Page 1 Foreword This service manual provides maintenance guidelines for KYMCO AHG1 fuel injection Quick Reference engine. External Components Chapter 1 contains all the operational Periodic Maintenance precautions that you should read carefully Lubrication System before you start. Engine Removal/ Installation Chapter 3 gives inspection and fine-tuning tips...
Page 2: Table Of Contents
1. Quick Reference Quick Reference Engine /Frame Serial Number ....................... 2 Specifications .............................. 3 Operation precautions ..........................4 Torque ................................5 4.1. General Torque Value ........................5 4.2. Engine ............................... 6 4.3. Frame ..............................7 Special Tool ..............................8 LUBRICATION POINTS-FRAME ......................9 Components Location ...........................
Page 3: Engine /Frame Serial Number
1. Quick Reference 1. Engine /Frame Serial Number Frame Serial Number Engine Serial Number...
Page 4: Specifications
1. Quick Reference 2. Specifications Cooling Type Liquid Cooling Model Code AHG1 Overall Length (mm) 2165 Coolant radiator 0.87L Overall Width (mm) Coolant Overall High (mm) 1290 capacity Reserve tank 0.49L Wheel Base (mm) 1545 Engine Type Four Stroke OHC Air cleaner type &...
Page 5: Operation Precautions
1. Quick Reference 3. Operation precautions If any gaskets, O-rings circlips and cotter pins are removed, they need to be replaced with new ones. Tighten the screws and nuts from the one with bigger outer diameter diagonally to the specified torque. recommend that genuine...
Page 6: Torque
1. Quick Reference 4. Torque 4.1. General Torque Value Torque (kgf∙m) Torque (kgf∙m) Item Item 5mm Bolt/ Nut 0.45~0.6 4mm Tapping screw (Cut) 0.05~0.15 6mm Bolt/ Nut 0.8~1.2 4mm Tapping screw (Point) 0.2~0.4 8mm Bolt/ Nut 1.8~2.5 5mm screw (Cut) 0.1~0.3 10mm Bolt/ Nut 3.0~4.0...
Page 7: Engine
1. Quick Reference 4.2. Engine TORQUE ITEM Remarks DWG No. Kgf-m Bolt B Stud 8*210 6.9~10.8 0.7~1.1 Stud side 90032-KHD6-9000 Bolt B Stud 8*218 6.9~10.8 0.7~1.1 Stud side 90031-KHD6-9000 Tappet ADJ hole cap 9.8~19.6 1.0~2.0 12361-GFY6-9010 L Cover 7.8~8.8 0.8~0.9 9000A-KTDT-9000 Tube/ wire clamper 7.8~8.8...
Page 8: Frame
1. Quick Reference 4.3. Frame TORQUE ITEM Remarks DWG No. Kgf-m Steering Nut STRG, Stem lock 58.8~68.6 6.0~7.0 90106-PUA3-B000-IN BOT, bridge (Fork pipe) 23.5~29.4 2.4~3.0 95801-08040-08G Stem lock 58.8~63.7 6.0~6.5 50306-IF96-C000 Race nut (Head) 17.7~21.6 1.8~2.2 53220-LBA2 Handle 49.0~58.8 5.0~6.0 94001-1008G-0S Wheel RR wheel axle nut...
Page 9: Special Tool
1. Quick Reference 5. Special Tool Tool Name Tool No. Performance Photo A.C. generator flywheel Flywheel Puller A120E00003 removal Tappet Adjuster A120E00012 Tappet adjustment Oil Seal & Bearing A120E00014 Oil seal & bearing installing Installer A.C. generator flywheel Flywheel Holder A120E00021 holding Clutch disassembly &...
Page 10: Lubrication Points-Frame
1. Quick Reference 6. LUBRICATION POINTS-FRAME The following is the lubrication points for the frame. Use grease for parts not listed. Apply engine oil or grease to cables and movable parts not specified. It will avoid abnormal noise and damage the durability of the motorcycle. : Grease : Engine Oil Throttle...
Page 11: Components Location
1. Quick Reference 7. Components Location Right handlebar Left handlebar Rear brake Front brake switch switch fluid reservoir fluid reservoir USB charger wires Front brake fluid hose Rear brake fluid hose Start relay OBD connector Coolant filling cap Fuse box 1-10...
Page 12 1. Quick Reference Throttle body ISC (Idle air bypass valve) Fuel injector Fuel hose PPTS (Intake air temp/MAP/TPS) Throttle cables Fuel pump Thermostat Inductive ignition coil Spark plug Canister Rectifier/Regulator Hazard light controller 1-11...
Page 13 1. Quick Reference Long-distance Tilt switch Ignition antenna switch USB charger controller Engine oil indicator controller KEYLESS Headlight controller controller Start relay Coolant reserve tank Battery box ABS controller Coolant radiator 1-12...
Page 14: General Troubleshooting
1. Quick Reference 8. General Troubleshooting 8.1. Engine lacks power 1-13...
Page 15 1. Quick Reference 1-14...
Page 16: Engine Will Not Stat Or Is Hard To Start
1. Quick Reference 8.2. Engine will not stat or is hard to start 1-15...
Page 17: Poor Handling
1. Quick Reference 8.3. Poor handling 1-16...
Page 18: Poor Performance At High Speed
1. Quick Reference 8.4. Poor performance at high speed 1-17...
Page 19: Poor Performance At Low And Idle Speed
1. Quick Reference 8.5. Poor performance at low and idle speed 1-18...
Page 20 2. External components, Exhaust pipe...
Page 21 2. External components, Exhaust pipe...
Page 22 2. External components, Exhaust pipe Service Information ................................. 3 1.1. General Instructions ..............................3 1.2. Torque value ................................3 1.3. Troubleshooting ............................... 3 External Components Removal ............................4 2.1. Wind screen................................4 2.2. Front cover .................................. 4 2.3. Headlight assy ................................4 Side covers ..................................
Page 23: Service Information
2. External components, Exhaust pipe 1. Service Information 1.1. General Instructions  When removing frame covers, use care not to pull them by force because the cover joint claws may be damaged.  Make sure to route cables and harnesses according to the Cable & Harness Routing. 1.2.
Page 24: External Components Removal
2. External components, Exhaust pipe 2. External Components Removal 2.1. Wind screen Remove the bolts and Allen bolts. Remove the wind screen and brackets. Install in the reverse order of work. 2.2. Front cover Remove the plastic screws. Remove the screws. Remove the front cover.
Page 25: Side Covers
2. External components, Exhaust pipe Remove the screws on each side of cover. Remove the leg shields mat and floor mats o each side of cover. Remove the screws. Side covers Remove the plastic screws on each side of the under cowl.
Page 26: Seat
2. External components, Exhaust pipe 2.4. Seat Open the seat. Remove the nuts. Remove the seat. Install in the reverse order of work. 2.5. Luggage box Remove the bolts and nuts. Disconnect the luggage box light connector. Remove the luggage box. Install in the reverse order of work.
Page 27: Tail Light Assy
2. External components, Exhaust pipe 2.8. Tail light assy Remove the center rubber cover. Remove the bolt. Remove the plastic screws on the upper and down side of each side cover. Disconnect all connectors of tail light assy. Remove the tail light assy. Install in the reverse order of work.
Page 28: Meter Cover
2. External components, Exhaust pipe Remove the bolts on each side of floor panels. Remove the plastic screw on each side of the leg shield. Remove the floor panel assy. Install in the reverse order of work. 2.10. Meter cover Remove the wind screen.
Page 29 2. External components, Exhaust pipe Loosen the screw of ignition switch cover. Turn the cover counterclockwise. Pull out the cover but do not over pull it. Disconnect the connector. Remove the ignition switch cover. Key cover Use a proper tool to pry out the lid. Remove the key cover.
Page 30: Leg Shield
2. External components, Exhaust pipe 2.11. Leg shield Remove the bolt on each side of the cover. Remove the cable of the fuel filling cap cover. Remove the leg shield. Install in the reverse of work. 2.12. Handlebar covers Remove the bolts on each side of lower handlebar cover.
Page 31: Front Fender
2. External components, Exhaust pipe 2.13. Front fender Remove the Allen bolt and the bolt on each side of the front fender. Remove the front fender. Install in the reverse order of work. 2.14. Rear fenders Remove the bolts on the lower rear fender. Remove the lower rear fender.
Page 32: Undercover
2. External components, Exhaust pipe 2.15. Undercover Remove the bolts on each side of the undercover. Remove the undercover. Install in the reverse order of work. 2.16. Muffler cover Remove the bolts. Remove the muffler cover. Install in the reverse order of work. 2-12...
Page 33: Exhaust Assembly
2. External components, Exhaust pipe 3. Exhaust assembly 3.1. Muffler Remove the Allen bolt. Remove the bolts. Remove the muffler Install in the reverse order of work. 3.2. Exhaust pipe Nuts Remove the muffler. Disconnect the O2 sensor connector. Remove the nuts on the front end of the exhaust pipe.
Page 34 3. PERIODIC MAINTENANCE Periodic Maintenance Service Information ..................... 3 1.1. Warning ......................3 1.2. Specifications ....................3 Maintenance Schedule ....................4 2.1. Irregular Maintenance ..................5 2.2. Notes ........................ 5 Fuel Line ........................6 Throttle Operation ....................... 6 Air Cleaner ........................7 Spark Plug ........................
