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YG125-30A    Maintenance Manual

 

                                                        Front wheel, front overhang and steering stem 

 

 

113 

2mm) 

Speedometer 

gear box 

Gear is damaged

     

The indicator of the 
speedometer fails to move 

Replace 
speedometer 

gear 

box   

The gear drive 
ring is damaged

   

 

Maintenance of Front Shock Absorber 

Component 

description 

Damage form 

Trouble symptom of 
component 

Trouble symptom of 

        motorcycle 

Repair method 

Front shock 
absorber 
spring   

The elastic force is 
Insufficient or 
broken   

The elastic force of 
shock absorber is 

Insufficient or broken     

Front shock absorber is over 

Soft, abnormal sound comes 
out in case of front absorber 
working   

Replace front shock 
absorber spring   

Front shock 
strut   

Bending and 
deformation   

Front shock strut is bent 
and deformed   

Off-track in running   

Correct or replace 
front 

shock strut   

Working stroke 
surface is damaged 
or scratched   

Leakage from oil seal   

Leakage at front shock 
cylinder   

Replace front shock 
strut   

Working stroke 
surface Cr coating 
partial is worn out 
to expose the 
substrate   

Leakage from oil seal   

Leakage at front shock 
cylinder   

Replace front shock 
strut   

Front shock 
cylinder   

Broken deformed 
and damaged   

Leakage at front shock 
cylinder   

Leakage at front shock 
cylinder   

Replace front shock 
cylinder   

Piston rod 

Over worn or 
damaged   

 

Over soft at front shock 
cylinder   

Replace piston rod   

Piston ring is over 
worn or damaged   

 

Over soft at front shock 
cylinder   

Replace piston ring   

Oil sealing   

Cut edge is over 
Worn or damaged 
or aged 

Leakage from oil seal 

Leakage at front shock 
absorber 

Replace oil seal   

Shock oil   

Insufficient oil 
amount or too little   

Insufficient shock oil or 
too 

little   

Over soft of front shock 
absorber   

Fill shock oil as per 
the specified stipulate   

 
Maintenance of Steering Post 

Component 
description 

Damage form 

Trouble symptom 
of    component 

Trouble symptom of 
motorcycle 

Repair method 

Steel ball 
socket 

Over tight of steering 
stem screw   

Too small gap 
between steel ball 
and steel ball 
steering ring   

Steering handle is 
ineffective.   

Adjust the steering 
post screw by tighten 
wrench till the 
steering post moves 
left and right flexibly 
and no axial shifting 
between steering post 
and frame stand pipe   

Over worn, pockmark, 
indentation, crack and 
damage of steel ball 
steering ring ball track   

 

Ineffective steering handle 
or handle shakes or vibrates 
during running   

Replace complete 
steel ball steering ring   

Steel ball   

The steel ball is worn, 
deformed and 
damaged.   

 

Ineffective handle steering 
or handle shakes or vibrates 
during running   

Replace all steel balls   

Steering stem    The steering stem is 

deformed   

The steering stem is 
deformed.   

The steering stem is 
deformed.   

Replace steering 
stem 

https://www.motomanuals.net/

Summary of Contents for YG125-30A

Page 1: ...1 Maintenance Manual YG125 30A Chongqing YINGANG technology group co LTD https www motomanuals net...

Page 2: ...ge the distributor will be informed in advance and the content of the change will be reprinted Note Specifications and designs are subject to minor changes without prior notice Symbol description warn...

Page 3: ...d starting system 79 2 6 Crankcase crankshaft and Shift mechanism 88 Chapter 3 Vehicle body 105 3 1 Frame and exhaust system 105 3 2 Front wheel front overhang and steering stem 110 3 3 Rear wheel and...

Page 4: ...l About Motorcycle Maintenance Maintenance Period Table Technical Data of Main Performance Symbol Descriptions Standard Torque Values Engine Number Position Photo of Complete Vehicle Frame Number Posi...

Page 5: ...s After reassembling check whether all the spare parts are mounted properly by means of turning moving and operating them 4 To disassemble and assemble a motorcycle special service tools SST and gener...

Page 6: ...sure the terminals are not too long or are falling off The connector shall be fully inserted in place For a connector with lock confirm whether the lock is completely fixed Make sure the harness is n...

