Worx 125 Service Manual Holtvej 8-10, Høruphav, 6470 Sydals Telefon: +45 73 15 11 00 Fax: +45 73 15 11 01 E-mail: info@scanmi.dk · www.scanmi.
Two-wheel Motorcycle QJ125-26A Instruction and Maintenance Manual ZHEJIANG QIANJIANG MOTORCYCLE CO., LTD.
Contents Contents .......................................................................................................................................................................... 2 Preface ............................................................................................................................................................................ 5 Preparatory Data .........................................................................................................................
7.1 Preparatory Data ............................................................................................................................................. 97 7.2 Fault Diagnosis ............................................................................................................................................... 97 7.3 Front Wheel .................................................................................................................................................... 98 7.
14.4 Disassemble Main Shaft and Countershaft ................................................................................................. 148 XV Reduction Gear ................................................................................................................................................... 151 15.1 Preparatory Data ......................................................................................................................................... 151 15.2 Fault Diagnosis ..........
Preface The Instruction and Maintenance Manual contains an introductory description of maintenance on QJ 125-26A motorcycle. Preparatory data include attentions that shall be paid on all the maintenance operations in the Instruction and Maintenance Manual. Please read the manual carefully before operation. Inspection and adjustment contains main aspects for inspection and adjustment, safety of the vehicle, performance and maintenance of each component.
Preparatory Data General Safety Maintenance Rules Specification Table Fault Diagnosis General Safety Carbon monoxide (CO) When it is necessary to start the engine, please make sure the operation area is well ventilated. Never run the engine in an enclosed place. Attention Gas exhausted from the motorcycle contains harmful carbon monoxide, which may lead to loss of consciousness and death. It is necessary to run the engine in an open area.
Maintenance Rules While repairing and servicing, use tools of metric system as possible. Incorrect tools may damage the motorcycle. Before taking down or opening protecting plate for repair work, please clean the dirt on the external surfaces of components or combination parts and prevent the dirt from falling into engine, chassis or braking system After disassembly and before measuring friction, please clean the components and blow them with compressed air.
Length of bolts and screws are different for assembly components and protecting plates. They shall be installed at correct positions. If confused, just put the bolt in the hole and see if it matches. Fill lubricating grease into the groove during oil seal installation. Check if the oil seal is smooth and if there is any damage to it. Installation of rubber hose (fuel, vacuum, or coolant): insert its end into bottom of connector so that there is enough room for the hose clamp to grip the connector.
Slack cable implies potential safety hazard on electrics.
Identification of motorcycle 1. Frame number ① labeled as: *LBBJ8300?????????*,,as shown in Figure 1-1. Figure 1-1 MODEL QJ150 DISPLACEMENT 150CC PRODUCTION D.T. ZHEJIANG QIANJIANG MOTORCYCLE CO., LTD 2. Frame nameplate is riveted at frame Position ②, as shown in Figure 1-1. Words on the nameplate are as described in Figure 1-2. Figure 1-2 3. Serial number of engine ① is marked on the housing of crankcase, as shown in Figure 1-3. Figure 1-3 Important Notice 1.
Special Tools Special tools are known as specially designed tools used at particular places for assembly or disassembly of certain components on a motorcycle. Suitable special tools are essential for complete and accurate adjusting and assembling work. Use of special tools can realize safe, reliable and quick disassembly or assembly of components, as well as working efficiency improvement and labor saving.
Figure 1-5 Figure 1-6 Figure 1-7 Figure 1-8 Figure 1-9 Figure 1-10 ① Handle Figure 1-11 Figure 1-12 ① Pliers ② Piston
Figure 1-13 Figure 1-14 Figure 1-15 Figure 1-16 Figure 1-17 Figure 1-18 Figure 1-19 Figure 1-20 Figure 1-21 Figure 1-22
Figure 1-23 Figure 1-24 2．Tools used for chassis overhaul Common and special tools, as well as their pictures for chassis component assembly and disassembly are listed in Table 1-25 and Table 1-26.
Figure 1-31 Figure 1-32 Figure 1-33 Figure 1-34 Figure 1-35 Figure 1-36 （2）Special tools for chassis overhaul: Front fork seal driver Figure 1-37 （3）Steering nut wrench Figure 1-38
3．Tools used for electrical components Special tools and their pictures for electrical component measurement are listed in Table 1-39 and Table 1-40.
Specifications (QJ125-26A) Model QJ125-26A Engine type QJ157FMI-2B 90# or higher unleaded gasoline 2040mm Fuel type Overall Width 780mm Number cylinders Overall height 1,050mm Bore*stroke 57.0×48.
Fault Diagnosis Symptom: Engine will not start or is hard to start Diagnosis procedures Engine will not start or is hard to start Check ignition system Remove the spark plug and check if electrodes of the plus are connected by carbon. No Yes Perform spark-over test Clean deposited carbon Spark is weak between electrodes or no spark at all.
1. Remove spark plug and check. Check leakage at 1. Check if breather on external connection parts the fuel tank cap is of engine; 2.Check valve clogged; 2. Check if timing; fuel 3. Check filter and fuel tightness between valve switch are clogged; 3. and valve seat; 4. Check Check if fuel switch if valve clearance is too works small; 5.Check if piston Check if oil intake of ring is stuck inside the carburetor is clogged; ring groove or of less 5.
Symptom: Engine Overheats Diagnosis procedures Engine Overheats Check improper operation method Yes No 1. Check if gasoline brand being used is too Check cooling system low or the gasoline has been stored for a too long time; 2.
Clutch slips Remove the spark plug and check color of skirt section of insulating part and Handle it according to other abnormalities to judge mixture ratio of air/fuel. Item 1.7. Skirt section of insulating part is black and when the Skirt section of insulating part is Skirt section of insulating part is brown.
Symptom: Engine lacks power Diagnosis procedures Engine lacks power Lift it with main stand to have the wheels off the ground. Rotate wheels by hands. Wheels rotate freely. Wheels rotate inflexibly. Check tire pressure 1. Check braking drag; 2. Check if bearing of wheels are over worn or injured; 3. Check if the middle spacers in Air pressure too low the hub are missed or short.
Symptom: Poor idle speed of engine Diagnosis procedures Poor idle speed Engine has no idle speed. Check compression pressure in cylinder Higher idle speed Pull throttle valve of carburetor by hand Use an ignition timing lamp to and see if it is completely closed. check ignition timing of engine Yes Insufficient compression Y No N Compression pressure pressure in cylinder in cylinder is normal.
Symptom: Too much fuel consumption by the engine Diagnosis procedures Too much fuel consumption Check operation method Yes No Lift it by main stand, rotate wheels by hands 1. Check if motorcycle is driven over speed or not at economical speed or driven at low gear; 2. 1. Check Check if gasoline grade being Wheels rotate freely. Wheels rotate inflexibly. braking used is correct. Check tire pressure drag; 2. Check if bearings of wheels are over worn or Air pressure too low injured; 3.
Symptom: Clutch slips Diagnosis procedures Clutch slips Manually controlled wet multi-plate clutch slips Automatic centrifugal dry type shoe clutch slips Check if braking shoe of shoe-type clutch is contaminated by oil Check if clearance of clutch handle bar is within 10mm~20mm. No No Yes Check if throttle cable can pull Re-adjust flexibly in the cable jacket. Check if braking shoe Clean is excessively worn. dirt No No Check if engine oil level in replace the crankcase is too low.
Symptom: 4-stroke engine exhaust muffler gives off blue-white smoke Diagnosis procedures 4-stroke engine exhaust muffler gives off blue-white smoke Check if engine oil level in the crankcase exceeds the upper limit line Yes No Too much engine oil in the crankcase, bleed surplus oil Start engine and run it at high speed; screw off and decline oil level to upper limit line. oil ruler and check if oil filler smokes. No Yes Check if clearance between valve 1.