Page 35 3. PERIODIC MAINTENANCE 16.1. Brake fluid ....................19 16.2. Brake pad wear ................... 19 16.3. Brake levers ....................20 17. Nuts/Bolts/Fasteners ....................20 18. Wheels/Tires ......................21 18.1. Tire pressure ....................21 19. Steering Handlebar ....................21 20. Suspension ....................... 22 20.1.
Page 36: Service Information
3. PERIODIC MAINTENANCE 1. Service Information 1.1. Warning  Before running the engine, make sure that the working area is well-ventilated. Never run the engine in a closed area. The exhaust contains poisonous carbon monoxide gas which may cause death to people. ...
Page 37: Maintenance Schedule
3. PERIODIC MAINTENANCE 2. Maintenance Schedule Perform the pre-ride inspection at each scheduled maintenance period. This interval should be judged by odometer reading or months, whichever comes first. I: INSPECT AND CLEAN, ADJUST, LUBRICATE OR REPLACE IF NECESSARY C: CLEAN R: REPLACE T: Tighten M: Maintain D: Diagnostic Maintenance Operation Item Maintenance Interval Mileage 300 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000 12000...
Page 38: Irregular Maintenance
5000 km. Replace the sensor when necessary. 2.2. Notes 1. We recommend that you add a bottle of KYMCO fuel injector cleaner every 1000 km to the fuel tank. 2. An air blow gun must be used to clean the dust and foreign objects inside the belt wheel for models with rear wheel driving belt.
Page 39: Fuel Line
3. PERIODIC MAINTENANCE 3. Fuel Line Check the fuel lines and replace any parts which show signs of deterioration, damage or leakage. 4. Throttle Operation Check throttle grip smooth movement. Measure the throttle grip free play. Free Play: 2～6 mm Major adjustment of the throttle grip free play is made with the adjusting nut at the throttle valve.
Page 40: Air Cleaner
3. The new air cleaner element installation is in the reverse order of removal. Use the KYMCO genuine air cleaner element or an equivalent air cleaner element specified for your model. Using the wrong KYMCO...
Page 41: Valve Clearance
3. PERIODIC MAINTENANCE 7. Valve Clearance 7.1. Inspection  Inspect and adjust valve clearance while the engine is cold (below 35 ℃). Remove the four bolts, and then remove cylinder head cover. Remove the timing inspection cap from the right side of the engine with a large flat blade screwdriver.
Page 42: Adjustment
3. PERIODIC MAINTENANCE 7.2. Adjustment Place a 9 mm box end wrench over the locknut, and loosen the locknut. If the valve clearance is tight back out the valve tappet adjusting screw with the tappet adjustment tool. If the clearance is too loose turn in the adjusting screw until there is a light drag on the feeler gauge.
Page 43: Engine Oil
3. PERIODIC MAINTENANCE 9. Engine Oil 9.1. Engine oil Engine oil capacity: At disassembly: recommendation 1.2 L (0.968 lmp qt, 1.166 US qt) Use a premium quality 4-stroke motor oil to At change: ensure longer service life of your scooter. 1.0L Use only oils which are rated, SJ under the service...
Page 44: Engine Oil Replacement
3. PERIODIC MAINTENANCE 9.3. Engine oil replacement Used engine oil may cause skin cancer if Engine oil quality is the chief factor affecting repeatedly left in contact with the skin for engine service life. Change the engine oil as prolonged periods. Although this is unlikely specified in the maintenance schedule.
Page 45: Oil Strainer Screen Clean
3. PERIODIC MAINTENANCE 9.4. Oil strainer screen clean Change the engine oil with the engine at normal operating temperature and the scooter on its center stand to assure complete and rapid draining.  Let the engine and exhaust system cool before working in those areas. 1.
Page 46: Oil Filter Replacement
3. PERIODIC MAINTENANCE 9.5. Oil filter replacement Change the engine oil with the engine at normal operating temperature and the scooter on its center stand to assure complete and rapid draining.  Let the engine and exhaust system cool before working in those areas. 1.
Page 47 3. PERIODIC MAINTENANCE 5. Install the new oil filter.  Make sure the rubber seal on the oil filter facing the left crankcase. 6. Install the spring, O-ring and cap. Cap bolt torque: 1.2 kgf-m 7. Fill the crankcase with the recommended grade oil and install the oil filler cap.
Page 48: Transmission Oil
3. PERIODIC MAINTENANCE Transmission Oil 10.1. Oil change 1. Place the scooter in its center stand. 2. Place a drain pan under the drain bolt (1). 3. Remove the transmission oil drain bolt. 4. Remove the transmission oil filler bolt (2), slowly turn the rear wheel and drain the oil.
Page 49: Idle Speed
3. PERIODIC MAINTENANCE Idle Speed  It is not necessary to adjust idle Idle Speed: 1700±100 rpm speed for DOWNTOWN125i. The throttle body is factory pre-set, do not loosen or tighten the painted bolts and screws of throttle body. Loosening or tightening them can cause throttle and idle and valve synchronization failure.
Page 50: Headlight Aim
If the reserve tank is empty, or if coolant loss is excessive, check for leaks and see your KYMCO dealer for repair. 15.2. Add coolant Remove the screw (1). Press the cover at (2) part to release the joint claw.
Page 51: Coolant Recommendation
3. PERIODIC MAINTENANCE Remove the reserve tank cap to add coolant mixture until it reaches the F level mark.  Removing the cap while the engine is hot that can cause the coolant to spray out, seriously scalding you. Always let the engine and radiator cool down before removing the cap.
Page 52: Brake
Inspect the pads at each regular maintenance interval. Front brake Check the cutout in each pad. If either pad is worn to the cutout, replace both pads as a set. See your KYMCO dealer for this service. 3-19...
Page 53: Brake Levers
3. PERIODIC MAINTENANCE Rear brake Check the cutout in each pad. If either pad is worn to the cutout, replace both pads as a set. See your KYMCO dealer for this service. 16.3. Brake levers 1. Adjust brake lever clearance using adjustment knob (totally 4 adjustment positions).
Page 54: Wheels/Tires
3. PERIODIC MAINTENANCE Wheels/Tires 18.1. Tire pressure Insufficient air pressure in the tires not only hastens tire wear but also seriously affects the stability of the scooter. Under inflated tires make smooth cornering difficult and overinflated tires decrease the amount of tire in contact with the ground which can lead to skids and loss of control.
Page 55: Suspension
3. PERIODIC MAINTENANCE Suspension Check the action of the front/rear shock absorbers by compressing them several times. Check the entire shock absorber assembly for oil leaks, looseness or damage. Jack the rear wheel off the ground and move the rear wheel sideways with force to see if the engine hanger bushings are worn.
Page 56: Side Stand
2. Put the side stand up and start the engine. 3. Lower the side stand. The engine should stop as you put the side stand down. If the side stand system does not operate as described, see your KYMCO dealer for service. Side Stand Down 3-23...
Page 57 4. LUBRICATION SYSTEM Lubrication System...
Page 58 4. LUBRICATION SYSTEM Lubrication Diagram ........................3 SERVICE INFORMATION ........................ 4 2.1. GENERAL INSTRUCTIONS ....................4 2.2. SPECIFICATIONS ........................ 4 2.3. TROUBLESHOOTING ......................5 Engine oil ............................6 Oil Pump ............................6 4.1. Removal ..........................6 4.2. Disassembly ........................7 4.3.
Page 59: Lubrication Diagram
4. LUBRICATION SYSTEM 1. Lubrication Diagram Rocker Arm Shaft Crankshaft Oil Strainer Screen Oil Pump Oil Filter Screen...
Page 60: Service Information
4. LUBRICATION SYSTEM 2. SERVICE INFORMATION 2.1. GENERAL INSTRUCTIONS  The maintenance of lubrication system can be performed with the engine installed in the frame.  Drain the coolant before starting any operations.  Use care when removing and installing the oil pump not to allow dust and foreign matters to enter the engine and oil line.
Page 61: Troubleshooting
4. LUBRICATION SYSTEM 2.3. TROUBLESHOOTING Oil level too low  Natural oil consumption  Oil leaks  Worn piston rings  Worn valve guide  Worn valve guide seal Poor lubrication pressure  Oil level too low Clogged oil filter or oil passage ...
Page 62: Engine Oil
4. LUBRICATION SYSTEM 3. Engine oil See the chapter 3 for more information. 4. Oil Pump 4.1. Removal Bolts Drain the engine oil. Remove the alternator cover, fly wheel, starter idle gear, shaft, pins and starter driven gear. Remove the bolt and then oil pump cover. Oil Pump Cover Pry the snap ring off and remove the oil Oil Pump Driven Gear...
Page 63: Disassembly
4. LUBRICATION SYSTEM 4.2. Disassembly Remove the screw and disassemble the oil pump as shown. Inner Rotor Screw Pump Body Pump Cover Dowel Pin Outer Rotor Pump Shaft 4.3. Inspection Pump Body Outer Rotor Measure the pump body-to-outer rotor clearance. Measure the inner rotor-to-outer rotor Pump Body Inner Rotor...
Page 64: Assembly
4. LUBRICATION SYSTEM Measure the rotor end-to-pump body clearance. Pump Body Rotor End 4.4. Assembly Pump Body Dowel Pin Install the outer rotor, inner rotor and pump shaft into the pump body.  Insert the pump shaft by aligning the flat on the shaft with the flat in the inner rotor.
