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YG125-25 Maintenance Manual                                           Electrical starting control system 

Major parts and components

 

Combination meter

 

 

1. 

Outline drawing 

 

 

 

 

 

2.  Line color function corresponding table 

S/N 

COLOUR 

FUNCTION 

S/N 

COLOUR 

FUNCTION 

Black 

Power ) 

Green/ Red 

Neutral indicator 

green 

Power Supply(-) 

Black/ Yellow 

The rotational speed signal 

Brown 

Instrument lighting 

Yellow / white 

Fuel oil signal 

Blue 

Headlight high-beam indicator 

10 

Red 

Battery power supply

+

 

Light blue 

Right turn indicator 

11 

Green / Blue 

EFI indicator 

Orange 

Left turn indicator 

 

 

 

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

twinkle when turn to right(Green). 

 

L

left turn

twinkle when turn to left(Green). 

4) 

Headlight high-beam indicator 

light on when Far light is switched on. 

5) 

Neutral indicator   

It is lit up when in the neutral position. 

6) 

Tachometer 

It shows the speed(rpm) of the engine. 

7) 

Fuel gauge 

Display tank fuel oil 

8) 

Trip meter 

It shows the mileage of trip in kilometers. 

9) 

Trip meter knob 

Indicate distance from Zero, by rotating Zero Knob to the Direction of Arrow can return it to Zero. 

10)  EFI Indicator 

Indicating EFI system situation 

 

 

140 

 

Summary of Contents for YG125-25

Page 1: ...escribes various constituting parts of the motorcycle respectively Chapter 19 contains the electrical system diagram The standard maintenance procedures maintenance precautions and general maintenance...

Page 2: ...tem 76 84 9 Crankcase crankshaft and Shift mechanism 85 101 10 Frame and exhaust system 102 106 11 Front wheel front overhang and steering stem 107 118 12 Rear wheel and rear overhang 119 124 13 Gener...

Page 3: ...ion Bar Tool About Motorcycle Maintenance Maintenance Period Table Technical Data of Main Performance Symbol Descriptions Standard Torque Values Engine Number Position Photo of Complete Vehicle Frame...

Page 4: ...components 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...

Page 5: ...m breaking or bending Make 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...

Page 6: ...or sharp corners of the vehicle body 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...

Page 7: ...nce manual after understanding the explanations in the instruction manual 17 Do not drop or throw the parts and components 18 In case of rust on the terminals carry out connection operation after disp...

Page 8: ...urb weight 213kg Vehicle body Frame type Rake angle Front suspension device Rear suspension device Front Tire size Rear Tire size Front wheel pressure Rear wheel pressure Front brake Rear brake Fuel t...

Page 9: ...ype Sequence I N V Engine Mode Cylinder bore Stroke Cylinder displacement Compression ratio Max power Max torque Valve clearance cold Valve driving gear Air filter Cooling method Lubrication method En...

Page 10: ...Torque Values ENGINE Item Quantity Thread diameter mm Torque value N m Thread locker Cylinder head cover connecting bolt 13 8 8 12 Cylinder bolt 4 10 40 50 2 6 8 12 Valve adjusting screw nut 4 10 8 12...

Page 11: ...30 40 Upper connection plate set bolt 2 6 8 12 Rear sprocket nut 6 8 20 30 LOCTITE 243 Brake disc fastening nut 8 8 20 30 LOCTITE 243 Speed signal panel screw 4 8 20 30 LOCTITE 243 Front brake calipe...

Page 12: ...ric special tool for cross hexagon gun tip Valve adjusting socket for valve clearance adjustment Socket for mantling dismantling nuts and bolts Cutting plier Nipper plier expansion plier for mantling...

Page 13: ...imes Maintenance Items Period Odometer km Remark 2 1000 km 4 000 km 8 000 km 12 000 km Remarks Fuel system passage I I I Throttle operating system I I I I Throttle valve body I I I I Air filter elemen...

Page 14: ...nt lubrication or replacement C Cleaning R Replacement A Adjustment L Lubrication This item is subject to maintenance by persons from YINGANG TECNOLOGY Service Station If the user has special service...

Page 15: ...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 during operating inspecting and mainta...

Page 16: ...its quality 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...

Page 17: ...cle Among the positions shown in the above diagram besides applying dedicated lubricating oil for chain to the driving chain apply lithium base grease to all other positions All lubricating oils not s...

Page 18: ...l Lubrication system Engine Lubrication System Diagram Crankshaft oil through Spindle oil through Countershaft oil through Camshaft oil through Cylinder head oil through Cylinder oil through Oil filte...

