TGB BF8 Service Manual Download

Page: 89 / 98

Watch:

The battery voltage must satisfy

requirement in checking starter voltage

Note:

(1) If there is voltage, then the relay is

normal.

(2) If there is no voltage, then check the

continuity of brake switch and cable.

Summary of Contents for BF8

Page 1: ...oor Acseleration and Horse Power 10 11 12 14 16 18 19 22 23 24 25 2 INSPECTION AND ADJUSTMENT 2 1 REGULAR MAINTENANCE SCHEDULE 2 2 INSPECTION AND CHANGE OF ENGINE OIL 2 3 FINAL GEAR OIL 2 4 BRAKE SYSTEM 2 5 TIRE AND TIRE PRESSURE 2 6 AIR CLEANER 2 7 BATTERY 2 8 SPARK PLUG 2 9 FUEL FILTER 2 10 CARBURETOR IDLE SPEED 2 11 THROTTLE VALVE 2 12 VALVE 2 13 HEADLIGHT AXLE 2 14 V BELT 2 15 CYLINDER PRESSUR...

Page 2: ...OUBLESHOOTING OF CHASSIS 4 3 FRONT WHEEL 4 4 REAR WHEEL 4 5 REAR SHOCK ABSORBER 70 72 76 78 80 5 ELECTRICAL SYSTEM 5 1 OPERATING CAUTIONS TROUBLESHOOTING 5 2 BATTERY 5 3 SHORT CIRCUIT TEST 5 4 RECTIFIER 5 5 STARTER RELAY 5 6 STARTER MOTOR 5 7 A C GENERATOR 5 8 RESISTOR 5 9 CDI UNIT APPENDIX CIRCUIT DIAGRAM FOR BR8 81 86 87 87 88 90 92 94 95 98 ...

Page 3: ...R NO SINGLE PRIMA 1 0 90 2 40 BORE STORKE mm 52 4 57 8 TRANSMISSION REDUCTION RATIO SECOND 1 9 45 14 43 13 40 DISPLACEMENT c c 124 HEAD LAMP H L 12V 35W 35W 1 STARTER ELECTRIC KICK REAR LAMP 12V 5W 1 BRAKE LAMP 12V 21W 1 COOLING FORCED AIR COOLING LAMP TURN LAMP 12V 10W 4 LUBRICATION PUMP SPLASH 130 60 13 130 60 13 INTAKE VALVE GAP mm 0 08 0 10 or120 70 12 130 70 12 EXHAUST VALVE GAP mm 0 08 0 10 ...

Page 4: ...1 0 90 2 40 BORE STORKE mm 52 4 57 8 TRANSMISSION REDUCTION RATIO SECOND 1 9 45 14 43 13 40 DISPLACEMENT c c 124 HEAD LAMP H L 12V 35W 35W 1 STARTER ELECTRIC KICK REAR LAMP 12V 5W 1 BRAKE LAMP 12V 21W 1 COOLING FORCED AIR COOLING LAMP TURN LAMP 12V 10W 4 LUBRICATION PUMP SPLASH 130 60 13 130 60 13 INTAKE VALVE GAP mm 0 08 0 10 or120 70 12 130 70 12 EXAUST VALVE GAP mm 0 08 0 10 FRONT REAR or120 70...

Page 5: ... 0 90 2 40 BORE STORKE mm 57 4 58 4 TRANSMISSION REDUCTION RATIO SECOND 1 7 8 15 42 14 39 DISPLACEMENT c c 151 HEAD LAMP H L 12V 35W 35W 1 STARTER ELECTRIC KICK REAR LAMP 12V 5W 1 BRAKE LAMP 12V 21W 1 COOLING FORCED AIR COOLING LAMP TURN LAMP 12V 10W 4 LUBRICATION PUMP SPLASH 130 60 13 130 60 13 INTAKE VALVE GAP mm 0 08 0 10 or120 70 12 130 70 12 EXAUST VALVE GAP mm 0 08 0 10 FRONT REAR or120 70 1...

