90 Oil Capacity At change 0 11 liter 0 1 lmp qt 0...

Page 166: ...____________________________________________________ __________________________________________________________________________________ ________________________________________________________________...

Page 167: ...11 CRANKCASE CRANKSHAFT 11 1 90cc 70cc 50cc 4T...

Page 168: ...11 CRANKSCASE CRANKSHAFT 11 2 50cc 2T...

Page 169: ...024 Connecting rod big end radial clearance 0 0 008 0 0 00032 0 05 0 002 Run out 0 1 0 004 SPECIFICATIONS 50cc 2T mm in Item Crankshaft Standard Service Limit Connecting rod big end side clearance 0 6...

Page 170: ...Remove the crankshaft from the left crankcase Remove the cam chain Remove the gasket and dowel pins Clean off all gasket material from the crankcase mating surfaces Bolt Crankshaft Do not damage the c...

Page 171: ...out B Service Limit 0 1 mm 0 004 in Measure the connecting rod big end side clearance C Service Limit 0 05 mm 0 002 in Measure the crank width D Out of specification 90cc 45 15 45 2 mm 1 806 1 808 in...

Page 172: ...ns and a new gasket onto the left crankcase Install the crankshaft into the left crankcase Install the right crankcase Tighten the crankcase attaching bolt Torque 10 N m 1 kgf m 7 lbf ft Place the rig...

Page 173: ...crankcase Special tool Crankcase puller A120E00026 CRANKSHAFT REMOVAL Attach the crankcase puller on the left crankcase and remove the crankshaft from the left crankcase Special tool Crankcase puller...

Page 174: ...g puller Special tool Universal bearing puller A120E00030 CRANKSHAFT INSPECTION Measure the connecting rod big end side clearance Service Limit 0 6 mm 0 024 in Measure the connecting rod big end radia...

Page 175: ...ay The bearings must be replaced if they are noisy or have excessive play CRANKSHAFT INSTALLATION Wash the crankshaft in cleaning solvent and then check for cracks or other faults Axial Play Play Radi...

Page 176: ...Special tool Oil seal and bearing install A120E00014 Install the crankshaft into the left crankcase Special tool Crankshaft install tool A120E00016 Oil Seal And Bearing Install Crankcase Install Tool...

Page 177: ...urface Assemble the crankcase halves Special tool Crankshaft crankcase install tool A120E00024 The distance between the right crankcase oil seal and crankcase surface is about 12 5 0 5 mm 0 5 0 0 02 i...

Page 178: ...T 11 12 The distance between the left crankcase oil seal and crankcase surface is about 1 mm 0 04 in Install and tighten the crankcase attaching bolts Oil Seal 1 0mm After assembly check the crankshaf...

Page 179: ...____________________________________________ __________________________________________________________________________________ ________________________________________________________________________...

Page 180: ...12 FRONT WHEEL FRONT BRAKE FRONT SUSPENSION STEERING SYSTEM 12 1...

Page 181: ...S mm in Item Standard Service Limit Radial 2 0 08 Front wheel rim run out Axial 2 0 08 Front brake drum I D 85 85 5 3 4 3 42 84 3 36 Front brake lining thickness 4 0 16 2 0 08 Tie rod length 254 5 255...

Page 182: ...rs to one side or does not track straight Improperly tightened axle nut Uneven front shock absorbers Soft front shock absorber Bent front arm Weak shock springs Bent steering knuckle Insufficient damp...

Page 183: ...g the wheel panel and front wheel Elevate the front wheels by placing a suitable stand under the frame Remove the nut cover Remove the cotter pin Remove nut attaching the wheel hub and washer Remove t...

Page 184: ...ect the front wheel hub Replace it if cracks or damage Inspect the front brake drum Measure the front brake drum I D Service limits 84 mm 3 36 in Turn the inner race of each bearing with your finger t...

Page 185: ...SION STEERING SYSTEM 12 6 FRONT WHEEL HUB DISASSEMBLY Remove the side collar Remove the dust seal of each side Remove the front wheel hub bearings and distance collar Side Collar Dust Seal Wheel Beari...

Page 186: ...and oil seal lips of the wheel hub Install wheel hub side collar washer and tight the nut wheel hub Torque 60 N m 6 kgf m 43 lbf ft Install cotter pins and nut cover Install the front wheel and tight...

Page 187: ...connect the front brake cable from brake cam lever and remove the brake shoe plate INSPECTION Measure the front brake lining thickness A Service limit 2 mm 0 08 in DISASSEMBLY Remove return ring Remov...

Page 188: ...stall front wheel See page 12 7 Adjust the front brake cable free play Refer to the BRAKE LEVER FREE PLAY section in the CHAPTER 3 Brake cable free play 10 20 mm 0 4 0 8 in Make sure that the boss on...