Page 19: ...drain plug 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 refi...

Page 20: ...he oil drain plug and proceed with the remaining steps according to the method of Replacement of Lubricating Oil Cleaning and Replacement of Lubricating Oil Filter Remove the engine oil filter cover t...

Page 21: ...d illustration for oil pump installation Disassembly and assembly 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...

Page 22: ...replaced 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 t...

Page 23: ...the sense 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 geomet...

Page 24: ...ycle according to the contents hereof before using it Technical specifications Throttle bar free stroke 1 3mm Recommended spark plug D8RTC Spark plug gap 0 7 0 9mm Valve clearance cold IN 0 06 0 08mm...

Page 25: ...g sealing gasket is in good 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 motorcy...

Page 26: ...m is abnormal 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...

Page 27: ...ound Dah Dah it 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 det...

Page 28: ...right position but rock 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 flywhee...

Page 29: ...by an ECU 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...

Page 30: ...the retaining nut A and mount the protective rubber lagging Coarse adjustment If the fine adjustment is not satisfying separate the throttle control line with throttle valve body and unscrew the reta...

Page 31: ...e caliper after the brake fluid is pumped out firmly nip the handle or completely push down quickly screw the deflating valve bolt with the torque being 7 9 N m 6 Mount the brake cylinder cover with t...

Page 32: ...it Please change it 2 If it needs to be changed Please go to the designated special maintenance station And it is better to use the parts from our company Caution Please change the brake shoe in time...

Page 33: ...transmission system should adjust 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 scr...

Page 34: ...of the lower chain Driving chain tension 10 20mm If 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 ad...

Page 35: ...han 12V recharge 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 Whil...

Page 36: ...e the buckle strip 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 b...

Page 37: ...e 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 Install new bulb in opposite order as belo...

Page 38: ...bly 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 whether the whole suspension assembl...

Page 39: ...YG125 25 Maintenance Manual Fuel system 4 Fuel system Fuel tank Throttle valve body Air filter 39...

Page 40: ...osition of 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 openin...

Page 41: ...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 contamination Removal...

Page 42: ...Installation steps The installation procedures are the removal procedures in reverse order While installing the locating slot must be aligned with the locating lobe of throttle body Warning Do not fu...

Page 43: ...dust deposit 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...

Page 44: ...YG125 25 Maintenance Manual Removal and installation of engine 5 Removal and installation of engine 44...

Page 45: ...oil To maintain 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 r...

Page 46: ...nk 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 Remove the starti...

Page 47: ...he engine hanging plate Front suspension 16 To take out the rear fork shaft and move the rear fork backwards Remove the drive chain Remove the rear absorber and rear fork connecting bolt Unscrew the n...

Page 48: ...ion note that the wiring of cable shall be in strict accordance with the wiring diagram Remove the 4 engine bracket and the frame connecting bolt Remove the 2 front suspension bolt Remove the 2 rear s...

Page 49: ...YG125 25 Maintenance Manual Cylinder Head Cylinder and Piston 6 Cylinder head cylinder and piston Cylinder head cover Cylinder head Cylinder 49...

Page 50: ...compressed air While assembling 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...

Page 51: ...mm 0 013mm Connecting rod small 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 rin...

Page 52: ...piston ring 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 Pi...

Page 53: ...aution Do not drop the location 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 conf...

Page 54: ...ng pins 6 Remove 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 th...

Page 55: ...e 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 te...

Page 56: ...se To mount the cylinder head Installation is in the reverse order of removal Precautions for installation 1 Confirm the location pin clean all parts and components and check whether the cylinder head...

Page 57: ...oil shield lip while mounting The valve lock clamp must be mounted in place dropout of the valve lock clamp is dangerous No Procedure Quantity Remarks 1 cylinder block 1 2 Cylinder head gasket 1 Coat...

Page 58: ...the planeness of the cylinder s joining surface Maintenance limit 0 05mm Measure the valve guide aperture Maintenance limit 4 53mm Measure the valve stem diameter Maintenance limit IN 5 15mm EX 5 15mm...

Page 59: ...se order of removal Precautions for installation 1 Confirm the location pin clean all parts and components and check whether the cylinder oil through is unobstructed clean and free of leak 2 Replace a...

Page 60: ...head See Removal of cylinder head 4 Remove the cylinder See Removal of cylinder 5 Remove the piston pin retainer at one side and pull out the piston pin 6 Take out the piston Notice Do not drop the p...