Page 6: ...0 90 2 40 BORE STORKE mm 57 4 58 4 TRANSMISSION REDUCTION RATIO SECOND 1 7 8 15 42 14 39 DISPLACEMENT c c 151 HEAD LAMP H L 12V 35W 35W 1 STARTER ELECTRIC KICK REAR LAMP 12V 5W 1 BRAKE LAMP 12V 21W 1 COOLING FORCED AIR COOLING LAMP TURN LAMP 12V 10W 4 LUBRICATION PUMP SPLASH 130 60 13 130 60 13 INTAKE VALVE GAP mm 0 08 0 10 or120 70 12 130 70 12 EXAUST VALVE GAP mm 0 08 0 10 FRONT REAR or120 70 12...

Page 7: ...INGLE PRIMA 1 0 77 1 2 19 BORE STORKE mm 52 4 57 8 TRANSMISSION REDUCTION RATIO SECOND 1 8 61 15 42 13 40 DISPLACEMENT c c 124 HEAD LAMP H L 12V 35W 35W 1 or 18W 18W 2 STARTER ELECTRIC KICK REAR LAMP 12V 5W 1 BRAKE LAMP 12V 21W 1 COOLING FORCED AIR COOLINE LAMP TURN LAMP 12V 10W 4 LUBRICATION PUMP SPLASH INTAKE VALVE GAP mm 0 08 0 10 EXAUST VALVE GAP mm 0 08 0 10 FRONT REAR 120 90 10 110 90 10 TOP...

Page 8: ...LE PRIMA 1 0 90 2 40 BORE STORKE mm 52 4 57 8 TRANSMISSION REDUCTION RATIO SECOND 1 9 45 14 43 13 40 DISPLACEMENT c c 124 HEAD LAMP H L 12V 35W 35W 1 STARTER ELECTRIC KICK REAR LAMP 12V 5W 1 BRAKE LAMP 12V 21W 1 COOLING FORCED AIR COOLING LAMP TURN LAMP 12V 10W 4 LUBRICATION PUMP SPLASH 80 80 14 110 80 14 INTAKE VALVE GAP mm 0 08 0 10 or EXAUST VALVE GAP mm 0 08 0 10 FRONT REAR 110 80 14 110 80 14...

Page 9: ...LE PRIMA 1 0 90 2 40 BORE STORKE mm 57 4 58 4 TRANSMISSION REDUCTION RATIO SECOND 1 7 8 15 42 14 39 DISPLACEMENT c c 151 HEAD LAMP H L 12V 35W 35W 1 STARTER ELECTRIC KICK REAR LAMP 12V 5W 1 BRAKE LAMP 12V 21W 1 COOLING FORCED AIR COOLING LAMP TURN LAMP 12V 10W 4 LUBRICATION PUMP SPLASH 80 80 14 110 80 14 INTAKE VALVE GAP mm 0 08 0 10 or EXAUST VALVE GAP mm 0 08 0 10 FRONT REAR 110 80 14 110 80 14 ...

Page 10: ...e major components Arrange the parts in order during disassembly Make marks if necessary to avoid mistakes in re assembly 6 Loosing the parts should start from small to big from outside to inside and in alternative parts Assembly is in reverse order of disassembly procedures 7 The oil seals should be replaced with new ones after disassembly The contact surface should be cleaned up Check if the con...

Page 11: ...ct happens please wash with massive clean water and contact with doctor 2 The released H2 from battery is explosive Please keep good ventilation during charging battery and forbid any fire Watch Brake Fluid The brake fluid can damage the painting on plastic Please cover the plastic parts with towel or cloth during maintenance of brake disk If the brake fluid is split on plastic component please re...

Page 12: ...y Four Legs Sleeve 440604 Used for removing starter clutch gear lock nut Flywheel Remover 440602 Used for removing flywheel Starter Spring Assembly Tool 440605 Used for starter spring assembly Gear Remover 440603 Used for removing starter driven gear Crank Shaft Right Hand Crank Case 440606 To draw the crank shaft into the right hand crank case ...

Page 13: ...ain Bush Remover 440610 For removing the crankcase suspension bush Socket of Valve Adjusting Bolt 440608 Adjust the clearance of valve stem and rock arm Fixing Nut Socket 440611 Used for removing steering shaft nut Valve Cotter Tool 440609 For assembling valve cotter ...