Symptom: Difficult gearshift on transmission Diagnosis procedures Difficult gearshift on transmission Start engine and check if idle is too high. No Yes Re-adjust Check if the operation is harmonious at gearshift. Yes No Check if clutch is completely separated. No Improve operation method. Yes Check if gearshift box is distorted and shift lever is deformed or over worn. No 1. Check if clearance of clutch handle bar is within 10mm~20mm; 2. Check if elasticity of Yes clutch spring is even; 3.
Symptom: Transmission jumps of gear Diagnosis procedures Transmission jumps of gear Check if spring of position wheel is broken or of insufficient elasticity. Yes Replace No Disassemble crankcase and check if meshing depth of each gear meets requirement. Enough meshing depth Insufficient meshing depth Check if meshing end of cam pawl on end face of meshing gear is worn or Check if shift fork is over worn or distorted.
Symptom: Battery cannot charge Diagnosis procedures Battery cannot charge Disconnect connectors of magneto lead wire tied to the cables of the whole motorcycle. Measure with an Ohmmeter between out-put wires from charging coil Resistance is less than standard. Resistance meets the standard. Resistance is infinitely great. Connect connectors of magneto lead wire harness to the Charging coil is shorted.
Symptom: Battery runs down quickly Diagnosis procedures Battery runs down quickly Check if braking lamp is always on. Yes No Adjust or replace braking Set ignition switch to “OFF” position, disconnect negative wire from battery, and then put lamp switch. negative probe of ammeter onto the negative pole terminal and positive probe on the negative wire to check current leakage. Leaking current is smaller than specified. Leaking current is bigger than specified（usually It shall be no more than 1mA.
Symptom: Starting motor does not run Diagnosis procedures Starter motor does not run. Turn on ignition switch; press horn button or slide turn signal lamp switch. Electric horn does not sound or sound Electric horn sounds weakly. Turn signal lamp is dim. Turn signal lamp is bright. loudly. Battery is low or the wire terminal Grasp brake handle bar (autoscooter), or shift connected with battery is poorly transmission into neutral, or grasp clutch handle contacted. bar, push starter button.
Coil in starter coil Check wiring is electrical starter broken or shorted. inside Contact control Autoscooter Grasp brake handle and check if braking lamp is on. Yes Inner contact of brake lamp switch is is poorly contacted poor contacted or its wire is broken. replace starter button. No Check if starter button contact Yes or 1. Check if the carbon brush is over worn; 2. Check if carbon brush spring is broken or weak. 3. Check if armature commutator is over worn. 4.
Symptom: Starting motor runs weakly Diagnosis procedures Starting motor runs weakly. Turn on ignition switch; press horn button or slide turn signal lamp switch. Electric horn does not sound or sound Electric horn sounds loudly. weakly. Turn signal lamp is bright. Battery is low or the lead wire Check if the lead wire connector from starter relay connector connected with battery is to starter motor is poorly contacted. badly contacted.
Symptom: All the lights are not on Diagnosis procedures All the lights are not on AC power supplied lighting system DC power supplied lighting system Separate conductors of lead wire bundle of magneto from the cables of the whole vehicle. Check if there is power output from lighting coil Press horn button or slide turn signal light. of magneto with lamp test method. Test lamp is not lit Test lamp is lit.
Yes No Replace headlamp bulb and Check if there is power output from power check other bulbs one by one. input wire of light switch by lamp test Yes Use a piece of wire to short circuit power line and output line of lighting switch. No Wiring from magneto or ignition switch to lighting switch is broken or shorted. Lamp is lit after short circuit. Inner contact of lighting switch is poorly contacted. Lamp is still not lit after short circuit.
Symptom: Light bulb is burnt frequently Diagnosis procedures Light bulb is burnt frequently Turn on ignition switch; press horn button or slide turn signal lamp switch. Electric horn does not sound or sound Electric horn sounds loudly. hoarse. Turn signal lamp is dim. Turn signal lamp is bright. 1. Check if the connector to the battery is poorly Separate conductors of rectification regulator from contacted; cables of the whole vehicle. Measure and check with 2.
Symptom: Headlamp is dim. Diagnosis procedures Headlamp is dim AC power supplied lighting system DC power supplied lighting system Separate conductors of lead wire bundle of magnet from Turn on ignition switch; press horn button cables of the whole vehicle. Measure and check with an or slide turn signal lamp switch. ohmmeter if resistance between lead wire section output from magneto lighting coil is smaller than the standard. Yes No Electric horn sounds hoarse.
No Yes Check if power of bulb in the lighting system is up to the requirement. Yes 1. Check if contacts in headlamp switch and side-lamp switch are poorly contacted; 2. Check if connectors and earth wire are poorly contacted. No Replace bulb. Replace the bulb.
Symptom: Turn signal lamp is off. Diagnosis procedures Turn signal lamp is not on. Some of the turn signal lamps on one side is not on. All the turn signal lamps are not on. All the turn signal lamps on one side are not on. Take down the turn signal lamp Take down the turn signal lamp Press horn button and cover and check if the bulb is burnt. cover and check if the bulb is burnt.
Separate connectors of turn signal lamp switch and use Scintillator is damaged. a piece of wire to short circuit respectively power input line of the switch and power lines output to left and right turn signal lamps. Turn signal lamp is on after short Turn signal lamp is still off after short circuit. Inner contact of turn signal lamp is poor contacted.
Symptom: Electric horn mutes. Diagnosis procedures Electric horn mutes. Turn on ignition switch; slide turn signal lamp switch and check. Turn signal lamp is not lit or dim. Turn signal lamp shines brightly. Battery is low or the wire from battery Power supply from battery is normal. to ignition switch is broken or shorted. Pull out power line from power terminal of electric horn; touch the power line quickly with ground wire to check spark.
Symptom: Brake lamp does not work. Diagnosis procedures Brake lamp does not work. Take down cover of brake lamp and check if bulb is burnt. Yes No Replace bulb Use a piece of wire to short circuit two terminals of brake lamp switch or plugs of two hatching lines. Lamp is not lit after short circuit. Brake lamp is lit after short circuit.
Inspection/Adjustment Preparatory standard Compression pressure of cylinder Periodic maintenance schedule Engine oil Engine oil/filter Replacement of engine oil Steering stem bearing and handle fixation Drive chain slackness Throttle cable adjustment Front/rear brake clearance Air cleaner Headlamp Spark plug Clutch Battery Front/rear suspension system Carburetor Bolt/nut/fastening part Ignition timing Tyre specification Wheel rim/tyre Preparatory Standard General Warning！ • Before runni
Specifications Engine Idle speed rpm 1400±100rpm/min Spark plug clearance 0.6-0.
Periodic Maintenance Schedule Mileage and Every 300 KM Every 1000 KM Every 3000 KM Every 6000 KM Every 12000 KM Every 14500 KM New Vehicle One month three months Six months Twelve months Fifteen months C C R C interval Tools Items * Air cleaner I Common tool * Gasoline filter I I R Common tool * Engine oil filter C C C Common tool Common tool Tyre pressure gauge, air inflator Densimeter, multimter Engine oil replacement I I I I I I Battery inspection I I I I I
Expected Inspection 1 Ignition system -- perform maintenance inspection on obvious and continuous ignition malfunctions, engine fire, overheated back burning and others. 2 Carbon deposition removal -- obvious underpowered, get rid of carbon deposition on cylinder head, piston head and air exhaust system. 3 Piston and cylinder -- when cylinder is over worn or stuck, please replace it.
