KEEWAY QJ50T-21U Maintenance Manual Download Page 1

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Motorcycle QJ50T-21U

Maintenance Manual

Qianjiang Motor Corporation Ltd.

Summary of Contents for QJ50T-21U

Page 1: ...1 Motorcycle QJ50T 21U Maintenance Manual Qianjiang Motor Corporation Ltd...

Page 2: ...nition System Check 64 2 4 CDI Group 65 2 5 Ignition Coil 66 2 6 Trigger 67 III Startup System 69 3 1 Preparing documents 69 3 2 Failure diagnosis 70 3 3 Startup Motor 70 3 4 Starter Relay 72 IV Bulbs...

Page 3: ...otor 110 10 4 Installation 111 Inspection and Maintenance of Engine 112 11 Lubricaiting System 114 11 1 Preparation Documents 114 11 2 Failure Diagnosis 114 11 3 Fuel Pump 115 12 Carburetor 118 12 1 P...

Page 4: ...143 16 4 Installation 144 17 Crankcase 146 17 1 Preparing Documents 146 17 2 Failure Diagnosis 146 17 3 Crankcase 147 17 4 Installation 149 Inspection and Maintenance of Exhaust Emission System 150 1...

Page 5: ...ns shall be carried out from the beginning of periodic inspection Except for Chapter I the rest chapters explain the disassembly assembly inspection of engine entire motorcycle and electrical parts Br...

Page 6: ...plosive gas Therefore it shall be far away from fire sources naked flame or smoking places Make sure good ventilation during charging Battery contains sulfuric acid electrolyte It will burn your skin...

Page 7: ...ressor after disassembly and before measurement of attrition value Solvent or oil can easily damage aging rubber articles Check rubber before reassembly and replace rubber if necessary boot When loose...

Page 8: ...alling a hose fuel vacuum or cooling agent insert its end into the bottom of the connector so that the hose clip can properly fix the connector Rubber or plastic dirt proof boot shall be mounted at th...

Page 9: ...be clamped during moving Cables along the handlebar shall be neither too tight nor too loose and do not interface with any neighboring parts at steering positions Cables shall be properly deployed wi...

Page 10: ...ompany may cause damage to engine 2 Only metric tools are valid for maintenance and repair Metric screws bolts and nuts can not be exchanged with imperial fasteners 3 New gaskets O rings cotter pins a...

Page 11: ...cial tools for disassembling assembling engine parts are as follows Table 1 1 Name Remark Special socket spanner Clutch clamp holder Flywheel puller Feeler gauge Bearing disassembly tools Bearing asse...

Page 12: ...12 Fig 1 7 Fig 1 8 Fig 1 9 Fig 1 10 handle Fig 1 11 Fig 1 12 pliers piston Fig 1 13 Fig 1 14...

Page 13: ...ter Magnetic rack V block Dial indicator Vernier calipers Circlip pliers Screwdriver with striking cap Tool for assembling oil seal of front fork Tool for hammering seal of front fork Steering nut spa...

Page 14: ...14 Fig 1 21 Fig 1 22 Fig 1 23 Fig 1 24 Fig 1 25 Fig 1 26 Fig 1 27 Fig 1 28 2 Special tools for repairing the chassis tool for hammering seal of front fork Fig 1 29 3 Steering nut spanner...

Page 15: ...ls for electric parts Table and drawings 1 31 1 32 of special tools for testing electric parts are as follows Table 1 31 Name Remark Multimeter Ignition tester Fig 1 33 Fig 1 34 Table 1 32 continued F...

Page 16: ...12 Air filter e4 3XG Rear outer tyre 130 70 12 Rear rim 3 50 12 Capacity of gasoline tank 5 0L 0 2L Transmission gear Clutch Dry centrifugal clutch Carburetor type IIF 45 Variable speed gear Transmis...

Page 17: ...17 I D of rear brake drum mm 110mm QJ50T 21U...

Page 18: ...n Check power supply for ignition Check whether short circuit or open circuit occurs to ignition coil Check whether short circuit or open circuit occurs inside the ignition system Check whether CDI ig...