Page 14: ... and Nut 90 12 mm Bolt and Nut 550 Torque Values of Chassis Components No Tightening Location Specification Torque kg cm 1 Front Wheel Axle Self lock Nut M12 500 600 2 Brake Disk Hex Bolt M5 180 280 3 Brake Clipper Tightening Bolt M8x35 210 250 4 Speed Meter Cable Nut X 60 5 Front Fork Bearing Tightening Nut M25x1 0 600 650 6 Rear Wheel Axle Self lock Nut M16x10 600 900 7 Rear Brake Connecting Rod...

Page 15: ...ight Crankcase Lower Tightening Screw M8x38 300 400 1 Spark Plug M10 100 120 1 Valve Gap Adjust Lock Bolt M5 50 90 2 Fuel Filter Nut Cap M30 150 200 1 Cooler Fan Lock CR M6x18 500 800 4 Wire Assembly Lock Screw M6x20 800 1000 2 Start Clutch Gear ightening Nut M22 R T 800 1000 1 Driven Belt Pully Assembly M12 400 600 1 Gearbox Cover Tightening Bolt M6x28 100 1200 3 M6x35 3 Gearbox Oil Fill Cover Sc...

Page 16: ...Area Lubrication Type Inner Side of Acceleration Lever Grease Steering Bearing Speed Meter Gear Front Wheel Axle Bearing Front Wheel Axle Main and Side Stand Axles Rear Wheel Bearing Seat Cover Lock Speed Meter Cable Throttle Wire Rear Brake Cable Brake Assembly Brake Fluid ...

Page 17: ...ea Cam Shaft and Chain Cylinder Frictional Area Oil Pump Chain Gears Contact Surface Bearing Operation Area O Rings Seal Lip Area Satisfy SAE 10W 40 and API SE SG Engine Oil Starter Frictional Surface Starting Cam Gear Spring Operation Frictional Area High Temperature Durable Grease Generator Connector Gearbox Ventilation Tube Adhesives ...

Page 18: ...18 1 7 PARTS NAME AND WIRING DIAGRAM Parts Name BR8 Representative Figure ...

Page 19: ... Check if the crank shaft works Does not work works Check if the starting motor works Check RPM Poor too slow Fair Check battery charging and contact of pins Loosen the carburetor leakage screw to check for inlet of fuel Fair Poor Check for existence of water or other impurities in the carburetor buoyant Check for fuel in the fuel tank Fair Poor Check for fuel spill in the carburetor Clean the car...

Page 20: ...etor need to be regulated Poor Fair Test the compression Clean or replace the slow nozzle or correct replace with new threshold Check choke of the carburetor for troubles Readjustment Poor Fair Adjust or replace new choke parts Check if the slop nozzle of the carburetor is obstructed or the threshold fails Poor Fair Check air filter grill for obstruction Check cylinder washer for leakage check cyl...

Page 21: ...oose adjustment screws in the carburetor z Carburetor choke z Obstructed carburetor slow nozzle z Ailing carburetor threshold z Obstructed air filter grill z Leakage in cylinder washer z Seriously damaged cylinder piston piston z Dead battery z Poor contact of battery pin and conductors z Starting switch with poor or failure z Starting relay with broken wire or short circuit z Loose contact and wi...

Page 22: ...r distributor coils z Poor PICK Ups z Poor main switches z Wiring relay Poor or abnormal C D I or plugs replacement of C D I and mount properly the plug Check high voltage coils main switches PICK UP distributor coil for normality High sparks Check for loose C D I plugs terminal conduction and resistance values Replacement of poor spark plug Abnormal Normal Poor high voltage coils main switches PI...

Page 23: ... voltage wiring z Poor main switch z Main wiring broken or in short circuit z Ignition coil broken or in short circuit z Poor adapter contact Load properly the C D I adapter Check C D I terminals passage and testing of resistance Weak sparks Replacement of poor spark plugs Check for loose C D I contacts Loose Normal a Poor PICK UP b Poor main switch c Poor contact of adapter d Broken main wiring o...