When the engine oil is completely drained, put back cleaned drain plug and sealing ring. Refill engine oil to specified level. Check if there is engine oil leakage. Start the engine and run the engine on idle for a few minutes. Check engine oil level again. Throttle Cable Adjustment *Attention Adjust properly engine idle before adjustment of throttle cable clearance. Check clearance of throttle cable, clearance shall be 3-5mm. If the clearance is not up to the specified, adjust it.
Replacing Time If driving under dusty condition or in rainy days frequently, replace the air cleaner earlier. * Attention While removing filter element of air cleaner, please do not run the engine, in case unfiltered air comes into the engine, which may result in fast wear of some components or damage the engine. On the other hand, rotation of engine without filter element may affect the carburetor and the carburetor will not work normally afterwards, which may result in overheated engine.
Battery Removal Remove the seat and take down the right protecting plate. Remove the battery from the battery case（1）. Disconnect the battery negative (-) lead wire first and then the positive (+) lead wire. Remove the battery. Warning! During positive lead wire disconnection, be sure to prevent the tools being used from touching the frame; or it will result in short circuit sparks, which may ignite gasoline and damage battery. It is dangerous! Install the battery in reverse order of removal.
may result in explosion. • During charging, please take the current time labeled on the battery as basic time. * Attention • Battery quick recharging is not recommended except in case of emergency. • After recharging, wait at least 30minutes and then measure the battery voltage. Recharging current: Recharging time: After recharging: Standard: 0.3A Quick recharging: 3.0A Standard: 10-15hours Quick recharging: 30minutes Open circuit voltage: over 12.
Compression Pressure of Cylinder Warm up engine. Insert the pressure gauge. Turn choke valve to its full open position. Set throttle handle to its full open position and kick start the engine. Compression pressure of cylinder: 1-1.2mpa * Attention Start the engine till reading of pressure gauge does not rise. Causes for low pressure: . Valve improperly adjusted . Valve leaks air. . Worn piston ring or cylinder Causes for high pressure: .
ruler into the engine. Do not tighten the ruler. Take out the engine oil ruler and inspect oil level. If oil level is lower or approaches the lower limit, add recommended oil to the upper limit mark. * Attention Check if sealing ring is damaged. Install the engine oil ruler. Engine Oil Replacement Warm up engine. Place an oil pan below the engine and drain engine oil by removing drain plug and oil ruler. Kick start engine several times to drain thoroughly the engine oil.
Screw off rear shaft nut and lock-nuts of adjusters on both drive chains. Rotate uniformly both adjusters till the drive chains gain normal slackness. * Attention Do not install new drive chains onto worn sprockets or install worn drive chains onto the new sprockets. Keep both sprocket and drive chain in good conditions, or newly replaced chain or sprocket will be worn soon. Clearance of front/rear brake Front brake clearance Measure the clearance of front brake at the tip of front brake handle.
Install a new headlamp bulb (7). Screw tightly the new bulb into the adapter. Avoid touching bulb glass with your bare hands during installation and staining it with oil, which may affect transparency, service life and luminous flux of bulb. If oil is adhered to the bulb, clean it with a cloth moistened with alcohol or highly volatile rubber solution. Install headlamp assembly. Clutch Check clearance of clutch cable. Clearance: 10-15mm. Adjust clearance of clutch cable. First loosen lock nut（1）.
Front/Rear Suspension System Front suspension Grasp the front brake handle and compress upward and downward the front shock absorber to check its actuator. Check if the front shock absorber leaks oil and if the components are loosened. Rear Suspension Compress upward and downward the rear shock absorber to check its actuator. Check if components on the rear shock absorber are loosened or injured. Lift and support the rear wheel and swing the wheel to check if engine suspension bushing is loosened.
Wheel Rim/Tyre Check if there is crack, nails and similar sharp objects, and other injuries on the tyres. Inspect pneumatic pressure of tyres. * Attention Measure the tyre pressure in cool state. Specified air pressure Unit: Kpa Tyre specifications Tyre pressure Front tyre 100/70-17 190±10kPa Rear tyre 130//60-17 210±10kPa QJ125-26A Tyre Specifications QJ125-26A Front tubeless tyre 100/70-17 Rear tubeless tyre 130//60-17 Check if lock nut of front shaft is loosened.
Inspection and Maintenance of Electric System Table of tightening torque for fastening parts used in electric system Fastening position and fastening part name Tightening torque（N·m） Starting motor clutch cover bolt 12 Starting motor clutch locknut 95 Rectifier bolt 5.0 High-voltage coil mounting bolt 9.0 Flywheel locknut 5.0 Vehicle block protecting plate bolt 9.
Charging System 1. Starting relay 2. Scintillator 6. Power lock assembly 3. Battery 4.
I Battery/Charging System Preparatory data------------1.1 Battery-------------------1.3 Fault diagnosis--------------1.2 Charging system-------------1.4 Voltage/current adjuster----------------------------------------------1.5 Magneto charging coil-------------------------------------------------1.6 Removal of magneto---------------------------------------------------1.7 1.1 Preparatory Data Precautions on operation * Attentions 1. The battery can be charged and discharged, and used repeatedly.
Preparatory Standard Item Specification Capacity/type Battery Magneto Voltage （20 ） 12V dry-charged type Fully recharged 13.1V Must be recharged 12.3V(not work for one hour) Recharging current Standard: 0.9A, Quick: 9A Recharging time Standard: 10-15hours; Quick: 30minutes Max. capacity 120W Coil impedance value（20 ） White-white 0.5-10Ω Type Full-wave rectification Battery recharging voltage 14.5V±0.4V/5.
1.3 Storage Battery 1.3.1 Battery Removal Take down the right protecting plate (1). Disconnect the battery negative (-) lead wire first and then the positive (+) lead wire. Remove the battery breather. Remove battery mounting bracket（2）. Remove the battery（3）. Warning! During positive lead wire disconnection, be sure to prevent the tools being used from touching the frame; or it will result in short circuit sparks, which may ignite gasoline and damage battery.
Recharging current: Standard: 0.3A Quick charging: 3.0A Recharging time: Standard: 10-15hours Quick recharging: 30minutes Recharging completed: open circuit voltage: over 12.8V 1.4 Charging System 1.4.1 Short circuit test Disconnect the grounding wire from the battery and use a voltmeter to connect battery negative lead wire with grounding wire. Set the switch at OFF position and check if it is shorted. * Attention Positive lead wire of multimeter is connected to negative lead wire of battery.
Check continuity between main wiring terminals in the following way: Item （wire color） Battery (red) and ground of vehicle block Ground wire (black) and ground of vehicle block Charging coil (white) and ground of vehicle block Between charging coils (while 1 and white 2) Judgment It is battery voltage. There is a lead wire. No power flowing between magneto coil and ground There is resistance between coils 1.5.
1.7 Magneto Removal * Attention Inspection of magneto lighting coil can be performed on the engine. 1.7.1 Inspection Disconnect the 4P connector on the magneto. Use a multimeter to measure impedance value between yellow coil of magneto and ground wire of vehicle block. Standard value：0.4-0.6Ω（20 ） If measured value exceeds the standard, the magneto coiling shall be replaced. 1.7.2 Removal Remove vehicle block protecting plate. Remove protecting plate of engine on the left side. Remove flywheel locknut.
* Attention There is magnetism on the inner surface of flywheel, ensure there is no bolt on it. Fix the flywheel using a universal non-adjustable spanner and then tighten the locknut. Torque value: 9.0 N·m Install protecting plate on the left side.
Ignition System Ignition System 1 Relay 2 Scintillator 3 Battery 4 Igniter 6.