Page 7: ...dy The wire harness shall be incapable of passing through the position contacting a bolt a screw head or any front part The wire harness shall not be slackened or be forcibly pulled If the wire harnes...

Page 8: ...after understanding the explanations in the instruction manual 16 Do not drop or throw the parts and components 17 In case of rust on the terminals carry out connection operation after disposing it w...

Page 9: ...80 17 Normally loaded 225 kPa Normally loaded 225 kPa Single disc type Model 276 Single disc type Model 220 12L 93 Engine Mode Cylinder bore Stroke Cylinder displacement Compression ratio Max power M...

Page 10: ...Sequence I N V Electrical system Electric generator Accumulator capacity Power supply system Fusible cutout Spark plug Spark plug gap Ignition coil type Fuel supply mode Ignition mode Ignition advance...

Page 11: ...TITE 648 Stator leads pressure plate bolt 2 6 8 12 LOCTITE 648 Spark Plug 1 12 18 25 Pensioner plate fastening bolt 1 6 7 10 Vehicle body Item Quantity Thread diameter mm Torque value N m Thread locke...

Page 12: ...special power tool for mantling dismantling bolt and nut Pawl socket for mantling dismantling oil filtering element nut and clutch nut A and B bolt socket for mantling dismantling A and B bolt and ex...

Page 13: ...ance of piston cylinder valve etc Micrometer to measure the dimensions of piston piston pin etc Dial gauge to measure the wheel bouncing cylinder inner diameter etc Cylinder barometer to measure the c...

Page 14: ...fastening I I I I Wheel tire I I I I Steering column bearing I I I I Steering backstay cable Inspect every 5000km driving and replace every 10000km driving Maintenance shall be carried out to the moto...

Page 15: ...rpose tools Tightening torque of 50 N m Use suggested engine oil Use the mixtures of engine oil and molybdenum disulfide Use thread locker Use sealant Use lithium base grease 1 Measures to be prompted...

Page 16: ...y scale must reach Grade SG and its viscosity shall be selected according to the accompanying diagram depending upon region and air temperature changes While replacing lubricating oil fully discharge...

Page 17: ...diagram besides applying dedicated lubricating oil for chain to the driving chain apply lithium base grease to all other positions All lubricating oils not specified for use in this manual shall be o...

Page 18: ...system 16 Engine Lubrication System Diagram Crankshaft oil through Spindle oil through Countershaft oil through Camshaft oil through Cylinder head oil through Cylinder oil through Oil filter Oil pump...

Page 19: ...g and discharge the waste engine oil and then clean the oil drain plug engine oil strainer engine oil filter etc Finally insert the oil drain plug Unscrew the oil filter plug and slowly refill 1 8L ne...

Page 20: ...g to the method of Replacement of Lubricating Oil Cleaning and Replacement of Lubricating Oil Filter Remove the engine oil filter cover to detach the engine oil filter element clean the filter cover a...

Page 21: ...embly of oil pump etc Steps for oil pump removal 1 Remove the oil drain plug to drain the engine oil inside the crankcase 2 Loosen the right crankcase cover connecting bolts to detach the right crankc...

Page 22: ...with new ones 6 Remember to refill engine oil after all these are completed CAUTION The clutch retaining nut must be screwed up to the specified tightening torque must be applied to prevent the nut fr...

Page 23: ...organs of human being The way is simple and easy to use it is used wide in motorcycle maintenance Testing examination method This way is a way that test the size of part and change of geometric form...

Page 24: ...ing to the contents hereof before using it Technical specifications Throttle bar free stroke 1 3mm Recommended spark plug CPR8EA 9 Spark plug gap 0 7 0 9mm Valve clearance cold IN 0 06 0 08mm EX 0 06...

Page 25: ...d condition To mount the spark plug manually screw up the spark plug first and then tighten it with a socket wrench Put on the spark plug cap Lubricating oil Park the motorcycle on a flat surface let...

Page 26: ...should check electronic ignition high voltage coil charging on the generator and trigger coil etc After properly timing pull off the tensioner locking key and coat the mixture of engine oil and molybd...

Page 27: ...t indicates insufficient tension of the chain tensioner replace it with a new one To replace the chain tensioner Unscrew the 2 M6 16 socket cap screw to remove the sealing washer and detach the old ch...