Page 24: ...agement of cylinder head washer z Severe wear of cylinder piston piston ring Replacement of the filter grill Is the carburetor buoyant level normal Fair adjustment Is the air filter grill obstructed Poor Fair Adjustment or replacement of the buoyant needle valve Fair Poor Check if the choke valve fails valve does not open Check of for air between the carburetor and the air inlet Fair Poor Correcti...

Page 25: ... Dirty or obstructed carburetor injection nozzle z Poor carburetor buoyant needle valve z Dirty fuel filter z Obstructed fuel circuitry z Poor engagement of cylinder washer z Serious damage of cylinder piston piston ring Cleaning adjustment of replacement of new spark plugs Check for normal ignition timing Check for burn of spark plugs and the gap Replacement of the filter grill Intense sparks Poo...

Page 26: ...ustment or replacement when necessary Check for normal fluid level in the buoyant Cleaning or replacement Fair Poor Check the compression Check of needle valve and buoyant Fair Poor low level Check fuel pipe and carburetor for obstruction Adjustment or replacement Fair Poor Cleaning or replacement ...

Page 27: ...tery I I I Spark Plug C C C C Fuel Filter R R Carburetor I I C Valve A A A A V Belt I Bolts and Nuts T Note 1 If ridden on dusty roads or raining days please shorten the inspection and replacement schedule for air filter 2 If ridden under heavy load frequent long distance travel please shorten the replacement schedule for engine oil 3 Please clean the spark plug regularly and replace the spark plu...

Page 28: ...n the maintenance schedule for oil change Please put oil tray under the left crankcase and remove the oil drain plug Re install the drain plug when the engine oil is drained Clean up the oil filter Inspection 1 If O ring is damaged please replace with new one 2 If there is any deposit please use clean up before re assembly Note 1 Torque of oil strainer screen 150 200 kg cm 2 Lubrication Type SAE 1...

Page 29: ...spection Check if the oil drain plug washer is damaged Please replace with new one if it is damaged Drain gear oil Assembly Assembly drain plug Refill gearbox oil Reinstall oil refill plug Note 1 Torque on drain plug 90 150 kg cm 2 Oil type SAE 90 3 Oil capacity BH8 Gearbox disassembled 110 c c Regular Maintenance 90 c c BR8 BF8 BR9 BF9 Gearbox disassembled 120 c c Regular Maintenance 100 c c 4 Pl...

Page 30: ...h Please place main stand to park the motorcycle for inspection Disassembly 2 tightening bolts on fuel cover Fuel trap Diaphragm Refill brake fluid to level between MIN and MAX Assembly Assembly is in reverse order of disassembly procedures Warning 1 Please refill the same type of brake fluid Different fluid type may create toxic chemical ingredient and can damage the brake 2 Please do not let wat...

Page 31: ... not release the brake lever 4 Unplug the air release plug and still hold the brake lever 5 Tighten the air release bolt then release the brake lever 6 Repeat procedure 1 to 5 and release air bubble completely Note Torque of air release bolt 60 kg cm E Front Brake Disk Inspection If there is scratches damage or wear please replace with new one Note The minimum disk thickness 3 0 mm ...

Page 32: ... 5 mm B If eccentricity is not within the limit please check tire roundness If wheel rim roundness is not within the limit then change the brake disk F Rear Brake Adjustment Note The free play of rear brake lever 10 20 mm Adjustment Adjust the adjustment nut ...

Page 33: ...ust pipe and right crankcase Tightening nut on rear wheel axle Washer Rear wheel Inspection check rear wheel rim inner diameter If it is badly worn please replace with new one Note 1 Please use vacuum to clean wheel rim and lining Try to reduce the contamination of asbestos fiber which may affect the human breath system or lead to cancer 2 Use the Vernier calipers to measure the diameter of wheel ...

Page 34: ... and center If badly worn please replace with new one brake shoe and brake shoe spring Note 1 Useable thickness is 2 0 mm 2 If less than useable thickness please replace with new parts Assembly Assembly is in reverse order of disassembly procedures Note 1 Torque of rear wheel bearing bolt 600 900 kg cm 2 Torque of 2 bolts on exhaust pipe connector 100 120 kg cm 3 Torque of 2 bolts on exhaust pipe ...