Page 189: ...ter pin and nut attaching the front arm and steering knuckle Remove steering knuckle INSPECTION Inspect the shock absorber rod Replace the shock absorber assembly if bends or damage Inspect the shock...

Page 190: ...m 4 5 kgf m 32 lbf ft Check the dust seal If wear or damage replace the dust seal Check the front arm side play by moving it from side to side If side play noticeable replace the bushings Check the fr...

Page 191: ...he steering knuckle into the front arm and tighten the knuckle arm nut Torque 50 N m 5 kgf m 36 lbf ft Install the cotter pin and band ends of cotter pin Install the tie rod into the steering knuckle...

Page 192: ...INSTALLATION Install handlebar and handlebar holder then tighten the four bolts Torque 14 N m 1 4 kgf m 10 lbf ft Refer to the BRAKE FREE PLAY section in the CHAPTER 3 to adjust front brake Brake cabl...

Page 193: ...mn and collar Remove the two bolts to remove the steering bracket and rubber collar Remove steering column and collar INSPECTION Inspect the steering column Replace it if bends or damage Inspect the c...

Page 194: ...snap ring Apply grease to a new dust seal lip and install the dust seal Special tool Oil seal and bearing install A120E00014 Apply the grease onto the bearings and oil seal lips of the frame Install s...

Page 195: ...r collar Install the steering bracket and tighten the two bolts Torque 22 N m 2 2 kgf m 16 lbf ft Install the tie rods and tighten the nuts Torque 35 N m 3 5 kgf m 25 lbf ft Install the cotter pin and...

Page 196: ...k the tie rod end movement Replace it if the tie rod end exists free play or turns roughly Check the tapered surface of the tie rod end Replace it if pitting wear or damage Adjust the tie rod length A...

Page 197: ...angle A 15 3 Torque 35 N m 3 5 kgf m 25 lbf ft INSTALLATION Install the tie rod and tighten the nuts Torque 35 N m 3 5 kgf m 25 lbf ft Install the cotter pins and band ends of cotter pin Refer to the...

Page 198: ...__________________ __________________________________________________________________________________ __________________________________________________________________________________ REAR WHEEL SWIN...

Page 199: ...13 REAR WHEEL SWING ARM HYDRAULIC BRAKE 13 1...

Page 200: ...uid with a clean towel Do not wipe the motorcycle with a towel contaminated by brake fluid Make sure to use recommended brake fluid Use of other unspecified brake fluids may cause brake failure Inspec...

Page 201: ...ston Brake fluid level too low Clogged hydraulic brake system Hydraulic brake system leakage Smooth or worn brake pad Hard braking Disk Brake Poor brake performance Disk Brake Seized hydraulic brake s...

Page 202: ...N Measure the wheel runout Service Limit Vertical 2 mm 0 08 in Lateral 2 mm 0 08 in Replace wheel if out of specification INSTALLATION Install the rear wheel and tighten the nuts wheel Torque 45 N m 4...

Page 203: ...hub nut First tighten the left wheel hub nut and then tighten the right wheel hub nut Torque 80 N m 8 kgf m 58 lbf ft Install the cotter pin and band ends of cotter pin Nut Cover Cotter Pin Washer Nut...

Page 204: ...e the collars on the rear axle right and left side Relax the drive chain Refer to the DRIVE CHAIN SLACK ADJUSTMENT section in chapter 3 Remove driven sprocket Remove the rear axle from right side Remo...

Page 205: ...ge Replace if splines and threads of the rear axle is wear or damage Measure the rear axle run out Service limit less than 1 5 mm 0 06 in Replace if it is out of specification Replace it if the driven...

Page 206: ...oil seal is wear or damage Replace it if rear axle hub is cracks bend or damage Bearing and oil seal replacement steps Clean the outside of the rear axle Remove the oil seal by a flat head screw driv...

Page 207: ...age 13 4 Adjust drive chain slack Refer to the DRIVE CHAIN SLACK ADJUSTMENT section in chapter 3 Approximately 10 20 mm 0 4 0 8 in At this time the rear axle hub should not be tightened completely Fin...

Page 208: ...section in chapter 13 Remove the lower bolt attaching the rear shock absorber Remove the upper bolt and then remove the shock absorber INSPECTION Check the tightening torque of the pivot shaft swing a...

Page 209: ...ical movement by moving it up and down If vertical movement is tight binding or rough to check the inner collar bushing and thrust cover INSPECTION Inspect the shock absorber rod Replace the shock abs...

Page 210: ...KE 13 12 REAR SWING ARM REMOVAL Remove the nut and pivot shaft then remove swing arm Remove the three bolts and chain guard Remove the drive chain Remove thrust covers and collar Nut Thrust Covers Swi...

Page 211: ...damage Inspect the thrust cover chain guide collar and bush Replace them if wear or damage Inspect the drive chain stiffness Clean and lubricate or replace it if stiff CLEAN Place it in kerosene and b...