Page 28: ...arms will move apparently when flywheel rotate a small angle the flywheel is not in the compressing stroke but exhaust intake stroke In this case continuously turn the flywheel clockwise for 360 degr...

Page 29: ...Since the intake flow at idle speed has been properly adjusted upon delivery do not adjust the idle speed adjusting screw as desired In case the idle speed is unsteady zero or too high find out the p...

Page 30: ...ubber lagging Coarse adjustment If the fine adjustment is not satisfying separate the throttle control line with throttle valve body and unscrew the retaining nut B to make adjust the free stroke in a...

Page 31: ...screw the deflating valve bolt with the torque being 7 9 N m 6 Mount the brake cylinder cover with the sealing gasket flattened and replace with new sealing gasket as required 7 After refilling check...

Page 32: ...special maintenance station And it is better to use the parts from our company Caution Please change the brake shoe in time if it has been touched the wear limit Otherwise it would cause accidents by...

Page 33: ...it according to the following overhauling content The content is the free stroke of clutch control handle general is 10 20mm some venial need adjust the adjusting screw of declutch mechanism Check th...

Page 34: ...f the chain is too loose or too tight make adjustment Adjusting methods Unscrew the rear wheel spindle nut and turn the adjusting bolt on the chain adjuster until the specified tension is achieved and...

Page 35: ...charge it with a charge power supply Seriously corroded conductor connectors of the battery shall be replaced Installation of accumulator Installation is in the reverse order of removal While connecti...

Page 36: ...p While installing the rear brake spring shall be reliably hooked with the pin hole on the rear brake lamp switch After replacement adjustment shall still be carried out to the rear brake lamp switch...

Page 37: ...clockwise Install new bulb in opposite order as below Taillight bulb 12V 9W 3W Front and rear lamp bulb Loosen the screws remove the lamp lampshade Lightly press bulb rotate in counter clockwise Insta...

Page 38: ...ecified torques Rear suspension Forcibly press the rear end of the seat cushion with the rear suspension and check the rear fork spindle sleeve for abrasion or damage If it is damaged replace it Check...

Page 39: ...YG125 30A Maintenance Manual Fuel system 41 4 Fuel system Fuel tank Throttle valve body Air filter Fuel pump Inlet pipe https www motomanuals net...

Page 40: ...f such sealing members as the O ring while removing various parts of the fuel system While reassembling always use new sealing members such as an O ring Technical specifications Throat opening diamete...

Page 41: ...rocedures are the removal procedures in reverse order While installing note that the wiring of the fuel pump control wire shall be in strict accordance with the wiring diagram Avoid fuel line contamin...

Page 42: ...body including the fuel injector Installation steps The installation procedures are the removal procedures in reverse order While installing the locating slot must be aligned with the locating lobe o...

Page 43: ...osit on the filtering element The engine is difficult to start Insufficient engine output Poor performance of engine during idle run Excessive fuel consumption The exhaust muffler pipe fumes strongly...

Page 44: ...YG125 30A Maintenance Manual Removal and installation of engine 46 5 Removal and installation of engine https www motomanuals net...

Page 45: ...intain the heat engine parts including cylinder head cylinder body piston etc it is necessary to remove the coverings fuel tank throttle body air filter assembly etc To remove the engine s right crank...

Page 46: ...and fuel tank 3 Remove muffler 4 Remove engine cycle tube 5 Remove Left Right cylinder head connecting pipe 6 Detach the earth wire from the negative pole of the battery 7 Remove clutch cable 8 Remov...

Page 47: ...chain Remove the rear absorber and rear fork connecting bolt Unscrew the nut and take out the rear fork shaft Take out the rear fork backwards Loosen the nut and remove the lower hanging bolt Move th...

Page 48: ...YG125 30A Maintenance Manual Removal and installation of engine 50 Remove the drive chain Move the engine slowly from the right https www motomanuals net...

Page 49: ...YG125 30A Maintenance Manual Cylinder Head Cylinder and Piston 52 6 Cylinder head cylinder and piston Cylinder head cover Cylinder head Cylinder https www motomanuals net...