II Ignition System Preparatory data-------------------2.1 CDI assembly--------------2.4 Fault diagnosis--------------------2.2 Ignition coil----------------2.5 Ignition system inspection-------2.3 Trigger----------------------2.6 2.1 Preparatory Data Precautions on operation 1. Ignition system inspection: please perform inspection in the sequence listed in the fault diagnosis table. 2.
2.2 Fault Diagnosis Spark plug no spark-over Symptom Possible causes（Determine the cause from 1 in sequence） Inner impedance is too small. Use appointed tester to test. Crankshaft rpm is too low. Ignition coil When the high voltage power is too low. Tester is disturbed (it is normal when more than one time’s measured voltage is above the basic）. Wiring of ignition system is poorly contacted. Ignition coil is no good. Charging coil is bad. (Peak voltage measurement) Tester is wrongly connected.
2.3 Ignition System Inspection * Attention • When there is no spark-over from the spark plug, check if components of wiring are loosened or badly contacted and make sure if all the voltage values are normal. • There are many brands of multimeters with different interior impedance. The values they measured are not the same. Connect a high-voltage shunt or an ammeter with input impedance higher than 10MΩ 10CV to the multimeter. 2.3.
Connecting method: positive (+) to blue/white, negative (-) to green/white. Min. voltage: higher than 1.7V. * Attention Please do not touch the metal parts of testing probe with your fingers while measuring the voltage, or you will be shocked. Please take care. When the peak voltage measured at connector of CDI assembly is abnormal, take down the protecting plate on the right side of vehicle and remove connector of magneto. Trigger (blue/white) is connected with a shunt.
2.5 Ignition Coil 2.5.1 Removal Remove protecting plate of vehicle block. Remove spark plug cap. Remove primary lead wire of ignition coil. Remove locknut of ignition coil and take out the ignition coil. Install it in the reverse order of removal. *Attention The primary coil is installed with black/white wire connector. 2.5.2 Primary coil inspection Measure impedance between terminals of primary coil Standard value: 0.4Ω±10％（20 ） Impedance value within the range is good.
2.6 Trigger * Attention Trigger inspection can be performed on the engine. Inspection Remove protecting plate of vehicle block. Remove lead-wire connector of trigger. Measure the impedance between blue/white terminal of lead wire at engine side and grounding vehicle block. Standard value: 100-200Ω（20 ） If measured impedance value is beyond the range, please replace the magneto.
Starting System Starting Diagram 1 Starting relay 2 Scintillator 6 Power lock assembly 7 Rectifier 3 Battery 4 Electronic igniter 8 Electric horn 5 high-voltage ignition coil
III Starting System Preparatory data-------3.1 Fault diagnosis--------3.2 Starting motor-----------3.3 Starting relay------------3.4 3.1 Preparatory Data Precautions on operation Starting motor removal can be performed on the engine. Starting clutch removal refers to removal instruction. Basic data Item Standard Service Limit Length of starting brush 12.5mm 8.5mm Starting idler shaft bushing 8.3mm Starting idler shaft OD 7.
3.2 Fault Diagnosis Starting motor will not run Starting motor runs weakly •Broken Fuse •Low battery •Low battery •Poor connecting wire contact •Defective ignition switch •Starting motor gear stuck by •Defective starting clutch foreign substances •Defective braking switch •Defective starting relay •Poor connecting wire contact •Defective starting motor Starting motor rotates but the engine does not •Defective starting clutch •Starting motor counter-rotate •Low battery 3.3 Starting Motor 3.3.
Inspect continuity between conducting terminal and brush. Replace it with a new one if abnormality exits. Inspect carbon brush holder for continuity. If there is continuity, replace it. Measure brush length Service limit: replace it when it is shorter than 8.5mm Check rotation smoothness of the needle bearing in the front cover and whether it is loosened when it is pressed in. If there is abnormality, replace it with a new one. Check the oil seal for wear and injury. 3.3.
3.4 Starting Relay 3.4.1 Actuation Inspection Take down the protecting plate of vehicle block. When the ignition switch is set at “ON” position, press starting motor and a “Click” sound can be heard. Inspect Sound. “Click” sound indicates normal. No sound: • Check starting relay voltage. • Check starting relay ground wire loop. • Inspect starting relay actuation. 3.4.2 Starting relay voltage inspection Lift and support the main stand.
Bulbs/Switches/Instruments 1 Headlamp 2 Instruments 3 Electric horn 4 Left rear turn signal lamp
IV Bulbs/Switches/Instruments Preparatory data---------------------------------------------------4.1 Fault diagnosis----------------------------------------------------4.2 Headlamp bulb replacement------------------------------------4.3 Front turn signal lamp bulb replacement---------------------4.4 Tail lamp bulb replacement ------------------------------------4.5 Instrument--------------------------------------------------------4.6 Ignition switch---------------------------------------------------4.
4.3 Headlamp Bulb Replacement 4.3.1 Removal Screw off with a wrench locknut（1） of headlamp and take down the headlamp. Pull out socket of headlamp adapter and remove the rear cover. Release circlip and take out of the lamp adapter. * Attention When the bulb is lit, keep you hands and inflammable materials some distance away from it. Lighting bulb is hot; touch it when it cools down. 4.3.2 Installation Install the new bulb, adapter and headlamp rear cover. Tighten the new bulb into the socket.
4.5 Tail Lamp Bulb Replacement 4.5.1 Removal Screw off the two bolts（1）. Remove the tail lamp hood. Disconnect wire connector to the tail lamp. While pressing down the tail lamp, rotate it counterclockwise Remove the tail lamp 4.5.2 Installation Install the tail lamp in the reverse order of removal. * Attention While installing tail lamp, be sure that sealing washer on the tail lamp hood is in good condition and correct position. 4.5.3 Tail lamp bulb replacement 4.5.3.
4.7 Ignition Switch and Steering Lock 4.7.1 Inspection Remove the headlamp from the cover. Remove ignition switch-wire connector. “ ” (OFF) position：All the circuits are broken. “ ” (ON）position：Ignition circuit is switched on and engine can be started. When the switch is at this position, the key cannot be pulled out.
Remove the draw-bar bracket for the rear brake lever. Remove throttle handle and bolts. Take down throttle handle from the handle and remove the throttle cable. Remove locknut on the handle and take down the handle.
Chassis Inspection and Maintenance Table of Tightening Torque of Fastening Part on Chassis Fastening position and part name Tightening Torque（N·m） Oil pump block assembly mounting bolt 5-9 Front brake cylinder assembly mounting bolt 22-29 Rear brake rocker arm mounting bolt 5-9 Rear shaft locknut 85-98 Upper bracket assembly mounting bolt 40-60 Front shaft locknut 55-62 Front shock absorber mounting bolt 37-44 Rear shaft locknut 85-98 Rear shock absorber top nut 37-44 Rear shock absorber
Front Hydraulic Brake A B C D Front brake disc diameter：240mm Front brake disc thickness：4.0mm Service limit：3.
Rear Drum Brake A Rear brake ID：130mm B Service limit：131 C D Brake shoe thickness：4mm Service limit：3mm Mounting torque for Bolt 21 in the diagram：22-29 N·m 1 Nut M14 2 Rear hub cap assembly 3 Copper pin 2×18 4 Nut M8 5 Rear hub cap mounting bolt 6 Bolt M6×30 7 Washer 6 8 Rear brake rocker arm 9 Nut M6 10 Washer 11 Cam shaft O sealing ring 12 Rear braking cam shaft 13 Rear wheel right bush 14 Rolling bearing 6302-2RS 15 Braking shoe tension spring 16 Braking shoe assembly 17 Tube and tyre 110/80-17
V Braking System Maintenance instruction--------------------5.1 Fault diagnosis-------------------------------5.2 Front hydraulic disc brake----------------- 5.3 Rear drum brake-----------------------------5.4 5.1 Maintenance Instruction Precautions on operation * Attention • Please do not contaminate braking assembly with oil while assembly or disassembly. • Please use specified detergent to clean the braking assembly, or it may reduce braking performance.