Page 65: Installation
4. LUBRICATION SYSTEM 4.5. Installation Oil Pump Install the oil pump and oil pump and tighten the two bolts.  Make sure the pump shaft rotates freely and arrow mark which is on the oil pump is upside. Bolts Install the pump drive chain and driven Oil Pump Driven Gear sprocket, then set the snap ring securely on the pump shaft.
Page 66 5. ENGINE Engine ENGINE REMOVAL/INSTALLATION ....................4 1.1. Removal ..........................4 1.2. Installation ........................6...
Page 67 5. ENGINE SERVICE INFORMATION GENERAL INSTRUCTIONS  A floor jack or other adjustable support is required to support and maneuver the engine. Be careful not to damage the scooter body, cables and wires during engine removal.  Use shop towels to protect the scooter body during engine removal. ...
Page 68 5. ENGINE SPECIFICATIONS at disassembly 1.2 L ENGINE OIL CAPACITY at change 1.0 L Radiator capacity + hoses 0.87 L COOLANT CAPACITY Reserve tank capacity 0.49 L Engine hanger bolts (Engine side) 5.0 kgf-m Engine hanger bolts (Frame side) 6.5 kgf-m Engine rear suspension mounting bolts 3.5 kgf-m TORQUE VALUES...
Page 69 5. ENGINE 1. ENGINE REMOVAL/INSTALLATION 1.1. Removal WTS connector Fuel hose holder Remove the air cleaner. Remove a bolt from fuel hose holder. Disconnect the following connectors: - Idle air bypass valve - TPS - WTS - MAP - Intake air pressure sensor - O2 sensor - Rectifier/ Regulator - Fuel injector...
Page 70 5. ENGINE Loosen the rear axle nut. Support the scooter securely on its main stand. Remove the bolts, and then remove the rear brake caliper. Rear brake caliper bolts Disconnect the alternator cord including the crank position sensor cord. Remove the spark plug cap. Remove the bolts.
Page 71 5. ENGINE Remove the engine mount nut. Pull out the engine mount bolt. Remove the engine from the frame.  At removing the engine, be careful not to catch your hand or finger between the engine hanger and crankcase. 1.2. Installation Tighten the engine mounting bolts.
Page 72 6. CYLINDER HEAD/ VALVE Cylinder Head/ Valve SCHEMATIC DRAWING ..................... 2 SERVICE INFORMATION ................... 3 2.1. General Instructions ..................3 2.2. Specifications ....................3 2.3. Torque Values ....................4 2.4. Special Tools..................... 4 2.5. Troubleshooting ....................5 CYLINDER HEAD COVER ..................6 3.1.
Page 73: Schematic Drawing
6. CYLINDER HEAD/ VALVE 1. SCHEMATIC DRAWING...
Page 74: Service Information
6. CYLINDER HEAD/ VALVE 2. SERVICE INFORMATION 2.1. General Instructions  The cylinder head can be serviced with the engine installed in the frame. Coolant in the radiator and water jacket must be drained first.  When assembling, apply molybdenum disulfide grease or engine oil to the valve guide movable parts and valve arm sliding surfaces for initial lubrication.
Page 75: Torque Values
6. CYLINDER HEAD/ VALVE 2.3. Torque Values Item Value Remark 0.8~0.9 kgf-m Cylinder head cover bolt Tensioner mounting bolt 1.0~1.4 kgf-m Tensioner sealing bolt 0.5~0.5 kgf-m Cylinder head nut 1.8~2.2 kgf-m Cylinder head bolt 0.7~1.1 kgf-m Valve clearance fixing nut 0.7~1.1 kgf-m Apply engine oil to threads 2.4.
Page 76: Troubleshooting
6. CYLINDER HEAD/ VALVE 2.5. 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 Compression too low White smoke from exhaust muffler Worn valve stem or valve guide Damaged valve stem oil seal Compression too low Incorrect valve clearance adjustment...
Page 77: Cylinder Head Cover
6. CYLINDER HEAD/ VALVE 3. CYLINDER HEAD COVER 3.1. Removal Remove the four bolts then remove the cylinder head cover. 3.2. Installation Install a new cylinder head cover O-ring and install the cylinder head cover.  Be sure to install the O-ring into the groove properly Install and tighten the cylinder head cover bolts to the specified torque in a...
Page 78: Camshaft Holder
6. CYLINDER HEAD/ VALVE 4. CAMSHAFT HOLDER 4.1. Removal Turn the A.C. generator fly wheel so that the T mark on the flywheel aligns with the index mark on the crankcase. Hold the round hole on the camshaft gear facing up and location is the top dead center on the compression stroke.
Page 79: Disassembly
6. CYLINDER HEAD/ VALVE 4.3. Disassembly Take out the valve rocker arm shafts Remove the valve rocker arms. Rocker Arm Shaft 4.4. Inspection Inspect the camshaft holder, valve Camshaft Holder rocker arms and rocker arm shafts for wear or damage. ...
Page 80: Assembly
6. CYLINDER HEAD/ VALVE Measure the I.D. of each valve rocker arm. Service Limits: IN: 10.1 mm EX: 10.1 mm Measure each rocker arm shaft O.D. Service Limits: IN: 9.9 mm EX: 9.9 mm Measure arm to shaft clearance. Replace as a set if out of specification. Service limits: 0.1 mm 4.5.
Page 81: Camshaft
6. CYLINDER HEAD/ VALVE 5. CAMSHAFT 5.1. Removal Turn the A.C. generator flywheel so that the “T” mark on the flywheel aligns with the index mark on the crankcase. Hold the round hole on the camshaft gear facing up and the location is the top dead center on the compression stroke.
Page 82: Inspection
6. CYLINDER HEAD/ VALVE 5.2. Inspection Camshaft Inspect camshaft lobes for pitting/scratches/blue discoloration. Measure the cam lobe height. Service Limits: IN : 25.57 mm EX: 25.41 mm If any defects are found, replace the camshaft with a new one, and then inspect lubrication system.
Page 83: Disassembly
6. CYLINDER HEAD/ VALVE Install the camshaft gear 5.4. Disassembly Remove the valve spring cotters, Valve Spring Compression retainers, springs, spring seats, oil seals and valves using a valve spring compressor.  Be sure to compress the valve springs with valve spring compressor.
Page 84: Inspection
6. CYLINDER HEAD/ VALVE 5.5. Inspection Remove carbon deposits from the exhaust port and combustion chamber.  Be careful not to damage the cylinder head mating surface. Valve/ Valve Guide Inspect each valve for bending, burning, scratches or abnormal stem wear.
Page 85: Cylinder Head
6. CYLINDER HEAD/ VALVE Cylinder Head Check the spark plug hole and valve areas for cracks. Check the cylinder head for warpage with a straight edge and feeler gauge. Service Limit: 0.05 mm 5.6. Assembly Install the valve spring seats and oil Valve Spring Compression seal.
Page 86 7. CYLINDER/ PISTON Cylinder/ Piston SCHEMATIC DRAWING ......................... 2 SERVICE INFORMATION ........................ 3 2.1. General Instructions ......................3 2.2. Specifications ........................3 2.3. Troubleshooting ....................... 4 Cylinder and Piston ........................5 3.1. Removal ..........................5 3.2. Inspection ......................... 6 Piston ring ..........................6 Piston/Piston pin ........................
Page 87: Schematic Drawing
7. CYLINDER/ PISTON 1. SCHEMATIC DRAWING...
Page 88: Service Information
7. CYLINDER/ PISTON 2. SERVICE INFORMATION 2.1. General Instructions  The cylinder and piston can be serviced with the engine installed in the frame.  When installing the cylinder, use a new cylinder gasket and make sure that the dowel pins are correctly installed.
Page 89: Troubleshooting
7. CYLINDER/ PISTON 2.3. Troubleshooting When hard starting or poor performance at low speed occurs, check the crankcase breather for white smoke. If white smoke is found, it means that the piston rings are worn, stuck or broken. Compression too low or uneven compression ...
Page 90: Cylinder And Piston
7. CYLINDER/ PISTON 3. Cylinder and Piston 3.1. Removal Remove the cylinder head Remove the water hose from the cylinder. Remove the cylinder. Remove the cylinder gasket and dowel pins. Clean any gasket material from the cylinder surface. Remove the piston pin clip ...
Page 91: Inspection
7. CYLINDER/ PISTON Spread each piston ring and remove it by lifting up at a point opposite the gap  Do not damage the piston ring by spreading the ends too far. Clean carbon deposits from the piston ring grooves. 3.2.
Page 92: Piston/Piston Pin
7. CYLINDER/ PISTON Piston/Piston pin Measure the piston O.D. at the point (A) 10 mm from the bottom and 90° to the piston pin hole. Calculate the cylinder-to-piston clearance. Measure the piston pin hole. Take the maximum reading to determine the I.D. Service Limit: 15.04 mm (0.6016 in) Measure the piston pin O.D.
Page 93 7. CYLINDER/ PISTON Take a maximum reading to determine the clearance. Calculate the taper and out-of-round at three levels in an X and Y axis. Take the maximum reading to determine them. Measure the connecting rod small end I.D. Calculate the connecting rod-to-piston pin clearance.
Page 94: Installation
7. CYLINDER/ PISTON 3.3. Installation Piston ring Carefully install the piston rings into the piston ring grooves with the markings facing  Be careful not to damage the piston and rings.  Do not confuse the top and second rings. ...
Page 95: Cylinder/Piston
7. CYLINDER/ PISTON Place a clean shop towel over the crankcase prevent the clip from falling into the crankcase. Install the new pin clip.  Make sure that the piston pin clips are seated securely.  Do not align the piston pin clip end gap with the piston cut-out Install the dowel pins and gasket.