Page 50: ...ling coat engine oil and molybdenum disulfide lubricant on the protruding surface of the camshaft for preliminary lubrication Be careful not to damage the cylinder wall and piston Technical specificat...

Page 51: ...mall end Internal diameter 13 013mm 13 028mm 13 028mm Clearance with piston pin 0 013mm 0 033mm 0 033mm Piston ring First ring gap clearance 0 015mm 0 05mm 0 05mm Second ring gap clearance 0 015mm 0 0...

Page 52: ...ng worn Black smoke from exhaust 1 Valve guide worn 2 Oil shield leaked or damaged 3 Cylinder piston piston ring worn 4 Piston ring clearance too big 5 Piston ring incorrectly installed 6 Piston or cy...

Page 53: ...tion pin into the crankcase To mount the cylinder head cover 1 Turn the crankshaft so that the piston is at the upper dead point of the compression stroke 2 Remember to confirm the location pin 3 Moun...

Page 54: ...e the camshaft bearings 7 Strip the timing chain from the timing driven sprocket and remove the timing driven sprocket 8 Remove the camshaft Caution Do not drop the timing chain into the crankcase To...

Page 55: ...clearance 7 Connect the phase sensor and mount the eyehole cover and upper eyehole cover in turn Caution When the tensioner is not tensioned never turn the crankshaft for fear of interlocking the teet...

Page 56: ...r installation 1 Confirm the location pin clean all parts and components and check whether the cylinder head oil through is unobstructed clean and free of leak 2 Replace new cylinder head gasket 3 The...

Page 57: ...ity Remarks 1 cylinder block 1 2 Cylinder head gasket 1 Coat the mixture of engine oil and molybdenum disulfide on the stem while assembling 3 Cylinder body gasket 1 Coat the mixture of engine oil and...

Page 58: ...limit 4 53mm Measure the valve stem diameter Maintenance limit IN 5 15mm EX 5 15mm Measure the width of the valve contacting surface Maintenance limit 1 7mm Measure the free length of the valve sprin...

Page 59: ...ide gage seat Cylinder inspection Check the cylinder for abrasion or damage and check the cylinder wall for scratch Check the cylinder wall for deformation and use the edge ruler and clearance gauge t...

Page 60: ...tallation of camshaft 6 Mount the cylinder head cover See Installation of cylinder head cover Notice Assemble the piston with the top side with the marker facing exhaust side Do not drop the piston pi...

Page 61: ...mounting position of the first ring ATG marker and second ring A marker No Procedure Quantity Remarks Sequence of disassembling Assembling is in the reverse order of disassembling 1 Crank rod assembl...

Page 62: ...clearance between the piston ring and the piston groove before removing the piston ring Maintenance limit First ring Second ring 0 12mm Oil ring 0 40mm Mount the piston rings into the cylinder respec...

Page 63: ...YG125 30A Maintenance Manual Clutch and Right crankcase cover 70 Clutch and Right crankcase cover Clutch Right crankcase cove Engine https www motomanuals net...

Page 64: ...onents with cleaning agent and dry them with compressed air To assemble the clutch loosen the clutch spring and coat engine oil on the clutch disc in case of replacing new clutch the clutch disc must...

Page 65: ...1 Clutch cable galling damaged or dirty 2 Clutch push rod damaged or jammed Hard clutch operation There is burr on clutch housing chute Shift lever can t return 1 Return spring cracked or slipped 2 Tr...

Page 66: ...se cover connecting bolt 5 Take out the right crankcase cover component 6 Take out the right crankcase cover sealing paper gasket To install the right crankcase cover 1 Confirm the location pin clean...

Page 67: ...the clutch operating lever Mount the clutch operating lever rear brake return spring cotter pin rear brake lamp switch etc 6 Refill engine oil Notice Do not scrape the crankshaft oil seal Assemble onl...

Page 68: ...crankcase cover sealing paper gasket 2 Replace it with a new one while assembling 3 clutch push rod 1 4 rubber ring 1 5 Oil Level Gauge 1 6 lever return spring 1 7 elastic cylindrical pin 1 8 clutch l...

Page 69: ...the clutch 5 Remove the clutch washer To install the clutch 1 Mount the clutch washer with the sabotage side facing the main shaft right bearing 2 Mount the clutch 3 Mount the butterfly washer and re...