Page 35: ...re pressure Front tire 175kPa 1 78 2 25 38 PSI Rear tire 210kPa 2 14 2 30 45 PSI Warning Don t over load the motorcycle The tire may explode with over load and it is d 2 6 AIR FILTER Disassembly Air filter side cover tightening bolt Air filter side co ver Filter tightening bolt Filter Inspection Check if filter is filthy or broken If filthy or broken please replace with new one Watch 1 If ridden o...

Page 36: ...t the battery negative cable and then the positive cable Warning Please do not touch tools with frame buring disconnecting positive cable It can cause short circuit then it may spark and damage battery Inspection This motorcycle use wet type battery Please fill with distillation water or lead battery fluid when the electrolysis fluid is lower than minimum Assembly Assembly is in reverse order of d...

Page 37: ...teel brush to remove carbon deposits and adjust spark plug gap Replace burned or cracked spark plug with new one Note Spark plug specification CR7HAS NGK Spark plug gap 0 6 0 7 mm Warning First install the spark plug with hand and then tighten it with spark plug wrench Please do not over twist the spark plug Note Torque of spark plug 100 120 kg cm 2 9 FUEL FILTER Inspection Check if it is hardened...

Page 38: ...e screw counter clockwise 3 Engine idle speed range 1800 100 rpm 2 11 THROTTLE VALVE Inspection Check if the throttle valve operation is smooth Note 1 Throttle lever free play 2 6 cm 2 Micro adjustment is performed at throttle lever Macro adjustment is performed at carburetor throttle valve cable A Throttle Lever Gap Adjust Procedures Open dust boot Loose lock bolt Adjust by rotating adjust nut No...

Page 39: ...djustment 2 12 VALVE Disassembly Cylinder head bolt Cylinder head Note 1 Inspect and adjust are performed at engine temperature lower than 35o C 2 Rotate the cooler fan such that the mark on cam shaft gear match the top dead center position and the T mark on flywheel match the mark on crankcase Then perform check and adjustment Adjustment Use valve adjust wrench to loose tightening bolt and rotate...

Page 40: ...ght axle 2 Rotate the nut counter clockwise for lower light axle 2 14 V BELT Watch Please place main stand to park the motorcycle for inspection Disassembly Loose the cooler tube tightening ring Kicker starter arm tightening bolt Kicker starter arm 8 clutch side cover tightening bolts Clutch side plate Gasket ...

Page 41: ...ngth Wear limit 18 0 mm or 8000km 2 Belt specification BH8 BANDO VS BELT 743 20 30 BR8 BF8 BR9 BF9 BANDO VS BELT 846 20 30 Assembly Assembly is in reverse order of disassembly procedures Warning Please do not apply any grease on pulley and V belt which can cause belt slip Note 1 Diver plate screw is left threaded 2 Torque of driver plate nut 800 1000 kg cm 3 Torque of clutch side nut 50 60 kg cm 4...

Page 42: ... motor by pressing the start button and measure cylinder pressure Note 1 Cylinder pressure BH8 BR8 BF8 125c c engine 12 8 570 kg cm2 rpm BR9 BF9 151c c engine 11 7 700 kg cm2 rpm 2 Reasons of too high cylinder pressure A Carbon deposits at combustion chamber B Carbon deposits on piston top surface 3 Reasons of too low cylinder pressure A Valve gap too small B Worn valve seat or seat is not complet...

Page 43: ...2 500 57 400 57 410 57 500 Roundness 0 05 0 05 Cylinder Cylinder degree 0 05 0 05 Piston outer diameter 52 370 52 390 52 300 57 375 57 395 57 300 Inner diameter of piston pin 15 002 15 008 15 040 15 002 15 008 15 040 Gap between cylinder and piston 0 010 0 040 0 100 0 005 0 035 0 100 Top ring 0 015 0 055 0 090 0 015 0 050 0 090 Gap between Piston and piston ring Second ring 0 015 0 055 0 090 0 015...