Page 96 8. DRIVE & DRIVEN PULLEYS Drive & Driven Pulleys SCHEMATIC DRAWING ..................... 2 SERVICE INFORMATION ................... 3 2.1. General Instructions ..................3 2.2. Specifications ....................3 2.3. Torque Values ....................3 2.4. Special Tools..................... 3 2.5. Troubleshooting ....................4 Left Crankcase Cover ....................5 3.1.
Page 97: Schematic Drawing
8. DRIVE & DRIVEN PULLEYS 1. SCHEMATIC DRAWING...
Page 98: Service Information
8. DRIVE & DRIVEN PULLEYS 2. SERVICE INFORMATION 2.1. General Instructions  The drive pulley, clutch and driven pulley can be serviced with the engine installed.  Avoid getting grease and oil on the drive belt and pulley faces. Remove any oil or grease from them to minimize the slipping of drive belt and drive pulley.
Page 99: Troubleshooting
8. DRIVE & DRIVEN PULLEYS 2.5. Troubleshooting Engine starts but motorcycle won‘t move  Worn drive belt  Broken ramp plate  Worn or damaged clutch lining  Broken driven face spring Engine stalls or motorcycle creeps  Broken clutch weight spring Lack of power ...
Page 100: Left Crankcase Cover
8. DRIVE & DRIVEN PULLEYS 3. Left Crankcase Cover 3.1. Removal Remove the 10 left crankcase cover bolts and then remove the left crankcase cover. Remove the gasket and dowel pins. 3.2. Installation Install the dowel pins and gasket. Install the left crankcase cover. Install and tighten the 10 bolts diagonally to specified torque.
Page 101: Drive Pulley, Drive Belt And Driven Pulley
8. DRIVE & DRIVEN PULLEYS 4. Drive Pulley, Drive Belt and Driven Pulley 4.1. Removal Remove the left crankcase cover (refer to the “LEFT CRANKCASE COVER” section in this chapter). Use the special tool to hold the drive pulley, and then remove the nut and ratchet. Special tool: Universal holder A120E00017...
Page 102 8. DRIVE & DRIVEN PULLEYS Remove the movable drive face assembly. Drive belt inspection Check the drive belt for cracks, separation or abnormal or excessive wear. Measure the drive belt width. ※ Use specified genuine parts for replacement. Clutch out inspection Inspect the clutch outer for wear or damage.
Page 103: Installation
8. DRIVE & DRIVEN PULLEYS 4.2. Installation Apply lubricant to the drive face boss inner surface then install the movable drive face assembly. Install the clutch outer onto the driven pulley assembly. Compress the driven pulley assembly by hand then install the drive belt into the driven pulley assembly.
Page 104: Drive Pulley
8. DRIVE & DRIVEN PULLEYS Install the drive pulley face and ratchet. Use the special tool to hold drive pulley face, and then tighten the nut to the specified torque. Torque: 5.5~6.5 kgf-m (55~65 N-m) Special tool: Universal holder A120E00017 5.
Page 105: Inspection
8. DRIVE & DRIVEN PULLEYS Remove the six weight rollers. 5.2. Inspection Weight rollers Check each roller for wear or damage. Measure outside diameter. Service limit: 19.8 mm (0.792 in) Movable drive face/Slide pieces/Drive pulley face Check the movable drive face splines for wear, cracks or damage.
Page 106: Assembly
8. DRIVE & DRIVEN PULLEYS 5.3. Assembly Clean the movable drive face, drive pulley face, weight rollers, slide pieces, ramp plate and drive face boss. ※ Remove any excess grease. Install the weight rollers. ※ The direction of all weight rollers is the same.
Page 107: Driven Pulley
8. DRIVE & DRIVEN PULLEYS 6. Driven Pulley 6.1. Disassembly Hold the clutch/driven pulley assembly with the clutch spring compressor. ※ Be sure to use a clutch spring compressor to avoid spring damage. Special tool: Clutch Spring Compressor A120E00034 Set the tool in a vise and remove the clutch drive plate nut.
Page 108: Inspection
8. DRIVE & DRIVEN PULLEYS Needle Bearing Bearing Guide Pins/ Rollers Dust Seal Spring Collar Spring Snap Bearing Dust Seal Driven Face O-ring Movable Driven Face 6.2. Inspection Check the driven pulley for smooth operation. If any scratches or damage is found then replace as a set.
Page 109: Assembly
8. DRIVE & DRIVEN PULLEYS Check the clutch shoe for heat damage. Measure the clutch shoe thickness. 6.3. Assembly Apply Grease Clean any oil from the drive belt sliding surfaces on the driven face. Filling 12 g of grease to driven face inner side. Apply grease to lips of the new dust seals and install into the movable driven face.
Page 110 9. FINAL REDUCTION Final Reduction SCHEMATIC DRAWING ..................... 2 SERVICE INFORMATION ................... 3 2.1. General Instructions ..................3 2.2. Specifications ....................3 2.3. Torque Values ....................3 2.4. Special Tools..................... 3 2.5. Troubleshooting ....................3 GEAR OIL ........................4 3.1. Draining ......................
Page 111: Schematic Drawing
9. FINAL REDUCTION 1. SCHEMATIC DRAWING...
Page 112: Service Information
9. FINAL REDUCTION 2. SERVICE INFORMATION 2.1. General Instructions  The servicing operations of this section can be made with the engine installed.  When replacing the drive shaft, use a special tool to hold the bearing inner race for this operation.
Page 113: Gear Oil
9. FINAL REDUCTION 3. GEAR OIL 3.1. Draining Place the vehicle on its center stand on level ground. Place a suitable oil drain pan under the transmission oil drain plug. Remove the transmission oil level filler bolt with a 12 mm socket. Place a suitable container under the drain plug to capture the final drive oil.
Page 114 9. FINAL REDUCTION Inspect the drain plug and washer. Install the oil drain plug and washer with a 12 mm socket. Tighten to specification. Torque Thread Item size (mm) kgf-m lb-ft Final drive oil drain bolt 0.8 - 1.2 5.79 - 8.68...
Page 115: Filling
9. FINAL REDUCTION 3.2. Filling Fill the final drive with the specified quantity of oil with a syringe. Gear oil type: SAE 90 Gear oil capacity: At disassembly 0.13 Liter At change 0.12 Liter Thread in the final drive oil level filler bolt.
Page 116 9. FINAL REDUCTION Install the oil filler plug and torque it to specification with a 12 mm socket. Torque Thread Item size (mm) kgf-m lb-ft Final drive oil filler bolt 0.8 - 1.2 5.79 - 8.68...
Page 117: Final Reduction
9. FINAL REDUCTION 4. FINAL REDUCTION 4.1. Removal Drain the transmission gear oil into a clean container Remove the driven pulley Remove the nine bolts from the transmission case cover, then remove transmission case cover. Remove the dowel pins and gasket. Gasket Dowel Pin Final Gear...
Page 118: Inspection
9. FINAL REDUCTION 4.2. Inspection Inspect the countershaft and gear for wear or damage. Inspect the final gear and final gear shaft for wear, damage or seizure. Check the driveshaft for wear or damage. Check the left crankcase bearings for excessive play and inspect the oil seal for wear or damage.
Page 119: Installation
9. FINAL REDUCTION Final Gear Shaft Bearing Drive Shaft Bearing Counter Shaft Bearing 4.3. Installation Gasket Dowel Pin Final Gear Install the final gear and final gear shaft. Install the Countershaft Install the driveshaft. Install new gasket. Install the two dowel pins. Counter Shaft Drive Shaft Install the transmission case cover.
Page 120: Bearing Replacement
9. FINAL REDUCTION 5. BEARING REPLACEMENT 5.1. Transmission Case Cover Remove the transmission case cover Remove the transmission case cover bearings by using the special tool. Special tool: Bearing puller A120E00037 Install the new bearings or new oil seal into the transmission case cover by using the special tool.
Page 121 10. A.C. GENERATOR & STARTER CLUTCH Downtown 125i A.C. Generator & Starter Clutch Alternator Stator .......................... 4 1.1. Removal ..........................4 1.2. Inspection ......................... 5 1.3. Installation ........................5 Starter Clutch ..........................6 2.1. Removal ..........................6 2.2. Inspection ......................... 7 2.3.
Page 122: Generator & Starter Clutch Downtown 125I
10. A.C. GENERATOR & STARTER CLUTCH Downtown 125i SCHEMATIC DRAWING 10-2...
Page 123 10. A.C. GENERATOR & STARTER CLUTCH Downtown 125i SERVICE INFORMATION GENERAL INSTRUCTIONS  All servicing operations and inspections in this section can be made with the engine installed.  Drain the coolant before removing the right crankcase cover.  Be careful not to drain the coolant when the engine temperature is high. (Perform this operation when the engine is cold.) ...
Page 124: Alternator Stator
10. A.C. GENERATOR & STARTER CLUTCH Downtown 125i 1. Alternator Stator 1.1. Removal Drain the engine oil. Disconnect the alternator stator connectors. Remove the 10 bolts from the right crankcase cover and then remove the cover. Remove the two dowel pins and gasket. Remove the two pulse coil mount screws.
Page 125: Inspection
10. A.C. GENERATOR & STARTER CLUTCH Downtown 125i 1.2. Inspection Check the stator and pulse coil for damage. 1.3. Installation Install the stator and tighten the stator mount bolts to the specified torque. Torque: 1 kgf-m Apply sealant to the grommet seating surface and install it to the cover groove properly.
Page 126: Starter Clutch