3. Braking shoe assembly improperly installed 3. Braking shoe assembly improperly installed 4. Braking shoe assembly and brake disc contaminated Noisy Braking 1. Braking shoe assembly and brake disc are worn. 2. Braking shoe assembly and brake disc are contaminated 5.3 Front Hydraulic Brake 5.3.1 Removal * Attention • Replace braking shoe assembly.
Specifications QJ125 Front brake disc diameter φ260mm Front brake disc thickness 4.0mm * Attention • Micrometer shall be used for the measurement. Measure the thickness of braking shoe. If brake disc and braking shoe are contaminated by grease or their thickness is smaller than service limit, replace them. Service limit: Braking shoe: 3mm Brake disc: 3mm Note: Braking shoes shall be replaced in pairs. 5.3.3 Installation Install brake disc and front wheel.
5.4 Rear Drum Brake •5.4.1 Removal * Attention • Replace braking shoe. • If a braking shoe assembly will be used again, please mark it on the side before removal so that is can be re-installed easily to its original place. Remove the following rear brake assembly from the rear wheel: 1. Bolt M6Χ35（6） 2. Rear brake rocker arm（8） 3. Nut M6（9） 4. Rear wheel shaft locknut (1) 5. Rear brake return spring 6. Rear brake cam shaft（12） 7. Braking shoe assembly（16） 8. Braking shoe spring（15） 9. Tyre 3.00-18（17） 10.
Install brake pedal assembly（21） * Attention A contaminated braking shoe will reduce braking performance and result in braking failure. Tighten bolt and nut to their specified torque value. Torque value: Rear wheel locknut: 85-98 N·m Do not contaminate braking shoe with oil. If a braking shoe is polluted by oil, clean it with brake cleaner. * Attention A contaminated braking shoe will reduce braking performance Note: Detailed breakdown drawing refers to P86.
Exterior Parts Attention Do not damage exterior parts during disassembly and assembly. Do not damage the pawls on the exterior parts of the vehicle during assembly or disassembly. Align built-in panel and cover plate to their grooves respectively. Correctly install pawl of each part during combination. Do not damage the fittings during exterior part installation.
VI Motorcycle Exterior Disassemble the motorcycle body in the following sequence: Seat cushion assembly → Left and right protecting plate assemblies → Left and right tail covers → Left and right hanger → Left and right hanger → ↓ Left and right pedals → Front mudguard brace panel → Front mudguard → Rear mudguard assembly → Rear rail → Rear tail cover connectiong board → Tail lamp → Tail lamp support * Attention Do not damage exterior parts during assembly and disassembly.
Front wheel / Front Suspension 1 Front wheel shaft 2 Gear seat assembly 3 Gear seat oil seal 4 Drive plate 5 Bearing 6 Front wheel middle sleeve 7 Front brake disc 8 Front brake disc mounting bolt 9 Front wheel oil seal assembly 10 Front wheel left sleeve 11 Tubeless tyre 12 Front wheel rim
Control Assembly A Tightening torque of hexagon Socket screw 2：37-44 N·m B Tightening torque of Nut 19：5-9 N·m C Tightening torque of Screw 20：5-9N·m 1 Right rear mirror assembly 2 Left rear mirror assembly 3 Bolt 4 Handle gear block 5 Right handle assembly 5 Right combination switch 6 Right combination switch 7 Steering handle welded assembly 8 Left combination switch 9 Left steering handle jacket 10 Left handle assembly 11 Left handle 12 Slotted Nut 13 Handle mounting bolt 14 Bolt M6×25 15 Fixed co
Front Fork Assembly Tightening A torque for Bolt 16 （Steering stem mounting bolt） in the diagram：40-60 N·m B C D Tightening torque for Bolt 19 in the diagram：22-29 N·m Tightening torque for Bolt 29 in the diagram：37-44N·m Number of upper steel balls：23 Number of lower steel balls：19 1 Right front shock absorber assembly 2 Inner pipe 3 Oil seal 4 Left front shock absorber assembly 5 Lower steel bowl of upper bearing 6 Upper steel bowl of lower bearing 7 Cable clip 8 Lower steel bowl of lower beari
VII Front Wheel/Front Suspension Preparatory data-----------------7.1 Fault diagnosis------------------7.2 Front wheel----------------------7.3 Control assembly---------------7.4 Front fork assembly------------7.5 7.1 Preparatory Data Precautions on operation Before removing the front wheel, lift and support the bottom of motorcycle with a jack or other available device. The front wheel is off the ground. Take care not to rotate the wheel reversely.
7.2.2 Wobbly Direction Handle Damaged handle bearing. Not enough tyre pressure. Front fork bent, front wheel shaft bent. Distorted and crooked front wheel tyre. 7.2.3 Wobbly Front Wheel Distorted wheel Worn front wheel bearing Defective front tyre 7.2.4 Difficult Rotation of Wheel Shaft or bearing seat fault Braked 7.2.5 Noisy Front Shock Absorber Friction sound of shock absorber protecting plate Loosened bolts on the shock absorber. 7.3 Front Wheel 7.3.
Place the shaft onto a V block and measure its eccentricity with a dial gauge. Service limit: When the measured value exceeds 0.2mm, replace it. 7.3.2.2 Wheel Shimmy Inspection Place the wheel onto a precise support and check its amplitude of shimmy. Rotate the wheel with your hands and read out shimmy amplitude. Service limit: Longitudinal: replace it when it is over 2.0mm Transversal: replace it when it is over 2.0mm. 7.3.2.3 Front Bearing Inspection Remove front shaft (1) and brake disc (12).
Lubricate front shaft, gear seat assembly, oil seal (lip), sleeve, bearing 6301-2RS, and middle sleeve. Recommended lubricant is calcium base grease. Install front shaft（3）, front wheel, gear seat assembly（2）and Nut M12Χ1.25. Gear seat assembly shall be halved at installation. If odometer gear seat assembly does not align and lock the front shaft, the odometer gear seat will be distorted. Install front brake assembly to the front brake disc. Tighten front shaft.
7.5 Front Fork 7.5.1 Removal Support the motorcycle with the middle stand. Remove front wheel. Remove brake caliper and brake pipe clip. Remove front mudguard（1） and reflector（2）. Remove the handle. Screw off upper bracket mounting bolt and lower bracket pinch bolt. Remove headlamp bracket. Remove the front fork.
7.5.3 Installation Apply lubricating grease onto the bottom bearing steel bowl and confirm the number of steel balls (23balls). Steering handle shall not be rotated in case of steel ball falling off; then install steering rod. Support the steering handle and apply lubricating grease on to the top bearing steel bowl and confirm the number of steel balls (19 balls) Apply lubricating grease on the top holder race. Turn steering handle left and right to have steel balls closely fit.
Rear Wheel/Rear Suspension 1 Rear shock absorber assembly 2 Rear brake rocker arm 3 Sprocket 43 teeth 7 Oil seal 8 Rolling bearing 6204-2RS Sprocket mounting bolt 12 Rear wheel left sleeve assembly Tubeless tyre 16 Rear wheel left sleeve 17 Rear braking shoe M14×1.
Rear Shock Absorber 1 Cap nut M10×1.25 2 Rear shock absorber mounting gasket 4 Washer 12 Bolt M10×1.
Rear Swing Arm A Side clearance（opening swing arm end） limit value：1.0mm B Tightening torque of Nut 1 in the diagram is：70-83 N·m 1 Locking nut M14X1.