Page 61: ...ring mount the corrugated ring first then mount the lip rings at both sides with the corrugated ring joint staggering with both lip rings by 90 and with the two lip rings staggering with each other b...

Page 62: ...eter Maintenance limit 20 05mm Measure the 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...

Page 63: ...YG125 25 Maintenance Manual Clutch and Right crankcase cover 7 Clutch and Right crankcase cover Clutch Right crankcase cove Engine 64...

Page 64: ...s and components 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...

Page 65: ...pressure 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 sli...

Page 66: ...e right crankcase 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 loca...

Page 67: ...ection of 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 As...

Page 68: ...case 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 lever...

Page 69: ...her 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 retaining nut M18 Note to assemble wi...

Page 70: ...over 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 on the clutch retaini...

Page 71: ...utch friction plate 5 10 clutch driven plate 4 Assemble with the sub stage side facing inwards 11 Clutch platen 1 12 Clutch spring 4 13 Clutch plate 1 14 Bolt m6 25 4 Disassemble and assemble of clutc...

Page 72: ...the same way for screwing up bolt No Procedure Quantity Remarks Removing order Installation is in the reverse order of removal 1 clutch bush 1 Tightening torque 12N m 2 clutch assembly 1 3 Nut M14 1...

Page 73: ...ance limit 2 8mm 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 Me...

Page 74: ...YG125 25 Maintenance Manual Magneto and starting system 8 Magneto and starting system Engine Double linked Gear Rotor assembly Left front cover Idle gear Disk gear Double linked gear cover 76...

Page 75: ...rts coat the 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 specificatio...

Page 76: ...r cover and 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...

Page 77: ...hile assembling 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 Quantit...

Page 78: ...e linked 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...

Page 79: ...10 14N m No Procedure Quantity Remarks Removing order Installation is in the reverse order of removal 1 Screw M8 16 6 Use thread retaining adhesive LOCTITE 648 while assembling with the tightening tor...

Page 80: ...fasten the rotor and screw up the nut M12 to the torque of 45N m 4 To install the double linked gear The Washer and the double linked gear is assembled into the left crankcase 5 To install the left fr...

Page 81: ...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 Check 1 Check the spline gear of...

Page 82: ...Maintenance Manual Crankcase crankshaft and Shift mechanism 9 Crankcase crankshaft and Shift mechanism Right hand crankcase body Crankshaft Gearshift drum Counter shaft Main shaft Left hand crankcase...

Page 83: ...e removed 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...

Page 84: ...hift fork 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 for...

Page 85: ...anks haft and balance shaft Notice 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 crank...

Page 86: ...aft cylinder head cylinder piston 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...

Page 87: ...n is in the reverse order of removal 1 Right hand crankcase 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...

Page 88: ...moved Notice Do not dent the sealing surface and assemble the driving shaft bearing with the side with oil seal facing inwards No Procedure Quantity Remarks Removing order Installation is in the rever...

Page 89: ...le the driven shaft bearing with the side with oil seal facing inwards No Procedure Quantity Remarks Removing order Installation is in the reverse order of removal 1 Right hand crankcase 1 2 Balance s...

Page 90: ...perating table and use a high power electric drier to heat the right crankcase body crankshaft bearing until the temperature at the inner circle of the bearing reaches 106 and then assemble the cranks...

Page 91: ...mechanism Removal and installation of crankshaft and balance shaft No Procedure Quantity Remarks Removing order Installation is in the reverse order of removal 1 Left hand crankcase 1 2 Crankshaft 1 3...

Page 92: ...emarks Sequence of disassembling 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 Appl...

Page 93: ...sure the connecting rod small end bore diameter Maintenance limit 20 063mm 2 Measure the crankshaft radial run out Maintenance limit 0 10mm 3 Measure the connecting rod big end radial clearance Mainte...

Page 94: ...nce shaft on the assembly operating table and the driving driven 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...

Page 95: ...sassembling 1 Shift shaft 1 Apply engine oil while assembling 2 Pad 6 14 1 1 3 Bolt M6 28 2 4 Shift show 1 5 Shift show trigger 1 6 Shift fork 1 Apply engine oil while assembling 7 Shift fork right 1...

Page 96: ...t 5 80mm Shift mechanism To remove the shift mechanism 1 Removal of left hand crankcase cover See Removal of left hand crankcase cover 2 Remove the unloaded rotor assembly left crankcase assembly See...

Page 97: ...ombination Use oil seal guide to protect oil seal 3 Mount the rotor assembly See Mount of left hand crankcase cover 4 Mount the left hand crankcase cover See Mount of right crankcase cover Warning Thr...