Page 70: ...the right crankcase cover by turning the clutch push rod until its rack side faces the crankshaft See Installation of right crankcase cover Warning Thread retaining adhesive LOCTITE243 must be coated...

Page 71: ...Bolt m6 25 4 Disassemble and assemble of clutch Disassemble and assemble the clutch according to the following diagram While removing the clutch lift plate alternatively loosen the 6connecting bolts t...

Page 72: ...val 1 clutch bush 1 Tightening torque 12N m 2 clutch assembly 1 3 Nut M14 1 1 4 Flat washer 1 5 Deep groove ball bearing 1 Gum base soaking oil while assembling 6 Clutch out cover 1 7 Clutch lug washe...

Page 73: ...3 Check the clutch plate for distortion and check the planners with a clearance gauge Maintenance limit 0 20mm 4 Measure the thickness of each clutch plate The thickness is 1 4mm 5 Measure the free l...

Page 74: ...Maintenance Manual Magneto and starting system 79 8 Magneto and starting system Engine Double linked Gear Rotor assembly Left front cover Idle gear Disk gear Double linked gear cover https www motoma...

Page 75: ...he mixture of engine oil and molybdenum disulfide onto the left crank journal as the initial lubrication Do not dent the seal surface and do not damage the stator coil Technical specifications mainten...

Page 76: ...d separate the magneto lead connector with the main cable 2 Unscrew the oil drain plug to drain the engine lubricating oil inside the engine 3 Remove the double linked gear cover connecting bolts 4 Re...

Page 77: ...bling the magneto stator connecting bolt In case of O ring aging prolonging or deforming replace it Notice Do not dent the seal surface and do not damage the stator coil No Procedure Quantity Remarks...

Page 78: ...gear etc 3 Use the rotor fastening tool to fasten the rotor and remove the fastening nut M12 and plain washer 4 Use the rotor extractor to extract the rotor 5 Remove the rotor assembly washer disk gea...

Page 79: ...ion is in the reverse order of removal 1 Screw M8 16 6 Use thread retaining adhesive LOCTITE 648 while assembling with the tightening torque being 25N m 2 One way device outer body 1 3 One way device...

Page 80: ...Washer and the double linked gear is assembled into the left crankcase 5 To install the left front cover Clean the sealing paper gasket remaining on the left crankcase and left front cover replace wit...

Page 81: ...TE 648 while assembling the pressure plate bolt Warning Thread retaining adhesive LOCTITE243 must be applied to the rotor retaining nut M12 while assembling with the tightening torque being 45N m Chec...

Page 82: ...YG125 30A Maintenance Manual Magneto and starting system 87 7 Measure the washer thickness the maintenance limit 0 4mm Vernier calipers https www motomanuals net...

Page 83: ...Manual Crankcase crankshaft and Shift mechanism 88 9 Crankcase crankshaft and Shift mechanism Right hand crankcase body Crankshaft Gearshift drum Counter shaft Main shaft Left hand crankcase body http...

Page 84: ...1 Right hand crankcase clutch gear shifter 2 Cylinder head cover camshaft cylinder head cylinder and piston See Cylinder head cylinder and piston 3 Left front cover rotor assembly electrical starting...

Page 85: ...bent or damaged 2 Shift fork shaft bent 3 Gearshift drum badly machined or bearing shifted 4 Driving driven shaft bearings shifted Gear shift trouble 1 Shift fork bent or damaged 2 Shift fork shaft be...

Page 86: ...Do not pry the left right hand crankcase body by inserting such tools as screwdrivers into the mould closing face To mount the crankcase 1 Place the right hand crankcase on the assembly operating tab...

Page 87: ...n left front cover rotor assembly electrical starting transmission system driving drive sprocket etc Refer to the related sections 6 Mount the assembled engine onto the frame and engine oil to complet...

Page 88: ...ankcase 1 2 Pin 1 3 Pad 1 4 O ring 1 5 engine oil filter net 1 6 Release oil bolt 1 7 Pad 1 8 Left hand crankcase 1 9 O ring 1 10 Double head bolt 1 11 Main gear plate 1 12 Bolt M6 16 1 13 Pin 10 14 2...