10. A.C. GENERATOR & STARTER CLUTCH Downtown 125i 2. Starter Clutch 2.1. Removal Remove the right crankcase cover. Hold the flywheel with a special tool and remove the flywheel nut. Special tool: Flywheel holder A120E00021 Remove the flywheel/driven gear by using the special tool.
Page 127: Inspection
10. A.C. GENERATOR & STARTER CLUTCH Downtown 125i Remove the starter driven gear. 2.2. Inspection Install the driven gear into the flywheel. Check the operation of the spring clutch by turning the driven gear. You should be able to turn the driven gear clockwise smoothly, but the gear should not turn counterclockwise.
Page 128: Installation
10. A.C. GENERATOR & STARTER CLUTCH Downtown 125i 2.3. Installation Install the starter driven gear onto the crankshaft. Apply oil to the starter reduction gear shaft. Install the starter reduction gear and shaft to the right crankcase. Install the flywheel onto the crankshaft by aligning the key on the crankshaft with the groove in the flywheel.
Page 129 11. Crank Case & Crank Shaft Crank Case & Crank Shaft Schematic Drawing ..................... 2 Service Information ..................... 3 General Instructions ..................3 2.1. Specifications ....................3 2.2. 2.3. Torque Values ....................3 Troubleshooting ....................3 2.4. Crankcase ........................4 Splitting ......................
Page 130: Crank Case & Crank Shaft
11. Crank Case & Crank Shaft 1. Schematic Drawing 11-2...
Page 131: Service Information
11. Crank Case & Crank Shaft 2. Service Information 2.1. General Instructions  This section covers crankcase separation to service the crankshaft. The engine must be removed for this operation.  When separating the crankcase, never use a driver to pry the crankcase mating surfaces apart forcedly to prevent damaging the mating surfaces.
Page 132: Crankcase
11. Crank Case & Crank Shaft 3. Crankcase SAFETY FIRST: Protective gloves and eyewear are recommended at this point. 3.1. Splitting Drain the engine oil and remove the strainer screen. See the Engine Oil topic for more information. Remove the engine. See the Engine Removal topic for more information. Remove the cylinder head cover.
Page 133 11. Crank Case & Crank Shaft Remove the cam chain tensioner slipper bolt. Remove the cam chain tensioner slipper and cam chain. Remove the two right crankcase attaching bolts. Remove the left crankcase bolts. Place the crankcase with the left crankcase down and remove the right crankcase from the left crankcase.
Page 134 11. Crank Case & Crank Shaft Remove the oil seal from the left crankcase. 11-6...
Page 135: Crankshaft Inspection
11. Crank Case & Crank Shaft 4. Crankshaft Inspection Measure the connecting rod big end side clearance. Service Limit: 0.6 mm Measure the connecting rod small end I.D. Service Limit: 14.06 mm Measure the crankshaft run-out. Service Limit: 0.1 mm Measure the crankshaft bearing play.
Page 136: Crankcase Assembly
11. Crank Case & Crank Shaft 5. Crankcase Assembly Clean off all gasket material from the crankcase mating surfaces.  Avoid damaging crankcase mating surfaces. Install a new oil seal into the left crankcase. Place the left crankcase down and install the crankshaft into the left crankcase.
Page 137 11. Crank Case & Crank Shaft Install and tighten the right and left crankcase attaching bolts. Torque: 1.0 kgf-m Install the cam chain. Install the cam chain tensioner slipper. Install and tighten the cam chain tensioner slipper bolt. Torque: 1.0kgf-m 11-9...
Page 138 12. COOLING SYSTEM Cooling System SCHEMATIC DRAWING ..................... 2 SERVICE INFORMATION ................... 2 2.1. General Instructions ..................2 2.2. Special Tool ...................... 2 2.3. Torque Values ....................2 2.4. Troubleshooting ....................3 2.5. Specifications ....................3 2.6. Coolant Gravity ....................4 2.7.
Page 139: Cooling System
12. COOLING SYSTEM 1. SCHEMATIC DRAWING 2. SERVICE INFORMATION 2.1. General Instructions  The water pump must be serviced after removing the engine. Other cooling system service can be done with the engine installed in the frame.  The engine must be cool before servicing the cooling system. ...
Page 140: Troubleshooting
12. COOLING SYSTEM 2.4. Troubleshooting Engine temperature too high  Faulty temperature gauge or thermo sensor  Faulty radiator cap  Faulty thermostat  Insufficient coolant  Passages blocked in hoses or water jacket  Clogged radiator fins  Passages blocked in radiator ...
Page 141: Coolant Gravity
-37°C -44.5°C Cautions for Using Coolant: Use coolant of specified mixing rate. (The mixing rate of 425cc KYMCO SIGMA coolant concentrate + 975cc distilled water is 30 %.) Do not mix coolant concentrate of different brands. Do not drink the coolant which is poisonous.
Page 142: Radiator Cap Inspection
12. COOLING SYSTEM 3. RADIATOR CAP INSPECTION SAFETY FIRST: Protective gloves and eyewear are recommended at this point.  Removing the radiator cap while the engine is hot can cause the coolant to spray out, seriously scalding you.  Allow the engine sufficient time to cool before handling or working on the cooling system components.
Page 143: Coolant Replacement
12. COOLING SYSTEM 4. COOLANT REPLACEMENT 4.1. Preparation  Antifreeze is highly toxic and can kill pets and animals if drank. Do not leave coolant where animals (including children!) can get to it.  The effectiveness of coolant decreases with the accumulation of rest or if there is a change in the mixing proportion during usage.
Page 144: Air Bleeding
12. COOLING SYSTEM Remove the screw (3) and reserve tank lid (4). Open the coolant reserve tank lid. Siphon the coolant out of the reserve tank with an appropriate suction device. If a suction device is unavailable remove the reserve tank and poor it out.
Page 145: Radiator
12. COOLING SYSTEM 5. RADIATOR 5.1. Removal Drain the coolant. Disconnect the siphon hose (1) and air bleed hose (2). Remove the nut (3). Loosen the hose bands, and then disconnect the output hose (4) (to the water pump), coolant filling hose (5) and input hose (6) (from the engine) from the radiator.
Page 146: Inspection
12. COOLING SYSTEM 5.2. Inspection Inspect the radiator fins for damage and clogging. To remove the fan, take out the three mounting bolts with a 10 mm socket. Clean out the fins with low pressure compressed air and water. Check the radiator for any bent or damaged fins.
Page 147: Water Pump
12. COOLING SYSTEM 6. WATER PUMP 6.1. Mechanical Seal (Water Water Pump Seal) Inspection Inspect the telltale hole for signs of mechanical seal coolant leakage. If the mechanical seal is leaking, remove the right crankcase cover and replace the mechanical seal. Right Crankcase Cover 6.2.
Page 148 12. COOLING SYSTEM Remove the four bolts and the water pump cover, gasket and 2 dowel pins. Bolts Water Pump Cover Remove the water pump impeller. Impeller (Left Hand Treads)  The impeller has left hand threads. Inspect the mechanical (water) seal and seal Seal Washer (Porcelain) washer for wear or damage.
Page 149: Water Pump Shaft Removal
12. COOLING SYSTEM 6.3. Water Pump Shaft Removal Disconnect the water hose from the right crankcase cover. Remove the 5 bolts attaching the water pump assembly. Remove the water pump assembly, gasket and dowel pins. Remove the water pump shaft clip and Water Pump Shaft water pump shaft Install the water pump shaft and shaft inner...
Page 150: Water Pump/Impeller Installation
12. COOLING SYSTEM 6.4. Water Pump/Impeller Seal Washer (Porcelain) Installation Mechanical Seal When the mechanical seal is replaced, a new seal washer must be installed to the impeller. Impeller Install the impeller onto the water pump Impeller (Left Hand Treads) shaft.
Page 151: Water Temperature Sensor
12. COOLING SYSTEM 7. WATER TEMPERATURE SENSOR 7.1. Removal Remove the luggage box. Drain the coolant. Disconnect the water temperature sensor connectors. Remove the water temperature sensor from thermostat. 7.2. Inspection Connect the water temperature sensor to Sensor the ohmmeter and dip it in oil contained in a pan which is placed on an electric heater.
Page 152: Installation
12. COOLING SYSTEM 7.3. Installation With thread lock applied to the threaded part, tighten the water temperature sensor. Torque: 0.8 kgf-m (8 N-m, 5.8 lbf-ft) Connect the sensor connectors. After the water temperature sensor has been installed, fill coolant and perform air bleeding 12-15...
Page 153: Thermostat
12. COOLING SYSTEM 8. THERMOSTAT 8.1. Removal Drain the coolant. Remove the luggage box. Disconnect the water hose (1) from the thermostat housing. Remove the mounting bolts (2) and the thermostat housing from the cylinder head. 8.2. Installation The installation sequence is the reverse of removal.
Page 154: Inspection
12. COOLING SYSTEM 8.4. Inspection Thermostat Suspend the thermostat in a pan of water over a burner and gradually raise the water Thermometer temperature to check its operation. Technical Data Begins to open 80 - 82°C (176 - 180°F) Full-open 90°C (198°F) Valve lift 3.5 mm (0.14 in) minimum...