Page 212: ...swing arm and tightening the nut Torque 70 N m 7 kgf m 50 lbf ft Install the shock absorber and tightening the bolts Torque 40 N m 4 kgf m 29 lbf ft This machine has a drive chain with small rubber O...

Page 213: ...d syringe to the brake caliper bleed valve and then loosen the bleed valve nut Fill the brake reservoir with brake fluid and use the syringe to draw brake fluid into it until there is no air bubbles i...

Page 214: ...ACEMENT Remove the two bolts attaching the brake caliper holder Remove the brake caliper Push the brake caliper holder and then remove brake pad Remove the other brake pad ASSEMBLY Assemble the brake...

Page 215: ...ke fluid from the hydraulic brake system Remove the two master cylinder holder bolts and remove the master cylinder Do not splash brake fluid onto any rubber plastic and coated parts When working with...

Page 216: ...from the brake master cylinder Remove the washer main piston and spring from the brake master cylinder Clean the inside of the master cylinder and brake reservoir with brake fluid I INSPECTION Check...

Page 217: ...e upper level Bleed air from the hydraulic brake system See page 13 15 Place the brake master cylinder on the handlebar and install the master cylinder holder with the UP mark facing up aligning the t...

Page 218: ...DISASSEMBLY Remove the brake caliper holder from the brake caliper Remove the pistons from the brake caliper Use compressed air to press out the pistons through the brake fluid inlet opening and plac...

Page 219: ...rease to the pistons and oil seals Lubricate the brake caliper cylinder inside wall with brake fluid Install the oil seals and then install the brake caliper pistons with the grooved side facing out W...

Page 220: ...d tube with groove in the caliper and tighten the fluid tube bolt Torque 35 N m 3 5 kgf m 25 lbf ft Add the recommended brake fluid into the brake reservoir and bleed air from the brake system Refer t...

Page 221: ...um is scratches polish brake drum lightly and evenly with emery cloth Measure the inside diameter of the brake drum Service limit 131 mm 5 24 in Replace it if it is out of specification Measure the fr...

Page 222: ...___ __________________________________________________________________________________ __________________________________________________________________________________ BATTER CHARGING SYSTEM A C GEN...

Page 223: ...4 BATTERY CHARGING SYSTEM A C GENERATOR 14 1 CHARGING CIRCUIT Regulator Rectifier A C Generator Regulator Rectifier A C Generator Headlight Switch Y R G Battery 12V4AH Y Auto Bystarter G B W G Resisto...

Page 224: ...w battery will prolong its service life Inspect the charging system according to the sequence specified in the Troubleshooting Do not disconnect and soon reconnect the power of any electrical equipmen...

Page 225: ...sal holder A120E00017 TROUBLESHOOTING No power Intermittent power Dead battery Loose battery cable connection Disconnected battery cable Loose charging system connection Fuse burned out Loose connecti...

Page 226: ...l BATTERY VOLTAGE OPEN CIRCUIT VOLTAGE INSPECTION Remove the seat See page 2 3 Disconnect the battery cables Measure the voltage between the battery terminals Fully charged 13 1V Undercharged 12 3V ma...

Page 227: ...ndard 5 10 hours Quick 30 minutes After charging Open circuit voltage 12 8 V min Keep flames and sparks away from a charging battery Turn power ON OFF at the charger not at the battery terminals to pr...

Page 228: ...LTAGE TEST This inspection must be performed with an electric tester when the battery is fully charged Warm up the engine for inspection Connect the electric tester across the battery terminals Attach...

Page 229: ...A C generator stator has resistance REGULATOR RECTIFIER INSPECTION If the main harness terminals are normal check the regulator rectifier coupler for loose connection and measure the resistances betw...

Page 230: ...stance between the A C generator yellow wire and engine ground with an electric tester YF 3501 tester Standard 1 4 20 C Replace the A C generator lighting coil if the reading is not within the specifi...

Page 231: ...ywheel nut Special tool Universal Holder A120E00017 Remove the A C generator flywheel using the flywheel puller Special tool Flywheel Puller A120E00001 Remove the pulser coil bolts Remove the A C gene...

Page 232: ...lbf ft Stator 10 N m 1 kgf m 7 lbf ft Connect the A C generator wire connector Clean the taper hole in the flywheel off any burrs and dirt Install the woodruff key in the crankshaft keyway Install the...

Page 233: ...11 Hold the flywheel with the universal holder and tighten the flywheel nut Torque 40 N m 4 kgf m 29 lbf ft Special tool Universal Holder A120E00017 Install the cooling fan Torque 8 N m 0 8 kgf m 6 lb...

Page 234: ...____________________________________________ __________________________________________________________________________________ ________________________________________________________________________...