Page 44: ...nd cylinders due to friction Wear of connecting rod small end holes and piston rings Knocking pistons Serious damage of cylinders pistons and piston rings by friction wear Wear of piston pins and piston pin holes Low compression rate Wear or break of piston rings Wear or damage of cylinder walls and pistons Too narrow gap or no gap at all of valve Gap between valve and its seat Valve burnt Valve u...

Page 45: ...a new filter if it is badly dirty or broken 3 4 2 Spark Plug Unscrew the spark plug with specified tool Examine the spark plug does any dirty deposit carbon or burn out Clean the spark plug if has dirty or deposit carbon with steel brush Measure the clearance of the spark gap The gap standard is 0 6 0 7 mm 3 4 3 Cylinder head and Timing Remove the fan cover cooling fan and shroud set Release the c...

Page 46: ...e combustion chamber and shown no sign of cracks or damage Use a calibrated rule inspect the cylinder head lower surface is perfect flatness Use a thickness gauge inspect that the surface wear does not exceed 0 05mm Measure the free length of the valve springs The limit of inner spring is 31 2mm The limit of outer spring is 34 1mm Examine the valves should not be damaged cracked burnt or bended Cl...

Page 47: ...ar limit is 1 8mm maximum Lubricate the valve stems and suit them to the guides Fit the springs the upper cups and the lock cones Fit the valves with special tool carefully The springs may come off it is dangerous Gently tap the valve stems with a plastic nammer to make the cones in their seats Be carefully when doing this work Insert the two rocker arms shaft Fit a new cylinder head gasket and ke...

Page 48: ...ning torque is 200 kg cm Install the chain guide Loose the lock by turning the nut with counter clock direction Adjusting the valves Should align with rotate the crankshaft by hand until the circle hole marks on camshaft gear wheel and the other two mark line cylinder head then adjust the plays of the valves with special tool and with the aide of a thickness gauge measure the gap between the rocke...

Page 49: ...r inside surfaces show no signs of seizure or anomalous wear then measure the inside diameter of the cylinder with a bore meter Note BH8 BR8 BF8 125c c engine Wear limit Ф52 5mm BR9 BF9 151c c engine Wear limit Ф57 5mm Take measurements on three planes along the cylinder axis for each plane take a measurement on the circumference Take off the piston rings carefully Inspect the piston surface anoma...

Page 50: ...of top ring is 0 09mm The max clearance of 2nd ring is 0 09mm too Measure the diameter of the piston pin hole Wear limit is Ф15 04 mm Measure the piston pin outside diameter Wear limit is Ф14 96 mm Measure the inside diameter of the piston rod small end Wear limit is Ф15 06mm ...

Page 51: ...rings during the fitting and position them as shown in the figure Once fitted the rings must rotate freely in their grooves The 2nd ring is engraved 2R mark The 1st ring is engraved R mark The mark should face upwards while installing Assemble the piston the IN reference mark is at the inlet valve side Insert the piston pin and assembly rings Assemble the circlip carefully Fit the cylinder gasket ...

Page 52: ...n and chain guider Remove the oil divider and then remove the driving sprocket Remove the coupling bolts gasket and pin Take out the crankshaft from crankcase Check the side play of the piston rod big end with a thinness gauge Wear limit is 0 5mm ...

Page 53: ...bearings make sure that they rotate freely and have no play in their respective housings Fit the crankshaft and smear the coupling surfaces with Loctite fixing glue Fasten the flywheel side crankcase half to the transmission side crankcase half Fit the crankcase halves coupling screws Tightening torques 90 kg cm ...

Page 54: ...there is excessive play due to wear the throttle must be replaced Using the new gaskets when reassembling the carburetor Inspect if the pressure piston is worn or presents notches Inspect the vacuum membrane carefully Damaged or cut are not allowed 3 5 2 How to take off the carburetor Remove the fuel feed pipes Remove the automatic by choke connector Loosen the throttle control cable adjusting nut...

Page 55: ...of automatic choke must keep well Notches signs of wear scratches or other damage are not allowed 3 5 4 Membrane chamber Loosen the drain screw and let the fuel flow out from the float chamber Remove the two screws of the pressure chamber ...