Page 19: ...ortly after startup Continue to work after startup The carburetor is blocked inside or the float is too high Startup device of carburetor startup enrichment system is at fault 1 Check leakage on outer...

Page 20: ...iving Check cooling system Air cooled engine Check whether heat sink is spotted or there is too much oil stain Clean Check whether cooling fan or air director is damaged forcedly air cooled engine Ins...

Page 21: ...is blocked 2 Check whether the startup device for carburetor startup enrichment system works normally 3 Check whether the carburetor float is too low Normal combustible gas mixture Check whether the c...

Page 22: ...3 Check abrasion of the piston ring and the cylinder Start the engine and slowly accelerate observe the rotation speed change of engine The rotation speed of engine rises as it slowly accelerates The...

Page 23: ...control cable is flexible when being pulled and whether the throttle valve spring is too soft 1 Check whether CDI ignition device is in good condition 2 Check whether flywheels and trigger coil are lo...

Page 24: ...al pressure Inflate as required Check whether oil leakage occurs in fuel tank fuel switch fuel pipe or carburetor Solve problems based on actual situation Check the proportion of mixed combustible gas...

Page 25: ...justment Check whether it is coordinated when shifting Check whether the clutch is completely released Improve operation Check whether the gearshift shaft is deformed or the gearshift arm is deformed...

Page 26: ...itioning wheel spring is ruptured or lacks elasticity Replacement Disassemble crankcase and check whether the engagement depth for each gear is in accordance with requirements Proper depth in engaging...

Page 27: ...s The brake arm works flexibly but you can feel resistance when griping the lever The brake arm works inflexibly The indication arrow on the brake cam points to or beyond the sign on the brake hub cov...

Page 28: ...No voltage Voltage available Open circuit between the connector and the battery Check whether the rectifier or the rectifier regulator is broken down with an ohm meter Remove the connector between the...

Page 29: ...rt circuit Short circuit between the rectifier or the rectifier regulator or the battery and the ignition switch Replace the charging coil 1 Check whether the battery electrolyte is enough 2 Check whe...

Page 30: ...ection The starter motor works normally after short circuit The starter motor does not work after connection and there is no sound from starter relay The starter motor does not work after short circui...

Page 31: ...e the lead wires connecting to starter motor and battery from the starter relay and press the starting button Check whether the resistance between the battery terminal and the starter motor terminal i...

Page 32: ...he horn can make loud sound and the steering lamp is light The horn can not make loud sound and the steering lamp is not light Normal battery power supply Rapidly strike a lead wire on the negative po...

Page 33: ...ttery 3 Check whether the electrolyte density inside the battery is too low 4 Remove the connector between the rectifier regulator and the cable assembly check whether there is open circuit between th...

Page 34: ...tness of lamps The lamp works normally Still weak light from the lamp Low stable voltage of rectifier regulator Check whether there is short circuit in the charging coil of electromagnetic coil and th...

Page 35: ...rn button and check whether the horn works normally The horn makes loud sound The horn can not make or makes coarse sound Normal battery power supply Battery power supply shortage Remove the steering...

Page 36: ...e terminal of the electric horn and strike the power cord with the earth check the spark Spark available No spark Connect to the power cord of electric horn use a screwdriver to contact the non power...

Page 37: ...switch or brake lamp switch Power shortage of battery Check whether the brake lamp is always light Adjust or replace the brake lamp switch Leakage current is lower than the required value Leakage cur...

Page 38: ...gnition timing Bolt nut fastener Rim tyre Tyre specification Preparing Principles General Warning Make sure that it is well ventilated before starting the engine It is forbidden to start it in a close...

Page 39: ...im 3 50 12 Torque value Locking nut for front wheel spindle 55 62 N m Fixing nut for rear wheel 100 113 N m Certification for Related Parts Type Name Certificate No Remark Tyre Front outer tyre E11 75...

Page 40: ...ection I I Ordi nary tool s I I I Densimeter multimeter Actuation gap inspection I I I I I I Ordinary tools Inspection of steering handle fastening I I I Ordinary tools Absorber working inspection I I...