Page 98: ...YG125 25 Maintenance Manual Frame and exhaust system 10 Frame and exhaust system 102...

Page 99: ...symptom 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 Defor...

Page 100: ...ove 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 install...

Page 101: ...bulb Replacement 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 bulb12V10...

Page 102: ...lation is 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 an...

Page 103: ...YG125 25 Maintenance Manual Front wheel front overhang and steering stem 11 Front wheel front suspension device and steering stem 107...

Page 104: ...round Key torque values 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 n...

Page 105: ...ng or is not fully disconnected Clean lubricate or replace control steel cable The steel cable The clutch is slipping or not fully disconnected Replace control steel cable Rear brake pedal The free st...

Page 106: ...ont 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 cyl...

Page 107: ...lace main pump piston Front brake caliper air entry into oil pipe brake lose effect exhaust front brake oil way oil pipe is broken oil leakage from oil pipe brake lose effect replace oil pipe front br...

Page 108: ...l line 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 l...

Page 109: ...t at the connection 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 otherwis...

Page 110: ...he front wheel 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 inspec...

Page 111: ...stalling 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 Dra...

Page 112: ...rn 8 Measure free length of absorber 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...

Page 113: ...ng stem 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 to...

Page 114: ...e it after 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 mi...

Page 115: ...YG125 25 Maintenance Manual Rear wheel and rear suspension device 12 Rear wheel and rear suspension device 119...

Page 116: ...mper reliably 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 Ri...

Page 117: ...ption Damage 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 Rep...

Page 118: ...right scale 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 u...

Page 119: ...end covers shall be aligned and that the tightening torque of the rear fork shaft retaining nut is 50 60N m Warning The rear fork retaining nut must be firmly screwed up to the required torque of 50...

Page 120: ...htening torque of the bolt connecting the frame is 30 40N m and the tightening torque of the bolt connecting the rear fork is 30 40N m Rear Brake Pulling the front rear brake checking the wear and tea...

Page 121: ...the removal 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 r...

Page 122: ...main contents include recharging charge storing and discharging YG125 25 power supply features large power supply capacity as high as more than 250W It comprises the following parts and components Mag...

Page 123: ...ircuit or 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 magn...

Page 124: ...umulator 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...

Page 125: ...power on 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...

Page 126: ...semble and maintain 1 Turn on ignition switch and flameout switch to check electrical start whether energize 2 Check plate electrode whether is damaged 3 Check charging coil of magneto whether is char...

Page 127: ...ether is damaged 8 Check magneto coil whether contact well 9 Check electrical starting switch whether contact well 10 Turn on electrical starting button to check whether is rusted or energize 11 Turn...

Page 128: ...h Connect the line or replace the left switch Connect the line or replace the left switch Replace the starting relay Repair or replace main cable Starting motor doesn t rotate there is the sound of re...

Page 129: ...and people 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 whil...

Page 130: ...YG125 25 Maintenance Manual Illumination signal system Circuit schematic drawing 134...

Page 131: ...ether is charged 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...

Page 132: ...horn button 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 w...

Page 133: ...Manual Illumination signal system 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...

Page 134: ...ed lines 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...

Page 135: ...complete vehicle information the YG125 25 displays include vehicle speed engine speed fuel indicator Neutral indicator turn indication high beam indication total subtotal mileage traveled and EFI Indi...

Page 136: ...indicator 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 righ...

Page 137: ...rical start 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 Disman...

Page 138: ...on failure 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 whi...

Page 139: ...dled Through 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 producti...

Page 140: ...f the intake pipe 3 Ageing level of the high voltage cable 4 Whether the ground connection is strong enough 5 All the connectors connected well Note if any item above exists please do the fix it at fi...

Page 141: ...Check the ignition system Check whether the cylinder pressure is normal Yes Engine is good No Check the engine Start Difficult Check wether the fuel pump pressure is about 250kPa at idle Yes Next No...

Page 142: ...her the IACV works well Yes Next No Change IACV Remove the engine temperature sensor and check whether the engine works well Yes Help No Change the sensor Acceleration gets worse Check whether the air...

Page 143: ...r the injeoctor is blocked Yes Clean or change the injector No Next Check whether the oxygen sensor works well Yes Help No Change the sensor Miss fire Pull out the spark plug check whether the sparkov...

Page 144: ...YG125 25 Maintenance Manual Electrical System Diagram 19 Electrical System Diagram 148...

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