Page 56: ...ect the pressure piston and membrane Notches scratches or other damage are not allowed Fit the needle the spring and the needle holder in the pressure piston and fix the needle holder Fit the pressure piston in the carburetor body Fit the compression spring Fit the pressure chamber cover and fasten it with two screws ...

Page 57: ...ts Unscrew the four float chamber screws Remove the float pivot the float and the needle Inspect the needle valve and its seat Notches or deep scratches are not allowed Remove the main jet choke jet and idling jet Inspect these jets ...

Page 58: ...m Replace the float if the level is not as indicated Fit the float chamber 3 5 6 Throttle Valve Loosen the fastening screws and remove the throttle valve Check that the valve rim shows no deep scratches Fix the throttle valve again with Anti loosen glue and new screws Note Before tightening the two screws of throttle valve carry out the following ti a Loosen the slow running adjuster completely so...

Page 59: ...e the outlet bolt and the oil lever gauge After draining the oil clean the oil lever gauge check the O ring seal and fit the oil lever gauge and outlet bolt again Tightening torque 150 kg cm Supply the engine with recommended oil through the oil filter Screw the filler plug Lubrication Type SAE 10W 40 Engine oil capacity BH8 BR8 BF8 125c c Engine disassembled 900c c Chang oil 750c c BR9 BF9 151c c...

Page 60: ...y diagonal step and then remove the clutch cover Take off the knock pins and remove the gasket 3 7 2 Driving pulley Use the special tool to lock the fixed drive face and loosen the central nut with wrench Remove the belt from the spacer and remove the drive pulley Note Press the movable drive plate and drive pulley face while removing the drive pulley face Assy in order to avoid the roller to stan...

Page 61: ...using with a compass spanner to hock the housing bell and loosen the nut with wrench Remove the driven pulley comp and belt 3 7 4 Checks Drive belt Be sure that the drive belt should not be cracked or damaged Measure the belt length Wear limit 18 0mm or 8000km ...

Page 62: ... should not to be damaged or worn BH8 Wear limit Ø18 0mm minimum BR8 BF8 BR9 BF9 Wear limit Ø17 4mm minimum Roller Bush Inspection that the internal bushing of drive bush should show no signs of anomalous wear and with bore meter to measure its inside diameter BH8 Wear limit Ø25 0mm maximum BR8 BF8 BR9 BF9 Wear limit Ø24 06mm maximum Note Take care to replace the rollers in their original position...

Page 63: ...asure the outside diameter of the spacer BH8 Wear limit Ø26 0mm minimum BR8 BF8 BR9 BF9 Wear limit Ø23 94mm minimum 3 7 5 Guide shoes Inspect the guide blocks should not be worn and then inlay them into the movable drive plate Assemble the movable drive plate cover ...

Page 64: ...riven pulley Remove the central nut with compass spanner to lock the driven pulley Warning Press tightly the driven pulley while unscrewing the nut so that the spring will not jump out 3 7 8 Retaining sheet Pull out the retaining sheet by hand Pull out the guide pins and extract the movable drive face from the fixed driven face ...

Page 65: ...e the inside diameter of the movable drive face Wear Limit Ø34 06mm 3 7 11 Spring Measure the free length of the movable driven face spring Replaced if the free length of spring is less than 135mm 3 7 12 Fixed driven face comp bearings Push out the old bearings and install the new one with the tube that has corresponding length and suitable diameter ...

Page 66: ... 5mm 3 7 14 Fitting Install the fixed driven face comp into the movable driven face comp Avoid to damage the lip of oil seal Install two O rings and apply grease to the groove of the cam then fit the guide pins Apply a little grease inside of the spring sheet and manually push the spring sheet in lightly and the install the spring and screw the central nut ...

Page 67: ...mbly Loose cooler tube tightening ring Starter arm tightening bolt Starter arm 8 clutch side cover tightening bolts Clutch side cover Gasket Pin Use universal wrench to hold drive plate and remove drive belt pulley assembly Belt ...

Page 68: ...pring Starter arm Starter cam assembly Inspection 1 Check if starter arm surface and collar are worn and damaged 2 Check if starter cam gear surface is worn and damage 3 Check if starter cam and starter arm loaded surface are worn and damaged ...