Page 41: ...r motorcycle inspected and adjusted periodically at Qianjiang distributors for being in best condition The above table is established under the presupposition of 1000 km month I Inspection A Adjustmen...

Page 42: ...uretor side Loosen the fixing nut and then rotate the adjusting nut for adjustment Air filter Filter replacement Remove the body guard Remove the fixing screws of air filter Remove the top cap of air...

Page 43: ...ap Note For the installation of spark plug it shall be installed with hand first and then fastened with spark plug sleeve Battery Battery disassembly Remove the fixing screws of the battery box cover...

Page 44: ...3 1V Insufficient charging 12 3V Note Use a voltmeter to check the charging condition Charging Connection the positive pole of the charger to the positive pole of the battery the negative pole of the...

Page 45: ...engine and connect the engine rotary meter Adjust the adjusting screws of the throttle cable Idle speed 1800 100rpm min When it rotates unstably at idle speed or it is unsmooth during oil filling slig...

Page 46: ...ure the cylinder pressure When compression pressure is too high please check whether there is too much carbon fouling inside the combustion chamber and at piston head Gear Oil Inspection Note Set the...

Page 47: ...Drive Belt Remove the cover of left crankcase Check whether the drive belt is ruptured or abraded Periodically maintenance shall be guaranteed and replace the drive belt if necessary drive belt Free S...

Page 48: ...r below the arrow in the picture certain brake fluid shall be added until it reaches the upper limit Note The fuel pump assembly shall be parallel with the ground during inspection Headlamp Remove the...

Page 49: ...upwards or downwards for check Check whether there is oil leakage in the front absorber and whether any component is damaged or loosened compress upwards or downwards Rear Compress the rear absorber...

Page 50: ...t outer tyre 120 70 12 Front rim 3 50 12 Rear outer tyre 130 70 12 Rear rim 3 50 12 Check whether the locking nut of the front wheel spindle is loose Check whether the fixing nut of the rear wheel is...

Page 51: ...Rotate the front wheel and move the handlebar freely for check If the handlear moves unsmoothly check the steering stem bearing when loosening Inspection and Maintenance of Electrical System Table of...

Page 52: ...52 Clutch cover bolt of the startup motor Clutch fixing nut of the startup motor Rectifier bolt High voltage coil fixing bolt Flywheel fixing nut Body guard bolt 12 95 5 0 9 0 5 0 9 0 Charging System...

Page 53: ...53 1 12V 3AH battery 2 seat lock 3 horn 4 rectifier 5 power lock assembly 6 CDI igniter 7 relay 8 release resistance 9 flasher charging system...

Page 54: ...re overvoltage inside the battery will shorten its service life 3 The battery will be self discharged if being stored for a long time which reduces its capacity It shall be charged about every three m...

Page 55: ...ifier bolt 5 0 N m Universal fixing spanner High voltage coil fixing bolt 9 0 N m Flywheel remover Flywheel fixing nut 5 0 N m Test instrument Body guard bolt 9 0 N m Multimeter 1 2 Failure diagnosis...

Page 56: ...vehicle Check the charging condition closed circuit voltage Open the battery cover and remove the battery plate assembly Remove cables to the battery connectors Measure voltage between battery termin...

Page 57: ...main switch or in the main wire in the case of any abnormality 1 4 2 Charging Check Use a multimeter to check the charging status of the battery when it is being fully charged Install the fully charg...

Page 58: ...1 white 2 and white 3 Certain numerical values will display on the pointer gauge otherwise the voltage regulator is damaged and needs to be replaced 3 Connect the red probe to the black terminal of th...

Page 59: ...of the magnetor Measure impedance between the green red coil of the magnetor bolt cooling fan Standard 2 0 2 5 20 Replace the magnetor coil when the measured value exceeds the standard value 1 7 2 Di...

Page 60: ...part of the flywheel Install the solid key into the groove above the upper crankshaft key and confirm it Aim the groove in the flywheel at the solid key on the shaft bolt Note Ensure there is no any b...