Page 155 14. FRONT ASSEMBLY Front Assembly SCHEMATIC DRAWING ..................... 2 SERVICE INFORMATION ................... 4 2.1. GENERAL INSTRUCTIONS ................4 2.2. SPECIFICATIONS .................... 4 2.3. TORQUE VALUES.................... 4 2.4. SPECIAL TOOLS ....................5 2.5. TROUBLESHOOTING ..................5 Front Wheel ......................... 6 3.1. Removal ......................
Page 156: Front Assembly
14. FRONT ASSEMBLY 1. SCHEMATIC DRAWING 14-2...
Page 157 14. FRONT ASSEMBLY 14-3...
Page 158: Service Information
14. FRONT ASSEMBLY 2. SERVICE INFORMATION 2.1. GENERAL INSTRUCTIONS  Remove the motorcycle frame covers before removing the front wheel, steering handlebar, front shock absorber and front fork. Jack the motorcycle front wheel off the ground and be careful to prevent the motorcycle from falling down. ...
Page 159: Special Tools
14. FRONT ASSEMBLY 2.4. SPECIAL TOOLS Lock nut wrench A120F00002 Oil seal and bearing installer A120E00014 Bearing piller A120E00037 Lock nut wrench A120F00023 Bearing race remover A120F00009 Bearing race installer A120F00019 2.5. TROUBLESHOOTING Hard steering (heavy) Front wheel wobbling  Excessively tightened steering stem top ...
Page 160: Front Wheel
14. FRONT ASSEMBLY 3. Front Wheel 3.1. Removal Lift the front end of the vehicle with a suitable stand or jack so that the front wheel comes off of the ground. Loosen the front axle pinch bolt (2) with a 6 mm Allen.
Page 161: Disassembly
14. FRONT ASSEMBLY Wheel Rim Place the wheel on a truing stand and use a dial indicator to check if the rim is out of true. The specifications for the front and rear wheels are the same. Check for lateral wobble.
Page 162: Assembly
14. FRONT ASSEMBLY Remove the front wheel bearing by using the special tool. Special tool: Bearing puller: A120E00037 Remove the distance collar from wheel. 3.4. Assembly Heat the bearing area of the wheel with a heat gun, take the bearing out of the freezer and install it.
Page 163: Front Brake Fluid
14. FRONT ASSEMBLY 4. Front Brake Fluid 4.1. Check Brake fluid: Fluid leakage → Replace. Cracks/wear/damage → Brake hose: Replace. Apply the brake lever several times. Brake hose clamp: Loosen → Tighten 4.2. Fluid Replacement/Air  A contaminated brake disc or pad Bleeding reduces stopping...
Page 164: Brake Fluid Filling/Air Bleeding
14. FRONT ASSEMBLY Loosen the bleed valve and pump the brake lever. Stop operating the brake when no more fluid flows out of the bleed valve. 4.4. Brake Fluid Filling/Air Bleeding  Do not mix different types of fluid since they are not compatible. Fill the master cylinder with DOT 4 brake fluid to the upper level.
Page 165: Front Brake Pad
14. FRONT ASSEMBLY 5. Front Brake Pad 5.1. Brake Pad Replacement Remove the pad pins (1). Remove the two caliper mounting bolts (2), and then remove the caliper. Remove the brake pads. Replace the pads if the brake wear exceeds the wear indicator lines or if the wear is uneven.
Page 166: Brake Disc
14. FRONT ASSEMBLY 6. Brake Disc 6.1. Inspection Visually inspect the brake disc for damage or cracks. Measure the brake disc thickness. Service limits: 4 mm Replace the brake disc if the smallest measurement is less than the service limit. Measure the brake disc warpage.
Page 167: Handlebar
14. FRONT ASSEMBLY 7. Handlebar 7.1. Removal Remove the lower handlebar cover and front cover. Remove the 4 bolts and disconnect the brake light switch wire, then remove the front and rear brake master cylinder. Remove the inner cover Route the cables and lines from the handlebar cable guide.
Page 168: Disassembly
14. FRONT ASSEMBLY 7.3. Disassembly Switches Remove screws from right handlebar switch. Disconnect the throttle cables and free the right switch housing from the handlebar. Remove the two screws and then remove the left handlebar switch. Disconnect the switch. Separate the left switch housing from the handlebar.
Page 169: Assembly
14. FRONT ASSEMBLY If you plan to replace the grips you can slice them lengthwise with a razor blade and peel them off. To remove the grips without cutting them use a screwdriver to open a gap between the grip and the handlebar. Spray in contact cleaner to break up the grip cement.
Page 170: Front Shock Absorber
14. FRONT ASSEMBLY 8. Front Shock Absorber 8.1. Removal Remove the front cover and front fender. Remove the front brake caliper. Remove the front wheel. Remove the speed wheel sensor bolt (1). Remove the speed sensor wire and front brake hose guide mounting bolt with an 8 mm socket.
Page 171: Steering Stem
14. FRONT ASSEMBLY 9. Steering Stem 9.1. Removal Support the vehicle with a suitable stand or jack so that the front wheel is off the ground. Grip the bottom of the fork legs and turn the front end side-to-side. If the movement is rough the bearings should be greased or replaced.
Page 172 14. FRONT ASSEMBLY Inspect the ball races, cone races and steel balls for wear or damage. Replace if necessary. Remove the top balls. Remove the bottom balls. Use the special tools or a drift and hammer to drive out the bearing races in the steering head.
Page 173: Installation
14. FRONT ASSEMBLY 9.2. Installation Install the new bottom cone race onto the steering stem. Install the new upper and bottom ball races into the frame. Apply grease to the top and bottom ball races and install new steel balls on the top ball race and new steel balls on the bottom ball race.
Page 174 14. FRONT ASSEMBLY Bottom Ball Race Remove Special Tool Bottom Ball Race Top Ball Cone Race Install special tool Install special tool 14-20...
Page 175 15. REAR ASSEMBLY Rear Assembly SCHEMATIC DRAWING ..................... 2 SERVICE INFORMATION ................... 3 2.1. General Instructions ..................3 2.2. Specifications ....................3 2.3. Torque Values ....................3 2.4. Troubleshooting ....................4 Rear Brake ........................5 3.1. Rear Brake Caliper Removal ................5 3.2.
Page 176: Schematic Drawing
15. REAR ASSEMBLY 1. SCHEMATIC DRAWING 15-2...
Page 177: Service Information
15. REAR ASSEMBLY 2. SERVICE INFORMATION 2.1. General Instructions  When performing the services stated in this section, the engine and exhaust muffler must be cold to avoid scalding.  During servicing, keep oil or grease off the brake pads and brake disk. 2.2.
Page 178: Troubleshooting
15. REAR ASSEMBLY 2.4. Troubleshooting Rear wheel wobbling  Bent rim  Faulty tire  Axle not tightened properly  Engine not tightened properly  Tire pressure too low  Unbalanced wheel Soft suspension  Weak shock absorber spring  Damper oil leaks Hard suspension ...
Page 179: Rear Brake
15. REAR ASSEMBLY 3. Rear Brake 3.1. Rear Brake Caliper Removal Drain the rear brake fluid. Place a suitable container under the banjo bolt to catch any remaining brake fluid. Remove the banjo bolt that holds the brake hose. Discard the two sealing washers. Replace the brake hose banjo bolt sealing washers with new items on assembly.
Page 180: Disassembly
15. REAR ASSEMBLY 3.3. Disassembly Remove two brake pads dowel pins and three bolts from the brake caliper. Remove the brake pads. Remove the piston from the brake caliper. If necessary, use compressed air to squeeze out the piston through the brake fluid inlet opening and place a towel under the caliper to avoid contamination caused by the removed piston.
Page 181: Assembly
15. REAR ASSEMBLY 3.4. Assembly Clean all removed parts. Apply silicon grease to the piston and oil seal. Lubricate the brake caliper cylinder inside wall with brake fluid. Install the brake caliper piston with grooved side facing out.  Install the piston with its outer end protruding 3 ~ 5mm beyond the brake caliper.
Page 182: Installation
15. REAR ASSEMBLY 3.5. Installation Install the brake caliper to the rear fork and tighten the two bolts. Torque: 35 N-m Connect the brake fluid tube to the brake caliper and install fluid tube bolt, copper washers and tighten the fluid tube bolt. Fill the brake reservoir with the specified brake fluid and bleed air from the brake system.
Page 183: Rear Fork
15. REAR ASSEMBLY 4. Rear Fork 4.1. Removal Lower bolt Speed sensor Place the vehicle on its center stand. Remove the exhaust muffler. Remove the rear brake caliper. Remove the speed sensor. Remove the speed sensor wire and the rear brake fluid hose holder.
Page 184: Rear Wheel
15. REAR ASSEMBLY 5. Rear Wheel 5.1. Removal Remove the exhaust muffler. Remove the rear brake caliper. Remove the rear fork. Remove the rear axle collar. Remove the rear wheel. 5.2. Inspection Measure the rear wheel rim runout. 5.3. Installation Rear axle Apply a proper amount of grease on the rear axle before installation.
Page 185: Rear Shock Absorber
15. REAR ASSEMBLY 6. Rear Shock Absorber 6.1. Removal Remove the met-in box and carrier. Remove the body cover, center cover and rear fender together. Remove the right/left rear shock absorber upper and lower mount bolts. Remove the right and left rear shock absorbers.
Page 186 16. BATTERY/CHARGING SYSTEM Battery/Charging System CHARGING SYSTEM LAYOUT ......................2 SERVICE INFORMATION ........................ 3 2.1. GENERAL INSTRUCTIONS ....................3 2.2. SPECIFICATIONS ........................ 4 2.3. TROUBLESHOOTING ......................4 Battery ............................5 3.1. Removal ..........................5 3.2. Installation ........................5 3.3. Voltage Inspection ......................5 3.4.