Page 89: ...g inwards No Procedure Quantity Remarks Removing order Installation is in the reverse order of removal 1 Left hand crankcase 1 Apply engine oil while assembling 2 Crankshaft bearing 6203 1 Apply engin...

Page 90: ...order Installation is in the reverse order of removal 1 Right hand crankcase 1 2 Balance shaft bearing 6302 1 Apply engine oil while assembling 3 Driving shaft bearing 62 22 C3 1 Let the oil seal side...

Page 91: ...case body crankshaft bearing until the temperature at the inner circle of the bearing reaches 106 and then assemble the crankshaft 2 Use a high power electric drier to heat the right crankcase body ba...

Page 92: ...aft and Shift mechanism 98 No Procedure Quantity Remarks Removing order Installation is in the reverse order of removal 1 Left hand crankcase 1 2 Crankshaft 1 3 Balance shaft 1 4 Right hand crankcase...

Page 93: ...g Assembling is in the reverse order of disassembling 1 Balance shaft 1 Apply engine oil while assembling 2 Driving gear 1 Apply engine oil while assembling 3 Pad 1 Apply engine oil while assembling 4...

Page 94: ...meter Maintenance limit 20 063mm 2 Measure the crankshaft radial run out Maintenance limit 0 10mm 3 Measure the connecting rod big end radial clearance Maintenance limit 0 06mm 4 Measure the connectin...

Page 95: ...iven shaft and assemble the them together 2 Assemble the shift fork with 3 Mount the gearshift drum 4 Change the O shaped sealing ring mount the shift fork and check whether the driving driven shaft c...

Page 96: ...ift fork 1 Apply engine oil while assembling 7 Shift fork right 1 Apply engine oil while assembling 8 driving shaft 1 Apply engine oil while assembling 9 driven shaft 1 Apply engine oil while assembli...

Page 97: ...e unloaded rotor assembly left crankcase assembly See Removal of left hand crankcase cover 3 If only remove unloading gear arm is not required to remove unloading gear drum assembly can be directly dr...

Page 98: ...ssembly See Mount of left hand crankcase cover 4 Mount the left hand crankcase cover See Mount of right crankcase cover Warning Thread retaining adhesive LOCTITE243 must be applied to the rotor retain...

Page 99: ...YG125 30A Maintenance Manual Frame and exhaust system 106 10 Frame and exhaust system https www motomanuals net...

Page 100: ...of component Trouble symptom of motorcycle Repair method Frame The frame is deformed or broken The frame is deformed or broken Running off tracking Calibrate or replace frame Main stand Deformation o...

Page 101: ...move the headlamp Pull off the left right turn lamp connecting wire from the headlamp bracket Remove the meter assembly total of 2 connecting bolts To mount the coverings headlamp and meter The instal...

Page 102: ...placement of turn lamp bulb Loosen the screws remove the lamp lampshade Lightly press bulb rotate in counter clockwise Install new bulb in opposite order as below Front and rear lamp bulb12V10W Tailli...

Page 103: ...in the reverse order of removal The muffler seal gasket at the engine s exhaust port shall be replaced with a new one While mounting apply sealants at the joining part of the exhaust pipe and the muf...

Page 104: ...YG125 30A Maintenance Manual Front wheel front overhang and steering stem 110 11 Front wheel front suspension device and steering stem https www motomanuals net...

Page 105: ...Front wheel spindle 50N m 60N m Steering handle set bolt 20 30N m Front fork vertical pipe cap nut 50 60N m Upper lower connection plate set bolt 8 12N m Brake disc fastening nut 20 30N m Troubleshoot...

Page 106: ...cable The clutch is slipping or not fully disconnected Replace control steel cable Rear brake pedal The free stroke is over small The clutch is not fully disconnected Readjust the free stoke The free...

Page 107: ...d Over worn or damaged Over soft at front shock cylinder Replace piston rod Piston ring is over worn or damaged Over soft at front shock cylinder Replace piston ring Oil sealing Cut edge is over Worn...

Page 108: ...exhaust front brake oil way oil pipe is broken oil leakage from oil pipe brake lose effect replace oil pipe front brake oil pipe is clogged oil pipe is clogged brake lose effect clean or replace oil...

Page 109: ...ne Remove the right combination switch Remove the right brake cylinder body Remove the clutch control line and disassemble the connection of the clutch switch leads and the main cable Remove the left...