Page 61: ...2V 4AH battery 2 FBT assembly 3 rectifieer 4 power lock assembly 5 CDI igniter 6 starter relay 7 seat lock assembly 8 horn electronic igniters magnetor ignition coil sparl plug ignition system R B BL...

Page 62: ...ly 5 Failure of the ignition system is mostly caused by poor contact of the socket Check whether each connector is in good condition 6 Check whether the heat value used for the spark plug is proper If...

Page 63: ...ster Poor main switch Poor contact of CDI terminal Short circuit or poor contact of the GND of CDI Poor contact of charging coil measured at the maximum voltage Poor trigger measured at the maximum vo...

Page 64: ...rs with different impedances and different test values Connect a high pressure shunt or an ammeter with an input impedance above 10M 10CV to the multimeter 2 3 1 Primary voltage of the ignition coil I...

Page 65: ...DI CDI group black blue white Note Never touch any metal part of the test rod with your finger to avoid electric shock When the maximum voltage measured at the terminal of CDI Group is abnormal disman...

Page 66: ...primary coil with black white terminal Note Install the primary coil with black white terminal 2 5 2 Check the Primary Coil Measure impedance between terminals of the primary coil Standard 0 4 10 20 I...

Page 67: ...dy guard Remove the trigger terminal Measure the impedance between the blue white terminals of the side wire of the engine and the body GND Standard 100 200 20 Replace the magnetor if the measured val...

Page 68: ...SWITCH BRAKE SWITCH STARTER SWITCH STARTOR MOTOR Startup System 1 12V 3AH battery 2 seat lock assembly 3 horn 4 rectifier 5 power lock assembly 6 CDIigniter 7 starting relay 8 release resistance 9 fla...

Page 69: ...utch please comply with related regulations Preparing principles Item Standard Limit for use Length of the brush of the startup motor 12 5mm 8 5mm Bushing of the startup idler shaft 8 3mm Outer diamet...

Page 70: ...act Poor startup motor 3 3 Startup Motor 3 3 1 Disassembly Note Before the startup motor is disassembled turn off the main switch remove the GND wire of the battery and then power on to check whether...

Page 71: ...edle bearing inside the front cover and whether it is loose when press in Replace it if there is any abnormality Check whether the oil seal is abraded or damaged 3 3 4 Assembly Lubricate the oil seal...

Page 72: ...r relay Set up the main stand and measure voltage between the negative pole of the green yellow wire of the starter relay terminal and the body ground connection When the main switch is on hold the br...

Page 73: ...o the battery and the terminal of the startup motor to the multimeter Connect fully charged battery between the black wire and the green yellow wire of the relay The relay shall sound click and the mu...

Page 74: ...ssembly 6 right rearview mirror assembly 7 tail lamp 8 rear left steering lamp 9 rear right steering lamp 10 A Iden No of headlamp E11 005097 B Iden No of front steering lamp E11 50R 001555 E3 00 C Id...

Page 75: ...move the switch from the vehicle to measure its conduction 4 2 Failure Diagnosis When the main switch ON is not light it is due to Poor bulbs Poor switch Bad contact or broken wires 4 3 Replacement of...

Page 76: ...f tail lamp bulbs 4 5 1 Disassembly Remove the seat Remove the fixing screws of rear left right guard for dismantling the lamp shade Disconnect the tail lamp connector Remove the rear left right guard...

Page 77: ...e odometer Install the odometer in reverse order 4 7 Main Switch 4 7 1 Check Remove the front guard Remove the foot guard Remove the main switch lead terminal Check conduction of the terminal wiring d...

Page 78: ...he battery 4 9 Handlebar Switch Remove the left right rearview mirror assembly Remove the fixing screws of the left right combined switch Loosen the left right combined switch Remove the right grip as...

Page 79: ...ing bolt Fixing screw of muffler decorating shade Fixing bolt of handlebar weld assembly Front wheel spindle locking nut Front absorber fixing bolt Rear wheel fixing nut Rear absorber top nut Rear abs...

Page 80: ...pump assembly 2 brake assembly 3 oil cup pad 4 fuel pump gasket 5 oil cup cap 6 screw M4 10 7 fixing cover 8 bolt M6 23 9 fuel pump body 10 connecting bolt 11 gasket 12 brake hose assembly 13 nut M6...