Page 235: ...15 IGNITION SYSTEM 15 1 A C Generator Pulser Coil Spark Plug Ignition Coil...

Page 236: ...15 IGNITION SYSTEM 15 2 IGNITION CIRCUIT 90cc 70cc 50cc 4T IGNITION CIRCUIT 50cc 2T...

Page 237: ...Use of spark plug with improper heat range is the main cause of poor engine performance The inspections in this section are focused on maximum voltage The inspection of ignition coil resistance is als...

Page 238: ...unit ground wire Faulty ignition coil Dead battery or faulty regulator rectifier Faulty pulser coil Faulty ignition coil connector Normal high voltage but no spark at plug Faulty pulser coil Faulty sp...

Page 239: ...9 5 5 4 9 5 5 4 9 5 5 Note The readings in this table are taken with a YF 3501 Tester CDI Unit Green Black Black Yellow Blue Yellow Due to the semiconductor in circuit it is necessary to use a specifi...

Page 240: ...en Black Yellow Black Red 15 73 4 63 Black White 8 52 Blue Yellow Green 8 07 Note The readings in this table are taken with a YF 3501 Tester 50cc 2T ON ROAD Unit M Probe Probe Black Yellow Black Red B...

Page 241: ...70cc 50cc 4T 1 5 3 5 20 C 50cc 2T 3 7 15 2 20 C Measure the secondary coil resistances with and without the spark plug cap Resistances with plug cap 7 9 K 20 C without plug cap 2 5 K 20 C Note The rea...

Page 242: ...MING INSPECTION Remove the fan cover Warm up the engine and check the ignition timing with a timing light When the engine is running at the ignition timing is correct if the F mark aligns with the ind...

Page 243: ..._______________________________________ __________________________________________________________________________________ _____________________________________________________________________________...

Page 244: ...16 STARTING SYSTEM 16 1 STARTING CIRCUIT Starter Motor G G Y Ignition Switch Fuse Stop Switches R Y R Battery Starter Motor Starter Relay Rear G R W Front G Y Stoplight Start Switch...

Page 245: ...out Weak battery Weak battery Loose wire or connection Faulty ignition switch Foreign matter stuck in starter motor Faulty starter clutch or gear Faulty front or rear stop switch Faulty starter relay...

Page 246: ...ed parts for wear damage or discoloration and replace if necessary Clean the commutator if there is metal powder between the segments Check for continuity between pairs of the commutator segments and...

Page 247: ...the wire terminal and each brush Replace if necessary Measure the length of the brushes Service Limit 90cc 3 5 mm 0 14 in 70cc 50cc 2 5 mm 0 1 in Check for continuity between the brushes If there is c...

Page 248: ...Connect the starter motor cable connector Check the O ring for wear or damage and replace it if necessary Apply grease to the O ring and install the starter motor Tighten the two mounting bolts Torque...

Page 249: ...ircuit Check for continuity between the starter relay yellow red and green red wire terminals STARTER RELAY VOLTAGE INSPECTION Connect a 12V battery across the starter relay yellow red and green red w...

Page 250: ...emove the starter one way clutch drive nut with the special tool Special tool Universal holder A120E00017 Lock nut socket wrench A120E00015 Remove the starter gear Remove starter one way clutch drive...

Page 251: ...rder of removal INSPECTION Inspect the starter one way clutch drive gear teeth for burrs chips roughness wear Inspect the starter one way clutch drive gear contacting surfaces for pitting wear damage...

Page 252: ...lace it INSTALLATION Install the starter one way clutch drive gear onto the starter one way clutch Install the lock nut but do not need tighten it Install the starter clutch assembly onto the cranksha...

Page 253: ...NSPECTION Inspect the starter pinion seat for wear Inspect the starter pinion for smooth operation Inspect the starter pinion shaft forcing parts for wear and damage INSTALLATION Apply a small amount...

Page 254: ...____________________________________________________________________ __________________________________________________________________________________ ________________________________________________...

Page 255: ...with a new one Install the bulb aligning the bulb socket groove with the bulb tab and set the lock clip Install the rubber boot Install the front fender in the reverse order of removal TAIL BRAKE LIG...

Page 256: ...ON ROAD ONLY Pull the bulb socket out of the position light case Pull the bulb out of the socket and replace it with a new one Installation is in the reverse order of removal FRONT TURN SIGNAL LIGHT O...

Page 257: ...the turn signal lens groove with the turn signal case tab REAR TURN SIGNAL LIGHT ON ROAD ONLY Remove the screw and remove the turn signal light lens Pull the bulb socket outside from the signal light...

Page 258: ...ect the meter connectors Remove the two screws and then remove the instrument Installation is in the reverse order of removal HORN ON ROAD REMOVAL Disconnect the horn wire connectors Remove the bolt a...

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KYMCO Mongoose 50-2T, Service Manual

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