Page 187: Charging System Layout
16. BATTERY/CHARGING SYSTEM 1. CHARGING SYSTEM LAYOUT Negative cord Positive cord OBD connector REGULATOR/RECTIFIER 16-2...
Page 188: Service Information
16. BATTERY/CHARGING SYSTEM 2. SERVICE INFORMATION 2.1. GENERAL INSTRUCTIONS  The battery can be charged and discharged repeatedly. If a discharged battery is not used for a long time, its service life will be shortened. Generally, the capacity of a battery will decrease after it is used for 2～3 years.
Page 189: Specifications
16. BATTERY/CHARGING SYSTEM 2.2. SPECIFICATIONS Item Standard Capacity 12V 8Ah Fully charged 13.0~13.2V Voltage (20℃) Battery Undercharged 12.3V Normal 1.0*5~10H Charging current Quick 10A*0.5H Capacity 240W/5000rpm Charging coil resistance (20℃) Yellow-Yellow Alternator RPM of charging start Under 1300prm (14V) Charging performance 18A/ 5000rpm 14.5±0.5V Regulator/ Rectifier...
Page 190: Battery
16. BATTERY/CHARGING SYSTEM 3. Battery 3.1. Removal Positive cable Negative cable The battery is in the front part of the vehicle. 1. Remove the wind screen and front cover. 2. Remove the screws. 3. Remove the battery cover. 4. Disconnect the negative cable from the battery first, and then disconnect the positive cable.
Page 191: Battery Charging
16. BATTERY/CHARGING SYSTEM 3.4. Battery Charging Remove the battery Connect the charger positive (+) cable to the battery positive (+) terminal. Connect the charger negative (-) cable to the battery negative (-) terminal.  Clean the battery terminals and position the battery as far as away from the charger as the leads will permit.
Page 192: Charging System Inspection
16. BATTERY/CHARGING SYSTEM 4. Charging System Inspection 4.1. Charging Voltage Positive terminal Negative terminal  Perform this inspection after the battery is fully charged. Start the engine and warm it up to the operating temperature; stop the engine. Connect multimeter between positive and negative terminals of the battery.
Page 193: Regulator/Rectifier
16. BATTERY/CHARGING SYSTEM 5. Regulator/Rectifier 5.1. Inspection Disconnect regulator/rectifier connectors. Check the connectors for loose contacts of corroded terminals. Battery line Measure voltage between Red/White wire terminal and ground. There should be battery voltage at all times. Ground line Check the continuity between the Green wire terminal and ground.
Page 194: Removal/Installation
16. BATTERY/CHARGING SYSTEM 5.2. Removal/Installation Regulator /rectifier Remove the side body cover Disconnect regulator/rectifier connectors. Remove the two bolts, regulator/rectifier. Installation is in the reverse order of removal. 16-9...
Page 195 18. STARTING SYSTEM Starting System Starting System Layout ....................2 Service Information ..................... 3 2.1. General Instructions ..................3 2.2. Torque Values ....................3 2.3. Troubleshooting ....................3 Start Motor ........................4 3.1. Inspection ......................4 3.2. Removal ......................4 3.3.
Page 196: Starting System Layout
18. STARTING SYSTEM 1. Starting System Layout Start Relay Battery Start Motor 18-2...
Page 197: Service Information
18. STARTING SYSTEM 2. Service Information 2.1. General Instructions  The removal of starter motor can be accomplished with the engine installed.  For the starter clutch removal, refer to the chapter 10.  After the starter clutch is installed, be sure to add the engine oil and coolant and then bleed air from the cooling system.
Page 198: Start Motor
18. STARTING SYSTEM 3. Start Motor 3.1. Inspection Connect the start motor cable directly to the battery positive terminal. If the start motor does not turn, the starter motor is faulty. 3.2. Removal Rubber cap Cable Turn the ignition switch turned to “OFF” Release the rubber cap and remove the terminal screw to disconnect the cable from the start motor.
Page 199: Starter Relay
18. STARTING SYSTEM 4. Starter Relay 4.1. Removal Disconnect the starter relay wire connector. Release the rubber caps and remove the nuts, then disconnect the start motor cable, battery positive cable and harness wire. Remove the starter relay. 4.2. Installation Install the starter relay.
Page 200 18. STARTING SYSTEM Starter Relay Voltage Turn on the ignition switch. Use a multimeter to measure the voltage. One probe touch the Y/R wire the other touch the ground. The measurement result will be close to the battery voltage Grounding Circuit Disconnect the connector.
Page 201 19. ELECTRICAL SYSTEM Electrical System SERVICE INFORMATION ................... 3 1.1. GENERAL INSTRUCTIONS ................3 1.2. Specification ..................... 3 1.3. Troubleshooting ....................3 Front Lights assy ......................4 2.1. Headlight ......................4 2.2. Front turn signal lights..................4 Rear Lights assy......................5 3.1.
Page 202 19. ELECTRICAL SYSTEM 10.1. Inspection ....................18 10.2. Removal/Installation ..................18 11. Rollover sensor ......................19 11.1. Inspection ....................19 11.2. Removal/Installation ..................19 19-2...
Page 203 19. ELECTRICAL SYSTEM 1. SERVICE INFORMATION 1.1. GENERAL INSTRUCTIONS  Note the following when replacing the halogen headlight bulb  Wear clean gloves while replacing the bulb. Do not put finger prints on the headlight bulb, as they may create hot spots on the bulb and cause it to fail. ...
Page 204 19. ELECTRICAL SYSTEM 2. Front Lights assy 2.1. Headlight  Place a cloth under the headlight assy after removal prevent scratches. Remove the headlight assy. Remove screws. Remove the headlight. Install in the reverse order of work. 2.2. Front turn signal lights Remove the headlight assy.
Page 205 19. ELECTRICAL SYSTEM 3. Rear Lights assy 3.1. Tail light assy Remove the rear light assy. Remove screws on the each side of cover. Remove the side covers. Remove the rear center cover. Remove the screws. Remove the tail light assy. Installation is in the reverse order of removal.
Page 206 19. ELECTRICAL SYSTEM 3.2. License Plate Light Remove the rear light assy. Remove the screws. Remove the license plate light. Remove the screws. Push and turn the bulb counterclockwise to remove it, and then replace with a new one. Specification: 12V 5W Installation is in the reverse order of removal.
Page 207 19. ELECTRICAL SYSTEM Rear Speed Sensor Remove the right side cover, Disconnect the speed sensor connector. Remove the bolt. Remove the rear speed sensor. Install in the reverse order of removal. 4.2. Inspection After remove the speed sensor, rotate the wheel to check the speed sensor ring.
Page 208 19. ELECTRICAL SYSTEM 5. Switches 5.1. Brake Light Switch Remove the upper handlebar cover. Disconnect front rear light switch connectors and check for continuity between the switch terminals (1). There should be continuity with the front or rear brake lever squeezed, and there should be no continuity when the front or rear brake lever (2) is released.
Page 209 19. ELECTRICAL SYSTEM 5.3. Right handlebar switch Disconnect the right handlebar switch connector and check for continuity at switch side connector terminals. Continuity should exist between the color code wires as follows: Engine Stop SW Engine stop switch BAT3 COLOR 19-9...
Page 210 19. ELECTRICAL SYSTEM 5.4. Left Handlebar Switch Disconnect the left handlebar switch Turn Signal Light Switch connector and check for continuity at switch side connector terminals. Continuity should exist between the color code wires as follows: Horn Switch Passing Switch Dimmer switch 19-10...
Page 211 19. ELECTRICAL SYSTEM 6. Luggage Box Light Sensor 6.1. INSPECTION Remove the luggage box. Disconnect the luggage box light sensor connector and check the luggage box light sensor for continuity between the sensor terminals. There should be no continuity with the luggage box light sensor being covered up, and there should be continuity with the luggage box light sensor being not covered...
Page 212 19. ELECTRICAL SYSTEM 7. Oil pressure sensor 7.1. Inspection Check the engine oil level is at the standard before inspection. The engine oil pressure will maintain in a certain pressure after start the engine. To inspect the oil pressure sensor, the ignition switch should be turned on.
Page 213 19. ELECTRICAL SYSTEM 7.2. Removal Remove the protective cap and disconnect the wire. Remove the engine oil pressure sensor. 7.3. Installation 3~4mm Apply suitable sealant as shown and do not seize the sensor. Tighten the oil pressure sensor to specified torque.
Page 214 19. ELECTRICAL SYSTEM 8. Fuel Pump 8.1. Removal Remove the seat. Remove the center cover Remove the fuel pump connector Be sure to relieve the fuel pressure before removing fuel pump or fuel hose. Remove the 6 nuts (1) and fuel unit connectors(2) then remove...
Page 215 19. ELECTRICAL SYSTEM 8.2. Inspection Connect the fuel unit wire connectors and turn the ignition switch “ON”.  Before performing the following test, operate the turn signals to determine that the battery circuit is normal.  Use a good condition and fully charged battery to perform the inspection.