Page 81: ...r 9 rear brake camshaft 10 rear brake return spring 11 rear brake swing arm assembly 12 rear swing arm mounting bolt 13 o ring 14 dust cover A Torque for mounting nut 5 100 113N m B I D of brake drum...

Page 82: ...ion disc 3 0 2 0 Diameter of front brake disc 190 I D of rear brake drum 110 Thickness of rear brake shoe 4 0 3 0 5 1 2 Torque Force Fixing bolts for fuel pump assembly 5 9 N m Mounting bolts for fron...

Page 83: ...k it before disassembly so as to reinstall it at the original place Remove following assemblies from the right grip and the front absorber Front brake 1 brake handle 17 2 fuel pump assembly 1 3 brake...

Page 84: ...thin the motorcycle without removing down 5 3 3 Installation Install the front brake disc and the front wheel Install the front brake hose assembly and the brake cylinder assembly Do not stain the fri...

Page 85: ...heel fixing nuts 4 rear indicator 5 rear brake return spring 6 rear brake camshaft 7 brake shoe assembly 8 brake shoe spring 9 tubeless tire 130 70 12 10 rear rim Note for breakdown details see P78 5...

Page 86: ...ts and nuts to the required torque force Torque force Fixing nuts for rear wheel 100 113 N m Do not stain brake shoes and brake disc with oil spots Use brake cleaning agent to clean brake shoes and br...

Page 87: ...cover of handlebar front shade 16 front shield 17 tapping screw ST4 2 16 18 front fender bracket 2 19 headlamp 20helmet hook 21 frame number cover 22 foot protection board 23 foot pedal 24 tail lamp 2...

Page 88: ...onnecting bracket of the left right guard rear connecting bracket of the left right guard left right guard left right guard lower connecting bracket battery cover foot pedal taillight rear license pla...

Page 89: ...5 middle spindle sleeve assembly 6 front rim 7 tubeless tyre 120 70 12 8 gear housing assembly 9 nut M12 1 25 10 valve cap 11 valve A Tyre size outer tyre 120 70 12 Auth No of the front wheel outer t...

Page 90: ...piece cup 7 steel ball 5 8 upper cup of the lower bearing 9 lower cup of the lower bearing 10 odometer cable clamp 11 bolt M6 12 12 brake cable clamp 2 13 brake cable clamp 1 14 bolt M10 1 25 30 15 bo...

Page 91: ...left rearview mirror assembly 11 right rearview mirror 12 left combined switch 13 left handle 14 handle set screw M5 15 nut M5 16 right combined switch 17 flat screw M5 20 18 throttle cable jacket A...

Page 92: ...hall not be stained with grease during operation Motorcycle Standards Measurement points Item Standard value mm Limit for use mm Front wheel spindle Bending 0 2 Front wheel Rim shimmy Vertically 2 0 H...

Page 93: ...the absorber 7 3 Front Wheel 7 3 1 Disassembly Note Support the motorcycle firmly Loosen the mounting bolts of the brake cylinder assembly Remove the brake cylinder assembly Place a proper holder unde...

Page 94: ...earing Remove the front wheel spindle and the front brake disc Remove the left bushing and the oil seal of the front wheel Remove the bearing Check rolling of the bearings The bearings will not roll i...

Page 95: ...front wheel spindle shown in the right picture Note for the disassembly and assembly of the front suspension of QJ50T 21U please see P86 Torque force Locking nuts for the front wheel spindle 55 62 N m...

Page 96: ...for the steering handle weld assembly Fixing nut spanner Special disassembly tool for bearing cup Note The opening of the body guard shall be cleaned with cloth The upper lower bearing cup shall be di...

Page 97: ...97 Install the left right absorber assembly Install the handlebar Install the body guard Install the front wheel Note for the disassembly and assembly of the front fork of QJ50T 21U please see P87...

Page 98: ...r brake camshaft 10 rear brake return spring 11 rear brake swing arm 12 rear swing arm mounting bolt 13 o ring 14 bolt M10 1 25 40 15 rear absorber assembly A Torque for fixing nut 5 of the rear wheel...