Chain Drive Assembly Tightening torque of A Bolt 1 in the diagram is：22-29 N·m Drive chain B specification： 428H-1×126 1 Sprocket mounting bolt 2 Sprocket hub 6 Sprocket 43 teeth 7 Sprocket stopper 3 Chain drive sleeve 4 Rolling bearing 6204-2RS 5 Oil seal 8 Nut M8 9 Chain 428H-1×126 10 Chain guard 11 Boss bolt
VIII Rear Wheel/Rear Suspension Preparatory data----------------------------------- 8.1 Fault diagnosis-------------------------------------8.2 Rear wheel----------------------------------------- 8.3 Rear shock absorber/rear swing arm----------- 8.4 Chain drive assembly-----------------------------8.5 8.1 Preparatory Data Precautions on operation Do not contaminate braking shoe ad brake disc with oil. Basic preparatory data Item Rear wheel Shimmy Standard Value（mm） Service Limit（mm） Longitudinal 2.
8.2.2 Inflexible Wheel Rotation Incorrect brake adjustment Worn rear bearing Too tight the drive chain 8.2.3 Poor Braking Performance Incorrect brake adjustment Worn braking shoe Worn brake drum Incorrect installation of braking shoe 8.2.4 Brake Pedal Inflexible or Slow Return Worn or broken return spring Incorrect brake adjustment Worn or contaminated brake drum Incorrect installation of braking shoe 8.2.
8.3.2 Inspection 8.3.2.1 Wheel Shimmy Inspection Rotate the wheel by hands and measure its eccentricity with a dial gauge. Service limit: Longitudinal: Replace it when the measured value exceeds 2.0mm. Transversal: Replace it when the measured value exceeds 2.0mm. When rear wheel shimmy exceeds service limit, rear wheel bearing is loosened, which results in wobbly rear wheel. Check and replace rear wheel bearing. 8.3.3 Installation Install the rear wheel in the reverse order of removal and tighten the nut.
8.4 Rear Shock Absorber/Rear Swing Arm 8.4.1 Remove Rear Shock Absorber Remove left and right protecting plates, seat cushion assembly and hood. Screw off top and bottom mounting bolts and cap nut （1） from rear shock absorber. Remove the rear shock absorber. 8.4.2 Rear Shock Absorber Inspection Check rear shock absorber rod. If the rod is bent or damaged, please replace rear shock absorber assembly. Check fatigue of spring. If it is, replace rear shock absorber assembly. 8.4.
8.4.5 Rear Swing Arm Inspection Check rear swing arm installation shaft. Rotate the shaft on a flat surface or measure it with a dial gauge. If it is bent, replace it. * Attention Don’t attempt to straighten bent shaft. Wash in solvent the components for rear swing arm installation shaft. Check sleeve assembly of rear swing arm（7） and intermediate sleeve (5). If they are damaged, replace them. 8.4.6 Install Rear Swingarm Install the rear swing arm in the reverse order of removal.
Length limit of 10 chain links is 127 mm. * Attention: • Stretch the chain by hands and then measure it. • The measuring range is from chain link roller side of roller ○,11. to inner • Measure length of 10 chain links. • Measure length of 10 chain links for 2-3 times at different positions. Clean drive chain. Immerse it into kerosene and brush the dust on it as possible as one can. Take the cleaned chain from kerosene and dry it in the air. Inspect roller and its side plate .
Check wheel bearing. If there is bearing clearance in the wheel hub or rotation of the wheel is unbalanced, replace it with a new one. Check oil seal. If it is worn or broken, replace it with a new one. 8.5.4. Installation Install it in the reverse order of removal. Install drive chain, chain cover, rear left shock absorber, rear wheel and drive sprocket cover. Adjust slackness of drive chain and clearance of brake pedal.
Seat Cushion 1 Seat cushion assembly 2 Rear rail 3 Rear luggage carrier screw II 4 Rear luggage carrier screw I
Fuel Tank Assembly A Max. capacity of fuel tank：16L B Tightening torque of Bolt 13 in the diagram：5-9 N·m D Tightening torque of Bolt 15 in the diagram：5-9 N·m E Note：Fuel switch shall be set at “OFF” position while removing fuel tank.
IX Fuel Tank/Seat Cushion Preparatory data----------------------9.1 Fault diagnosis-------------------9.2 Fuel tank/seat cushion-----------9.3 9.1 Preparatory Data Precautions on Operation Working site for removal shall be away from fire source. Fuel switch shall be set at “OFF” position while removing fuel tank. While installation, tighten bolt and nut to their specified torque. After installation, check if all the components are correctly fixed and work normally.
9.3 Fuel Tank/Seat Cushion 9.3.1 Removal Remove left and right protecting plates. Insert ignition key into the seat lock. Rotate clockwise the key and unlock it. Pull downward and take out the helmet hook. Release the pawl from frame and remove seat cushion (1） Remove connector from lead wire of oil level sensor. Fuel switch shall be set at “OFF” position. Disconnect fuel hose and carbon canister connecting hose. Remove bolt, washer, damper and fuel tank. Remove the fuel tank from the frame.
Engine Inspection and Maintenance Table of tightening torque for fastening parts used in Engine Fastening position and part name Tightening torque（N·m） Cylinder cap nut M8 25～28 Cylinder cap nut M6 8～12 Cylinder cap bolt 8～12 Cylinder block connecting bend bolt 8～12 Cylinder block connecting nut 8～12 Flywheel locknut 50～55 Valve clearance adjuster 10～15 Gearshift changeover contact screw 8～12 Closing bolt 8～12 Right side cover bolt 8～12 Front left cover bolt 8～12 Coil screw 8～12 Cl
Lubricating System Note: When the engine oil pump is removed, clean carefully all the components and purge them with high-pressure gas. During engine oil pump removal and installation, pay attention not to drop anything into the crankcase.
X Lubricating System Preparatory data--------10.1 Fault diagnosis---------10.2 Oil engine pump-------10.3 10.1 Preparatory Data Precautions on Operation When the engine oil pump is removed, clean carefully all the components and purge them with high-pressure gas. During engine oil pump removal and installation, pay attention not to drop anything into the crankcase.
10.3 Oil Pump Oil pump gear 10.3.1 Removal Remove right cover. Take down the engine oil filter and release oil pump mounting screw. Take down oil pump block, drive gear and pump shaft. Oil pump block Screw off the screw Take down pump seat. Screw Screw Engine oil pump Engine oil pump Remove the screw and take down pump cover. Disassemble oil pump Testing gauge Check radial clearance between inner rotors Allowable limit: 0.2mm.
Check clearance between external rotor and oil pump seat. Allowable limit: 0.2mm. Testing gauge Check clearance between rotor end faces. Allowable limit: 0.15mm.
10.3.2 Assemble Engine Oil Pump As shown in the following figure: * Attention: After assembly, inner and external rotors shall rotate smoothly and be out of nimbleness. 10.3.2 Installation Install the oil pump in the reverse order of removal.
Carburetor Attention: Gasoline is very dangerous. Fire and smoking are forbidden in working site. When the carburetor is removed, plug the intake pipe side with a cloth in case foreign matters coming in.
XI Carburetor Preparatory data--------------11.1 Fault diagnosis--------------- 11.2 Carburetor removal---------- 11.3 Carburetor installation-------11.4 11.1 Preparatory Data Precautions on Operation ·Gasoline is very dangerous. Fire and smoking are forbidden in working site. ·Pay specially attention to sparks. ·Please do not pull and bend wires and cables by force. Distortion and injury may affect operation of cables.