Page 216 19. ELECTRICAL SYSTEM Measure the resistance between the Yellow/White and Blue/White terminals of the fuel unit connector. Standard (at 20°C/68°F): About1100 Ω Float at full position Float at empty position About100 Ω 8.3. Installation Installation is in the reverse order of removal.
Page 217 19. ELECTRICAL SYSTEM 9. Side Stand Switch 9.1. Inspection Disconnect the side stand switch connector (1). There should be continuity between the Yellow/Green and Green with the side stand retracted. There should be continuity between the Yellow/Black and Green with the side stand applied.
Page 218 19. ELECTRICAL SYSTEM Horn 10.1. Inspection Remove the front cover. Disconnect the horn connectors (1) from the horn. Connect a 12 V battery to the horn terminals. The horn is normal if it sounds when the 12 V battery is connected across the horn terminals.
Page 219 19. ELECTRICAL SYSTEM Rollover sensor 11.1. Inspection Place the vehicle on a level ground and on its center stand. Remove the front cover. Turn on theignition switch. Use probes of a multimeter to test the voltage of the rollover sensor. Termials Standard Rollover sensor...
Page 220 3.5. DTC Cleared ........................12 3.6. Data Analyze ........................12 3.7. Air Bleeding ........................12 DTC List ............................13 4.1. Bosch ABS91 DTC List ..................... 13 TCS DTC List .................錯誤! 尚未定義書籤。 4.2. Introduction to KYMCO TCS System ............錯誤! 尚未定義書籤。 20-1...
Page 221: Abs
20. ANTI-LOCK BRAKE SYSTEM (ABS) 1. ABS 1.1. Indicator Light The ABS indicator light in the meter position. This light will comes on when the ignition switch is turned on and goes off shortly after the vehicle starts moving at speed 6km/hr. min. It stays off.
Page 222 20. ANTI-LOCK BRAKE SYSTEM (ABS) ˙ ABS will help prevent wheel lock-up when braking in straight line but it cannot control wheel slip, which may be caused by braking during cornering. When turning a corner, it is better to limit braking to the light application of both brakes or not to brake at all. Reduce your speed before you get into the corner.
Page 223: Troubleshooting Outline
20. ANTI-LOCK BRAKE SYSTEM (ABS) 1.3. Troubleshooting Outline The ABS indicator light lights up to alert the rider when an abnormality is detected by the system. The service codes are stored in the ABS unit memory. The codes will not be erased unless manually cleared.
Page 224 20. ANTI-LOCK BRAKE SYSTEM (ABS) Pre-diagnosis Inspection Chart 1 20-5...
Page 225 20. ANTI-LOCK BRAKE SYSTEM (ABS) Pre-diagnosis Inspection Chart 2 20-6...
Page 226: Removal
20. ANTI-LOCK BRAKE SYSTEM (ABS) 1.4. Removal Rear brake Front brake  When replacing a new Hydraulic fluid output fluid output Unit, don’t need to drain the brake fluid. Place a cloth under the ABS module. Remove the input and output bolts. Rear brake Front brake...
Page 227: Diagnostic Tool
20. ANTI-LOCK BRAKE SYSTEM (ABS) 2. Diagnostic Tool 2.1. PC version Open the diagnostic tool software. Remove the front cover. Connect the integrated linker to the OBD connector. Turn on the ignition switch. OBD connector Chose the ABS brake system. Check the ECU version.
Page 228: Diagnostic Tool Operation
20. ANTI-LOCK BRAKE SYSTEM (ABS) 3. Diagnostic Tool Operation 3.1. Operation Instructions Part No. 3620A-LEB2-E00 AHG1 ECU Version DTC Inspect DATA Analyze Adjust KEY FUNCTION ① Model No. ⑥ UP Button ② Down Button ⑦ Adjust (TPI and ABV reset function) ③...
Page 229: Connection
3.2. Connection Connect the sub cord to the OBD connector then connect KYMCO Fi diagnostic tool. (KYMCO Fi Diagnostic tool Power comes from vehicle’s Battery) OBD Connector Put the side stand upward and ENG. stop switch is at “RUN” position.
Page 230: Dtc Inspect
20. ANTI-LOCK BRAKE SYSTEM (ABS) 3.3. DTC Inspect ABS91 Choose DTC Inspect Load DTC (Active 、Occurred、History) 3.4. DTC Displayed 1. Rear wheel speed sensor disconnect 2. Front wheel speed sensor disconnect 20-11...
Page 231: Dtc Cleared
20. ANTI-LOCK BRAKE SYSTEM (ABS) 3.5. DTC Cleared 1. Choose “Clear DTC” and then push “Enter” button. 2. Clearing DTC completed until the DTC red lamp is off. 3.6. Data Analyze ABS91 Choose “DATA Analyze” and then push “Enter” button Front wheel speed &...
Page 232: Dtc List
20. ANTI-LOCK BRAKE SYSTEM (ABS) 4. DTC List Bosch ABS91 DTC List 4.1. Code NO DTC Code Description 5013 Rear Inlet Valve malfunction (EV) 5014 Rear Outlet Valve malfunction (AV) 5017 Front Inlet Valve malfunction (EV) 5018 Front Outlet Valve malfunction (AV) 5019 Valve Relay malfunction (Failsafe relay) 5025...
Page 233 21. EEC SYSTEM EEC System Diagram ........................2 1.1. Evaporates Emission Control System Diagram ..........2 1.2. Pollution Emission System Diagram .............. 2 E.E.C System Introduction ..................3 2.1. Evaporative Emission Control System ............3 2.2. Crankcase Emission Control System ............. 3 2.3.
Page 234: Diagram
21. EEC SYSTEM 1. Diagram 1.1. Evaporates Emission Control System Diagram Negative pressure Fuel injector Fuel Fuel Air cleaner pump Canister Fuel vapors Water Fuel tank bleed hole atmosphere Negative pressure Fuel Fuel vapors 1.2. Pollution Emission System Diagram Fuel vapors Intake Throttle body manifold...
Page 235: System Introduction
21. EEC SYSTEM 2. E.E.C System Introduction WARNING: • Before running the engine, make sure that the working area is well ventilated. Never run the engine in a closed area. The exhaust contains poisonous carbon monoxide gas, which may cause death to people. •...
Page 236: Function
21. EEC SYSTEM 3. Function Item Function Description It is used to prevent gasoline Evaporative Storage the gasoline vapors to canister, vapors from escaping into the Emission conduct the gasoline vapors to engine atmosphere from the fuel tank Control Valve by vacuum when starting the engine.
Page 237: Maintenance Schedule
21. EEC SYSTEM 4. Maintenance Schedule Perform the pre-ride inspection at each scheduled maintenance period. This interval should be judged by odometer reading or months, whichever comes first. I: INSPECT AND CLEAN, ADJUST, LUBRICATE OR REPLACE IF NECESSARY C: CLEAN R: REPLACE T: Tighten M: Maintain D: Diagnostic Maintenance Operation Item Maintenance Interval Mileage 300 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000 12000...
Page 238 5000 km. Replace the sensor when necessary. 4.2. Notes 1. We recommend that you add a bottle of KYMCO fuel injector cleaner every 1000 km to the fuel tank. 2. An air blow gun must be used to clean the dust and foreign objects inside the belt wheel for models with rear wheel driving belt.
Page 239: Maintenance Information
21. EEC SYSTEM 5. Maintenance Information Note of maintenance: • Flame or spark should keep away when performing maintenance. • Install the tubes in correct position. • If the tubes broken should be replaced with a new one. • The tubes should be installed tightly. •...
Page 240: Canister
21. EEC SYSTEM 6. Canister 6.1. Removal 1. Remove the windshield, front cover and head light assembly. 2. Remove the canister tube set and canister. Canister 6.2. Inspection Canister Evaporative Control Valve Connect a vacuum pump to the tube of canister.
Page 241: Installation Of Canister
21. EEC SYSTEM Flow Rate of the Canister Vacuum Valve 1. Using a vacuum pump connecting to the vacuum tube of canister and apply 45m/mHg negative pressure. 2. Apply pressure to the emission control valve of canister, if the flow rate above 9.4 liters per minute that means the valve is in good condition, otherwise the canister...
Page 242: Inspection
Air filter cover cleaner element. The new air cleaner element installation is in the reverse order of removal. Use the KYMCO genuine air cleaner element or an equivalent air cleaner element specified for your model. Using the wrong KYMCO cleaner...
Page 243: Inspection Of Emission System
21. EEC SYSTEM 7.3. Inspection of emission system Inspect the air cleaner. Inspect the spark plug. Inspect the ignition system. Plug in the diagnostic tool the check the information. Warm up the engine reach above 80°C. This model equipped the catalyst in the muffler to reduce the pollution emission.
Page 244: Oxygen Sensor
21. EEC SYSTEM 8. Oxygen Sensor It uses DC-8-16V Battery Power with 4 pins: one power pin, one heater pin, one signal output pin and one earthing pin. The sensor is installed to the front pipe of exhaust pipe to detect the oxygen concentration of exhaust gas for determining if ECU shall instruct to increase or reduce fuel supply for meeting waste gas emission standard of environment legislation.

KYMCO AHG1 Maintenance Manuallines

1. Quick Reference 1

2. External Components, Exhaust Pipe

3. Periodic Maintenance

4. Lubrication System

6. Cylinder Head/ Valve

7. Cylinder/ Piston

8. Drive & Driven Pulleys

9. Final Reduction

Table of Contents

Crank Case & Crank Shaft

12. Cooling System

14. Front Assembly

15. Rear Assembly

Quick Links

Chapters

Troubleshooting

Related Manuals for KYMCO AHG1

Summary of Contents for KYMCO AHG1