Page 99: ...ear indicator 9 rear brake camshaft 10 rear brake return spring 11 rear brake swing arm assembly 12 rear swing arm mounting bolt 13 camshaft O ring A Tyre size 130 70 12 B Rim size 3 50 12 C Rim run o...

Page 100: ...l spots Preparing Principles Item Standard mm Limit for use mm Rear wheel shimmy Vertically 2 0 Horizontally 2 0 Locking torque force Fixing nuts for the rear wheel 100 113 N m Fixing bolts of rear ab...

Page 101: ...re the eccentricity ratio with a dial indicator Limit for use Vertically replacement when beyond 2 0mm Horizontally replacement when beyond 2 0mm When the rear wheel shimmy exceeds the limit the rear...

Page 102: ...rear fender Remove fixing bolts of the rear absorber Remove the rear absorber 8 4 2 Installation Installation of the rear absorber Torque force Upper fixing nut 37 44 N m Lower fixing nut 22 29 N m I...

Page 103: ...mic hanger weld assembly 7 seat assembly 8 fuel tank assembly 9 seat lock assembly 10 bolt M6 20 11 rear storage box rack holder 12 bolt M6 12 13 seat cable 14 rebite 3 2 7 A Note for the disassembly...

Page 104: ...ng 6 clamp 4X 8X360mm 8 clamp 7 9 fuel tube 2 4 5X 8 5X250mm 10 filter assembly 11 oil level sensor 12 bolt M5 16 13 oil level sensor gasket 14 sealing rubber 15 filter jacket 16 filter element A Gaso...

Page 105: ...nut M6 5 rubber buffer block 6 helmet box 7 bolt M6 16 8 helmet box base cover 9 rear rack 10 washer 8 11 bolt M8 45 12 O ring 13 tapping screw ST4 8 16 14 anti modification plate A Torque for bolt 4...

Page 106: ...and screws to the required torque value for assembly After assembly check whether all the parts are correctly installed and operated Preparing Principles Item Standard Limit for use Gasoline tank capa...

Page 107: ...k Remove the rear left right guard assembly Remove the rear rack and helmet box Remove the rear rack holder Turn the fuel switch to OFF Disconnect the fuel hose Remove the fuel tank Note For details s...

Page 108: ...280 2 bolt M10 1 25 40 3 seat steel rope 4 bolt M8 31 5 rear shock absorber assembly 6 engine assembly 7 rear wheel assembly 8 rear brake rocker arm assembly A torque force of engine stationary axis 1...

Page 109: ...emoved Preparation standard Motor is not only kinetic resource of motorcycle but also driving part and main rear suspension device On one hand the motor with rotating action output by crankshaft getti...

Page 110: ...ve the right suspension bolt and gasket Remove the left suspension bolt Remove the engine from the frame 10 3 2 Motor Suspension Standing Clamp 10 3 2 1 Disassembly Remove spark plug cap Remove fuel t...

Page 111: ...ll bolt and nut of engine suspension temporarily 10 4 Installation Install according to reversed procedures of disassembly Note For details see P104 Torsion value of installation engine stationary axl...

Page 112: ...nder double head Motor fixing bolt Locking screw for the crankcase left cover shade Locking bolt for the crankcase left cover Locking nut for the drive wheel Locking nut for the driven wheel Locking n...

Page 113: ...gears and worm wheels shall rotate flexibly without being seized or imbalanced tightening A little axial movement shall be allowed for worm wheels Fuel pump O ring shall not cut the edge Machine oil...

Page 114: ...ubrication system is to supply lubricant to component surface transforming the dry friction on the surface to liquid friction among the lubricant particles in order to reduce wear of the components co...

Page 115: ...s director assembly gas director Loose screws on fan and remove fan fan screw Remove magnetogenerator stator rotor and support Magnetogenerator stator rotor and support Remove worm wheel from cranksha...

Page 116: ...according to reversed procedures of removal 11 3 3 Check Check whether worm wheel teeth are damaged or whether key slot is damaged Measure plunger OD Permitted limit 2 61mm Machine oil pump cap Fuel...