Clogged oil filter Clogged oil pipe Sticky needle value Improper oil level adjustment Too high or too low mixed gas concentration Secondary air sucked by the intake system Improper idle adjustment Improper oil level adjustment Clogged idle system or electric enrich valve Too much fuel in engine Too low mixed gas concentration Oil outflow Secondary air sucked by fuel system Degraded fuel Improper work of enrich valve Clogged idle system or choke system Clogged oil nozzle Clogged needle valve Too low oil
11.3.3 Inspection Check if needle valve assembly, needle valve seat and float assembly are worn or broken. If needle valve core is worn or broken, replace it with a new one. If needle valve seat is worn, the main carburetor body shall be replaced. If the tongue plate of float is worn, replace it. Check if oil needle of carburetor is worn or broken. If it is, replace it and main nozzle together. Check if idle jet, main jet or main nozzle is worn, broken or contaminated. If it is, replace it.
Cylinder Head/Valve 1 Limit screw 2 Washer 3 Cylinder cover hood bolt 4 Valve cover 5 O ring 6 Cylinder cover hood bolt 7 Plug 8 O ring 9 Rocker arm shaft 10 Wave spring washer 11 Rocker arm 12 Rocker arm return spring 13 Cylinder cover hood 14 Spark plug assembly 15 Cover nut 16 Washer 17 C-type gasket 18 Cylinder cover nut 19 Copper washer 20 Round pin 21 Locknut 22 Adjusting screw 23 Valve collet 24 Valve spring upper retainer 25 Valve spring 26 Valve rod sealing assembly 27 Valve guide 28 Valve spring
XII Cylinder Head/Valve Preparatory data-----------------12.1 Valve guide replacement-------------12.5 Fault diagnosis------------------12.2 Valve race fixing and adjustment---12.6 Cylinder head--------------------12.3 Cylinder head installation------------12.7 Valve Inspection---------------- 12.4 12.1 Preparatory Data Precautions on Operation To ensure sealing between cylinder head and cylinder body, there is a great bolt pretension on the cylinder head. Pretension value: 50Nm.
12.2 Fault Diagnosis Low compression pressure Noisy cylinder head Improperly adjusted valve clearance Valve burnt or bent Improperly adjusted valve clearance Valve spring hurt Poorly sealed valve race Too high compression pressure Air leakage at cylinder head Improperly installed spark plug Too much carbon deposited in the combustion chamber 12.3 Cylinder Head 12.3.1 Removal Bolt Screw off the ten locknuts and remove cylinder cover.
Measure rocker arm shaft OD. Allowable limit: 11.95mm. Measure rocker arm hole ID Allowable limit: 12.05mm. Clearance between rocker arm and rocker arm shaft Micrometer Allowable limit: 0.08mm Tester Screw off the two locknuts and remove the lock washer, cam shaft and C-type gasket.
Valve collet Compress valve spring with a valve spring compressor, and remove the valve collet. Remove in sequence spring disc, external and inner valve springs, external valve spring washer and valve. 12.3.2 Disassemble Valve Washer Inner valve spring Valve collet Valve Spring disc External valve spring Valve oil seal Ruler 12.4 Valve Inspection Clean carbon deposition on the cylinder cover. Measure flatness of junction surface of cylinder cover Allowable limit: 0.05mm.
Allowable limit: Internal spring: 30mm. External spring: 37.8mm. Measure OD of valve stem Allowable limit: 4.9mm. Check valve guide. Please eliminate the carbon deposition in the valve guide with a reamer before inspection Attention: Rotate the reamer in clockwise. Please do not rotate he reamer in counterclockwise. Measure valve guide ID. Allowable limit: Intake/Exhaust: 5.5mm. Clearance between valve and valve guide Allowable limit: Intake Valve: 0.08m. Exhaust valve: 1.
Opener 12.5 Valve Guide Replacement * Attention: When the clearance between valve and valve guide exceeds service limit value, please replace the valve guide. When a valve guide is replaced, surface of valve seat retainer shall be fixed and adjusted. Put the valve guide into the freezing chamber of refrigerator for one hour to freeze it. Heat with electric furnace or oven the cylinder head to 100-150 .
12.6 Valve Race Fixing and Adjustment Hackly part Remove hackly and ragged parts on the valve race with a 45°angled milling cutter. Note： Apply a layer of transparent or Prussian blue film onto the valve race so that it can be observed clearly. Remove 1/4 of external edge of valve race with a 32° angle milling cutter. 32° Remove 1/4 of bottom of valve race with a 60° angle milling cutter. Remove the milling cutter and check the places processed.
If contacted place is the higher part of valve, please use a 32°angle plain milling cutter to lower the valve race. If contacted place is the lower part of valve, please use a 60°angle internal milling cutter to raise the valve race. Grind and cut valve race with a 45°angle precise milling cutter till it meets the required specification. After completion of valve race grinding and cutting, please apply some polishing agent on the surface of valve. Polish the valve gently.
Cylinder Block and Piston Attention: All the components shall be cleaned before inspection and test, and purged with high-pressure air.
XIII Cylinder Block and Piston Preparatory data------------13.1 Fault diagnosis--------------13.2 Cylinder block--------------13.3 Piston---------------------- 13.4 Cylinder installation-----13.5 13.1 Preparatory Data Precautions on Operation All the components shall be cleaned before inspection and test, and purged with high-pressure air. Function of cylinder block: Cylinder block provides the space for gas compression, combustion and expansion and guides piston movement.
13.2 Fault Diagnosis Low compression pressure White smoke from exhaust pipe Worn, burnt or broken piston Work or damaged cylinder and piston Broken washer, air leakage on crankcase Worn or damaged piston ring Worn or damaged cylinder and piston Higher compression pressure Noisy piston Too much carbon deposited in the combustion chamber Damaged cylinder, piston and piston ring Worn piston pin hole and piston pin 13.3 Cylinder Block Cylinder block 13.3.
13.4 Piston 13.4.1 Removal Remove piston pin retainer. * Attention: Please do not drop the retainer into crankcase during removal. Take out piston pin and remove piston. Piston pin ring, piston pin Remove piston ring. Inspect piston, piston pin and piston ring. * Attention: Please do not break or hurt piston ring. Remove deposited carbon inside the piston ring. Piston Testing gauge Install the piston ring. Push Measure the clearance between piston ring and piston ring groove.
Measure piston pin hole ID. Allowable limit: 14.04mm. 3 Measure piston pin OD. Allowable limit: 13.96mm. Measure the clearance between piston pin hole and piston pin. Allowable limit: 0.05mm. Measure piston OD * Attention: Measuring position forms a 90°angle with piston pin, about 11mm below piston skirt. Allowable limit: 56.93mm. Inspect wear and scratch on inner wall of cylinder. * Attention: Measure cylinder ID at three positions, i.e. upper, intermediate and lower positions.
Measure the roundness of cylinder inner wall. （internal diameter difference between X direction and Y direction）. Allowable limit: 0.05mm. Measure the cylindricity of inner wall of cylinder. （internal diameter difference of three positions (upper, intermediate and lower) along X direction or Y direction）. Allowable limit: 0.05mm. Check flatness of cylinder surface. Allowable limi: 0.05mm. Ruler Testing gauge Cylinder Connecting rod small end ID Measure Connecting rod small end ID. Allowable limit: 14.
Scrape the washer attached to the crankcase. * Attention: No foreign matters can be dropped into the crankcase. Install piston, piston pin and piston pin retainer. * Attention: Install with the “Point” mark at the bottom of piston facing the exhaust valve. “point” Mark 13.5 Install Cylinder Install washer and location pin onto the crankcase. Location pin Washer Apply evenly engine oil on inner wall of cylinder, piston and piston ring. Install carefully the piston ring into the cylinder.
Clutch Attention: You don’t have to remove the engine from frame while overhauling clutch. Viscosity and level of engine oil will affect operation of clutch. Please check first engine oil and oil level before inspect clutch. If one of the cluth springs, discs or plates does not work, you shall replace them in pairs.