Page 110: ...nnection board and then the bolt at direction of the tube up to the torque of 20 30N m 4 Do not mount the throttle cable in the opposite direction of the feeder on the right handle otherwise the handl...

Page 111: ...l spindle on the V holder and measure the deflection of the wheel spindle with a dial gauge if the reading is no less than 0 2mm replace the front wheel spindle Front wheel bearing inspection Place th...

Page 112: ...the front brake caliper apply the thread retaining adhesive LOCTITE 243 with the tightening torque being 20 30N m Check 1 Dismantle oil drain bolt and check bolt whether or not is loose 2 Drain off ab...

Page 113: ...ber spring and check it whether or not is distorted 490mm 9 Check length of return spring to check it whether or not is distored 29mm 10 Fill absorber oil per standard Oiling quantity of one front abs...

Page 114: ...adjust the adjusting nut and inspect it by turning it left and right and moving it up and down to ensure no vertical play and flexible rotating laterally Tighten the cap nut to the required torque of...

Page 115: ...holding and releasing the front brake handle until the brake strip and the brake disc are well engaged Front brake disc inspection Measure the thickness of the brake disc with an outside micrometer i...

Page 116: ...YG125 30A Maintenance Manual Front wheel front suspension device and steering stem 122 https www motomanuals net...

Page 117: ...YG125 30A Maintenance Manual Rear wheel and rear suspension device 123 12 Rear wheel and rear suspension device https www motomanuals net...

Page 118: ...ably stand the motorcycle from under the engine a jack or other supports Key torque values Real wheel spindle nut 60 90 N m Rear fork shaft nut 50 60N m Troubleshooting Rear wheel shimmy 1 Rim bent 2...

Page 119: ...mage form Trouble symptom of component Trouble symptom of motorcycle Repair method Sprocket and cam sprocket Gear is over wor Drive chain has abnormal sound drive chain is easy to fall out Replace spr...

Page 120: ...lines of the chain adjuster are consistent and then fasten the rear wheel spindle nut to the required tightening torque of 60 90N m Warning The rear wheel spindle must be firmly screwed up to the requ...

Page 121: ...olt 4 Take out the rear fork backwards To install the rear fork Installation is in the reverse order of removal While installing the rear fork shaft make sure that the end covers shall be aligned and...

Page 122: ...rder of removal While installing use the upper hole for the lower installation of the damper Notice Before removing the damper the tightening torque of the bolt connecting the frame is 30 40N m and th...

Page 123: ...al is convenient first following the principle of searching from easy to difficulty Both the parameter detection method and the parts replacement method are acceptable However if the parts replacement...

Page 124: ...ents include recharging charge storing and discharging YG125 30A power supply features large power supply capacity as high as more than 250W It comprises the following parts and components Magneto Var...

Page 125: ...broken circuit by millimeter 3 Open left cover to check magneto coil whether is burned or loose 4 Dismantle magneto bolt and replace magneto coil 5 Dismantle starting clutch and replace magnetic case...

Page 126: ...s terminal voltage is less then 12V The vehicle has been stored for too long and the accumulator has discharged automatically Charging circuit fails in the complete vehicle Accumulator fails to store...

Page 127: ...the relay start the engine to drive the idle gear and starter gear thus enabling the engine to enter its operating cycle for normal ignition fuel injection and combustion The system consists of the f...

Page 128: ...ged 4 Check rectifier whether is charged 5 Check fuse whether is burned 6 Check positive and negative pole of battery whether contact well 7 Check relay whether is damaged 8 Check magneto coil whether...

Page 129: ...e shift position switch Connect the line or replace clutch switch Connect the line or replace the left switch Connect the line or replace the left switch Replace the starting relay Repair or replace m...

Page 130: ...e to dodge by the flash of the turn lamp while driving at night it shall inform of its presence by the tail lamp s front rear position lamp and illuminate the number on the license plate while braking...

Page 131: ...YG125 30A Maintenance Manual Illumination signal system 137 Circuit schematic drawing https www motomanuals net...

Page 132: ...arged 5 Check fuse whether is burned 6 Take off headlamp switch socket to check whether there is current 7 Dismantle headlamp bolt to check lamp case whether is damaged 8 Take out headlamp bulb to che...