Page 117: ...5 float pin 6 main metering jet 7 idling jet 8 main foam pipe 9 idle adjusting screw Note Gasoline is very dangerous Fire is strictly forbidden in workplace After the carburetor is disassembled block...

Page 118: ...since it may block the idling jet after deterioration which affects idle speed Carburetor functions Carburetor is a critical component in the fuel supply system of the engine its work condition direc...

Page 119: ...m Too dense mixed gas Interrupted spark at acceleration Abnormal enrichment valve Too dilute mixed gas Abnormal needle valve Over high oil level Oil spilling from the carburetor Blocked air channel Di...

Page 120: ...ce it if abraded Check abrasion of oil needle Replace it if abraded Loosen screws and remove the float chamber Remove the float assembly float pin and needle valve assembly 12 3 3 Check Check whether...

Page 121: ...rm up for about 3 minutes to make the engine run at normal driving temperature Adjust the idle adjusting screw to make the engine run at 1800rpm Tighten the mixture adjusting screw to the extreme with...

Page 122: ...plug 2 fixing bolt of cylinder cover 3 cylinder cover 4 cylinder gasket 5 cylinder Note The cylinder cover bears large bolt pretension to ensure sealing between the cylinder cover and the cylinder bod...

Page 123: ...k Function of the cylinder cover the cylinder cover is used to seal the cylinder and form the combustion chamber with the piston It bears HPHT gas and achieves air intake and exhaust through distribut...

Page 124: ...3 4 Cylinder Cover Check Check whether cylinder cover is broken Check flarness of cylinder cover bottom surface Limit for use 0 04mm 13 5 Installation of Cylinder Cover Install it in reverse order Fix...

Page 125: ...125 Cylinder Block and Piston 1 piston 2 piston pin 3 cylinder block 4 cylinder gasket 5 cylinder cover 6 nut 7 spark plug Note all parts shall be cleaned and blown by high pressure air before check...

Page 126: ...the crankshaft It forms combustion chamber along with the cylinder cover It acts as slide valve for air inlet stop periodically compresses fresh mixed gas from the crankcase into the cylinder and dis...

Page 127: ...kcase leakage Over high compression pressure Abnormal noise of the piston Too much carbon deposit in the combustion chamber Damaged cylinder piston or piston ring Abrasive piston pin hole and piston p...

Page 128: ...the piston ring Note Do not rupture or damage the piston ring Eliminate carbon deposit in the groove of the piston ring Remove the piston ring and install each piston ring on the cylinder bottom Note...

Page 129: ...t is at 90 degree with the piston pin Measure the inner diameter of the cylinder at the top middle and bottom points Limit for use 40 05mm Measure the maximum clearance between the cylinder and the pi...

Page 130: ...rotate freely in the piston ring groove Remove any residual spacer attached to the crankcase Note Do not make any object fall into the crankcase Install the piston piston pin and retainer ring Note Th...

Page 131: ...t 2 spring 3 friction plate 4 check ring Note During operation the surface of the triangle belt can not be stained with any grease which must be removed It helps avoid slipping between the triangle be...

Page 132: ...4 idler shaft 5 start shaft assembly 6 kickstart shaft spring Note During operation the surface of the triangle belt can not be stained with any grease which must be removed It helps avoid slipping be...

Page 133: ...Unit mm Item Standard Limit for use Inner diameter of right half driven wheel 25 989 26 052 26 06 Outer diameter of the sliding sleeve 25 96 25 974 25 94 Width of the triangle belt 17 16 Thickness of...

Page 134: ...nuts for drive face and the left half drive face Remove the triangle belt from the drive face Check whether the triangle belt is cracked and whether rubber or cotton yarn falls down or is abnormally...

Page 135: ...e the right half drive wheel assembly 15 4 2 Breakdown of Right half Drive Wheel Assembly Check abrasion of the ball Measure the outer diameter of the ball Limit for use 14 4mm Right half drive wheel...