XIV Clutch Preparatory data-----------------------------------------------14.1 Fault diagnosis------------------------------------------------14.2 Clutch---------------------------------------------------------- 14.3 Kick start mechanism----------------------------------------14.4 Disassembly of main shaft and countershaft--------------14.5 14.1 Preparatory Data Precautions on Operation You don’t have to remove the engine from frame while overhauling clutch.
Bent gearshift spindle Injured gearshift cam Bent or injured gearshift plate Warped clutch plate Faulty clutch push rod Abnormal engine oil and oil level 14.3 Clutch 14.3.1 Removal Screw off the four bolts for separating plate in criss-cross mode. Remove release lever, sleeve, bearing, separating plate and clutch spring. Removed components refer to exploded view. Use a special tool to screw off clutch locknut. Remove locknut and washer. Remove clutch center bracket.
14.3.2 Disassemble Clutch 14.3.3 Inspection Check if there are burs or broken parts on the housing groove of clutch. If there are, fix and adjust with a file. If there is a lot for fix and adjustment, replace it. Check if teeth of pressure plate and center bracket are injured. If they are, replace them. Measure the free length of pressure spring. Allowable limit: replace it if it is below 29.7mm.
Measure the thickness of friction plate with a vernier caliper. Allowable limit: Replace it when it is below 2.6mm. Thickness 14.4 Disassemble Main Shaft and Countershaft Tooth 齿面 Surface Inspection Check respectively wear of tooth surface and drive pawls. If they are seriously worn or damaged, replace them. Remove bearing and oil seal on left crankcase. Check if bearing and oil seal are injured. Replace if necessary.
* Attention: Hammered-out bearing cannot be reused. Replace it with a new one. Remove bearing and oil seal with special tools. Bearing hole, oil seal hole Remove bearing on right crankcase. Check if bearing is injured. Replace if necessary. * Attention: Hammered-out bearing cannot be reused. Replace it with a new one. Remove bearing and oil seal with special tools. Main shaft and countershaft combination * Attention: Apply each gear and shaft with lubricating grease evenly at combination.
Reduction Gear Function: Transfer torque and determinate the final output torque and rotary speed.
XV Reduction Gear Preparatory data-----------------15.1 Fault diagnosis------------------15.2 Gearshift mechanism----------15.3 Installation----------------------15.4 15.1 Preparatory Data Function: Transfer torque and determinate the final output torque and rotary speed. Basic data Gearshift mechanism Unit: mm Shift fork shaft OD Diameter of shift fork inner hole Shift fork thickness Gearshift hub OD Gearshift hub lock groove width 9.98-9.995 10-10.015 4.8-4.9 39.8-40 6.1-6.2 9.96 10.05 4.6 39.75 6.
15.3 Gearshift Mechanism 15.3.1 Removal Remove gearshift shaft assembly. Remove the bolt on the upper baffle plate of ratchet, the ratchet upper baffle plate and gearshift ratchet gear ring. Remove the bolt on lower baffle plate of ratchet, the ratchet lower baffle and the ratchet, etc. Removed parts refer to exploded view. . 15.3.2 Exploded View 15.3.3 Inspection Before disassembly, gearshift plate shall work flexibly and smoothly. Check if gearshift plate and gearshift shaft assembly are worn.
Remove left case block. Pull out shift fork shaft. Remove gearshift drum. Remove gearshift fork. Shift fork shaft Gearshift drum Shifting fork Measure shift fork OD. Allowable limit: 9.96mm. Micrometer Measure shift fork hole ID. Allowable limit: 10.05mm. Tester Vernier caliper Measure shift fork thickness. Allowable limit: 4.6mm.
Measure OD of gearshift drum Allowable limit: 39.75mm. Measure the width of gearshift drum lock groove Allowable limit: 6.35mm. Lock groove width Remove balance shaft gear Balance shaft gear 15.4 Installation Install it in the reverse order of removal.
Crankcase Attention: Crankcase is a thin-wall casting part. Avoid impact on it during operation in case it may be distorted or broken. Clean carefully all the components before inspection and test and purge them with high-pressure gas. Drain the lubricating oil from crankcase before working on it.
XVI Crankcase Preparatory data-----------------16.1 Fault diagnosis--------------16.2 Crankcase--------------------16.3 16.1 Preparatory Data Precautions on Operation Attention: Crankcase is a thin-wall casting part. Avoid impact on it during operation in case it may be distorted or broken. Clean carefully all the components before inspection and test and purge them with high-pressure gas. Drain the lubricating oil from crankcase before working on it.
16.3 Crankcase 16.3.1 Crankcase Removal Screw off starting motor mounting bolts，and remove starting motor. Release starting motor gear chamber cover mounting bolt and remove gear chamber cover. Remove starting motor gear, needle bearing and washer. Screw off bolts on left front cover and left rear cover of crankcase. Remove left front cover and left rear cover. Remove starting motor idle gear. Remove washer and location pin. Use an electric or pneumatic tool to screw off flywheel locknut.
Remove gear display. Remove cam shaft limit plate and take down cam assembly. Remove bearing locating device. 16.3.2 Exploded View of Cam Assembly Camshaft gear Cam mechanism shaft Cam shaft spring Cam Measure cam bush ID. Allowable limit: 14.10mm. Measure cam height Allowable limit: 32.5mm.
16.3.3 Crankcase Right Cover Removal Tester Bolt Screw off mounting bolt and take down the crankcase right cover. Remove clutch release lever assembly from the right cover. Right cover Right cover Release lever assembly Remove screws, engine oil filter roller cover and its cover washer. Remove washer and location pin. Washer Cover of oil filter roller Location pin Use an electric or pneumatic tool to screw off locknut. Remove oil filter roller and take down the drive gear.
16.4 Crankshaft Connecting Rod Assembly Crankshaft connecting Removal rod assembly Drive gear Location pin Remove left crankcase. Remove washer and location pin. Remove drive gear. Washer Remove the crankshaft connecting rod assembly from the right crankcase. * Attention: Please do not hurt washer and closing surface. Inspection Measure connecting rod big end left-to-right clearance. Allowable limit: 0.55mm. Measure connecting rod big end clearance along X-Y direction. Allowable limit: 0.05mm.
Exhaust System Inspection and Maintenance Muffler Assembly A Tightening torque of mounting bolt 5 for muffler connector in the diagram：5-9 N·m B Dual catalysts are added into the muffler welding assembly in the diagram.
XVII Emission Control System Emission control system guarantee----------------------------------------- 17.1 Periodical maintenance instructions/ensure emission standard--------- 17.2 Emission control system mechanical function-----------------------------17.3 Solutions to Idle exhaust exceeding specified value ---------------------17.4 17.1 Emission Control System Guarantee 1. The emission control system of the motorcycle is up to the Standard of China Stage III.
17.2 Periodical Maintenance Instructions ·To reduce environment pollution, it is required by the country that all the motor vehicles manufactured by each company shall meet the regulations of emission standard of air pollutants. Besides the production process is up to the regulations of emission standard of air pollutants, the company is also devoted to purifying air and reducing air pollution.
Classification Equipment Constituted Part Emission control system Catalytic device Catalytic converter Desired Function Oxidize CO, HC and NOX. 17.4 Solutions to Idle Exhaust Exceeding Specified Value (4-stroke) Qualified Perform regular inspection（Repair and maintenance plan） Qualified Measure Idle exhaust (Note 1） Qualified Adjust carburetor（Note 2） Qualified Disassemble and clearn carburetor （SJ, MJ, SAJ, MAJ, etc.） For Delivery.
QJ125-26A Schematic Circuit Diagram