Page 133: ...on whether is rusted or lose contact Adjust velum of electrical horn to check it whether is damaged 18 Check neutral socket whether contact well 19 Signal lamp control systems Check flasher whether is...

Page 134: ...nation signal system 140 Major parts and components Head lamp Combined rear position lamp Front brake lamp switch Rear brake lamp switch Horn Right combination switch Left combination switch Fuel leve...

Page 135: ...of the main cable are open Connect the fuse or replace it Repair or replace the left switch Replace bulb Re plug Repair or replace main cable Brake lamp does not illuminate Corresponding fuse is not...

Page 136: ...vehicle information the YG125 30A displays include vehicle speed engine speed fuel indicator Neutral indicator turn indication high beam indication total subtotal mileage traveled and EFI Indicator Co...

Page 137: ...or 3 Meter reading and usage 1 Speedometer Indicate motorcycle speed Km h Do not exceed legal rate limiting to assure safe riding 2 Odometer Indicate riding distance Km 3 Turn indicator R right turn t...

Page 138: ...rt whether energize 2 Check fuse whether is burned 3 Dismantle headlamp holder to check holder whether there is current 4 Dismantle meter bolt to check it whether is loose or damaged 5 Dismantle meter...

Page 139: ...re Line poorly plugged or open circuit Meter failed ECU failed Re plug or repair Replace meter Replace ECU Fuel level indication failure No indication while there is fuel Having indication while there...

Page 140: ...ugh the engine and actuators on the vehicle ignition coil fuel injector Idle speed control valve and so on the fuel and fire are exactly controlled and corrected with closed loop For production confor...

Page 141: ...ement system 147 Major parts and components Intake air pressure sensor Throttle sensor Fuel Injector Idle speed control valve Cylinder Head Temperature Sensor Throttle body Electronic control unit ECU...

Page 142: ...YG125 30A Maintenance Manual Engine management system 148 Circuit schematic drawing https www motomanuals net...

Page 143: ...ctors 3 Make sure the temperature of the ECU is below 80 4 The fuel pressure is much high about 250kPa so please do not disassemble the fuel pipe arbitrariliy If have to pleae release the pressure at...

Page 144: ...erature Sensor Circuit Low Voltage KsDGDM_CoolantShortLow P0118 Coolant Oil Temperature Sensor Circuit High Voltage or Open KsDGDM_CoolantShortHigh Throttle Position Sensor TPS P0122 TPS Circuit Low V...

Page 145: ...s Setp 5 No Next 3 Remove the connector and use the multimeter to check whether the resistance between pin B and D is reasonable according to the temperature Yes Step 5 No Next 4 Remove the connector...

Page 146: ...imeter to check whether the resistance between pin A and C of the sensor is reasonable according to the temperature Yes Step 5 No Next 4 Use the multimeter to measure whether the voltage between A and...

Page 147: ...the throttle to 100 slowly check whether the data of throttle opening goes to between 90 100 Yes Step 5 No Next 4 Repeat Step 3 check whether the data jumps when open the throttle slowly Yes Change t...

Page 148: ...tage of the relay feeder ear is about 12V Yes Change the pump No Next 3 Check whether the feeder ear is short to ground or open Yes Harness issue No Help Malfcode P0351 Information Cylinder 1 Ignition...

Page 149: ...hange the ECU and repeat the test if the issue is gone then the root cause is the ECU Or change the old one back to check the root cause ITEM OPERATION RESULT NEXT STEP Engine cannot start Check wheth...

Page 150: ...whether the intake pipe leaks Yes Intake system maintenance No Next Whether there is carbon deposit at the throttle body and bypass channel Yes Clean the TB No Next Check whether the IACV works well Y...

Page 151: ...xt No Change the sprk plug Check whether the cylinder pressure is normal Yes Next No Check the engine Check whether the exhaust pipe is blocked or not No help Yes maintenance Backfire Pull out the spa...

Page 152: ...YG125 30A Maintenance Manual Electrical System Diagram 158 19 Electrical System Diagram https www motomanuals net...

Page 153: ...e copyright is owned by the company and shall not be copied or reproduced without permission Chongqing YINGANG technology group co LTD Address No 71 tongxing nan road beibei district chongqing China T...

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