Page 136: ...1 Disassembly Install the clutch sleeve with the fixer and remove fixing nuts Remove the clutch sleeve clutch driven wheel driven wheel clutch sleeve fixer socket spanner 15 5 2 Breakdown of Clutch Re...

Page 137: ...6 Breakdown of Clutch and Driven Wheel Clutch spring compressor must be used for disassembling the clutch spring Note Spring compressor must be used for disassembly to avoid damage to spring Install t...

Page 138: ...er of the bushing on the right half driven wheel Limit for use 32 94mm Measure the inner diameter of the sliding sleeve on the left half driven wheel Limit for use 33 06mm 15 6 1 Replacement of the Be...

Page 139: ...e elastic retainer ring Install the needle bearing Press the needle bearing in with the equipment shown in the picture 15 6 2 Combination of Clutch and Driven Wheel Eliminate any grease on the surface...

Page 140: ...ked grease spring guard Install the clutch spring and the clutch on the driven wheel Compress the set with the clutch spring Install locking nuts after compression Note Properly compress the spring to...

Page 141: ...bly Remove the start shaft assembly Check abrasion of the start shaft Check abrasion of stress area of the start shaft sleeve and the idler shaft Check abrasion of idle gear Measure clamping force of...

Page 142: ...rator 1 middle gear 2 middle shaft 3 main shaft of clutch 4 output shaft gear 5 bearing 6 oil seal 7 bolt 8 gasket 9 gear room cover Function transfer torque and decide final output torque and rotatio...

Page 143: ...ecide final output torque and rotational speed 16 2 Failure Diagnosis No run after engine startup Broken driving gear Burnt driving gear Leaked gear oil Too much gear oil Damaged oil seal 16 3 Gearbox...

Page 144: ...he gearbox cover Note Removed bearing cannot be used any more It shall be replaced Use special tools to dismantle the bearing and the oil seal Remove the oil seal from the gearbox and knock the bearin...

Page 145: ...The crankcase is thin section casting thus shall not suffer impact during operation which may cause deformation or fracture All components must be cleaned and blown with high pressure gas before test...

Page 146: ...ort the crankshaft clutch gearbox cylinder block and cylinder cover sustain combustion shock and inertia force from the movement of the connecting rod and form part of closed space oil sealing gas sea...

Page 147: ...emove starting driving gear Remove star gear Remove crankcase standing bolt Remove left and right crankcase Note Gasket shall not be damaged Remove gaket location pin Remove crankshaft from crankcase...

Page 148: ...ve oil seal from right crankcase 17 3 2 Check Right left clearance of connecting rod big end Usage limit 0 6mm Measuring location of connecting rod Clearance between X Y orientation of connecting rod...

Page 149: ...condition replace the crankshaft component Note Oil seal disassembled shall not be used again Use special tools to remove oil seal 17 4 Installation Assemble crankcase according to reversed sequence...

Page 150: ...ge gasket 8 housing unit 9 exhaust pipe front section 10 graphite wound gasket 11 nut M6 12 connecting flange gasket 13 bolt M8 20 14 bolt M6 16 15 screw M6 25 16 screw without head M6 25 17 gasket 6m...

Page 151: ...t emission standards and also make great effort in purifying air and reducing pollution This motorcycle has been strictly examined before delivery and is in conformity with all exhaust emission standa...

Page 152: ...rburetor adjustment etc 18 3 Mechanical Function of the Exhaust Control System General This system adopts two stroke single cylinder engine carburetor and air conduction device to maintain qualified e...

Page 153: ...because of high temperature 2 Motorcycles with catalytic converter shall not be near flammable material 3 There is CO inside the exhaust pipe which is harmful to health So do not run the engine in cl...

Page 154: ...engine Valve leakage Piston abrasive Combustor cleaning Qualified for delivery Qualified Qualified Qualified Qualified Qualified 18 5 Measures when the idle speed emission value exceeds the standard T...

Page 155: ...155...

Page 156: ...Gas sensor Cable color Temperature controller interface Release resistance Front right turn light Head light Night lamp Front left turn light Electric horn Rear right turn light Tail light Rear left...

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KEEWAY QJ50T-21U, Maintenance Manual

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