Page 69: ...starter axle gear should match mark on starter cam 4 Use special tool for starter arm spring assembly Rotate tool clockwise such that spring locking pin is positioned under crank case half moon location then assemble stop plate Note 1 Torque of starter arm spring plate tightening bolt 90 kg cm 2 Torque drive plate tightening nut 800 1000 kg cm 3 Torque of clutch side cover bolt 50 80 kg cm 4 Torqu...

Page 70: ...70 4 4 1 CHASSIS REMOVAL OF COVER BR8 Representative Figure ...

Page 71: ...et Leg Shield Fender Fixed Front Cover Handle Bar Under Leg Shield Side Lower Leg Shield Rear Leg Shield Lower Cautions 1 Do not damage cover of body panels while dismounting 2 Handle with care regarding lugs of to avoid damage dismounting 3 When remounting do not scratch or crash wiring 4 While assembling every lug shall be fixated effectively 5 While assembling make matching panels and their slo...

Page 72: ... Balls of the steering system broken 3 The conical base for steering ball bearings damaged 4 Bad curvature of the front fork comp 5 Bad curvature of the front wheel shaft or deviation of the tire 6 Insufficient tire pressure Straight driving impossible due to deviation of the steering wheel 1 Deviation of the front fork comp 2 Unequal working of the left and right shock absorber beside the front f...

Page 73: ...el bear or damaged bearing 4 Bad of worn tires Inefficient braking 1 Unclean or oily friction lining surface 2 Excessive wear of the friction lining 3 Deviated or deformed brake discs 4 Inefficient braking due to air resistance caused by air unduly existing in the braking system 5 Insufficient brake fluid 6 Deteriorated brake fluid 7 Brake fluid pipe clogged 8 Improper mounting of brake caliper bo...

Page 74: ...nting of wheels causing serious sway 3 Deformed brake disc 4 Clogged brake fluid pipe 5 Serious wear of the brake caliper lining 6 Serious damage of the grease seal of the brake caliper piston 7 Deteriorated brake fluid 8 Resistance due to air existing in the brake system ...

Page 75: ...ve mounting of wheel propeller shaft pieces Inefficient rear brake Drum type 1 Bad adjustment of the brake 2 Serious wear of the brake drum 3 Serious wear of the brake cam shaft 4 Serious wear of the friction face between the rear brake lining and the cam shaft 5 Wear of the rear brake lining 6 Unmatched parts in the chisel groove of brake arm Rear shock absorber too flexible 1 Absorber spring con...

Page 76: ... lining can contact Front wheel Inspection Check eccentricity and wear condition Note If eccentricity is higher than 0 2mm please replace with new one to ensure driving safety Speed meter gear assembly Inspection of Wheel Rim Put wheel rim on rotation stand Rotate the wheel slowly and use dial gauge to measure eccentricity Note 1 The transverse eccentricity should be within 3 0 mm If the condition...

Page 77: ...ssembly 1 Speed meter gear assemble fillister and wheel hub flange should be fully matched 2 The wheel hub flange fillister and front fork flange should be fully matched Note 1 Torque of rear wheel axle self lock nut 600 900 kg cm 2 Torque of brake clipper tightening bolt 210 250 kg cm 3 Torque of speed meter cable nut 60kg cm ...

Page 78: ...entricity should be within 3 0mm If the condition is poor please replace with new one 3 The lateral eccentricity should be within 3 0 mm If the condition is poor please replace with new one Brake lining assembly brake shoe brake shoe spring Inspection Use 3 points of Vernier calipers two ends and center to measure lining thickness If lining is badly worn and thickness less than 2 0 mm Please repla...

Page 79: ...le Assembly Assembly is in reverse order of disassembly procedures Watch Please apply thin layer of grease on contact area of cam axle pin and lining Do not apply too much grease Note 1 Torque of rear brake connecting rod bolt 50 80 kg cm 2 Torque of lock pin nut 250 270 kg cm 3 Torque of rear wheel self locking nut 600 900 kg cm ...

Page 80: ...attaching bolts on air filter Air filter Upper and lower attaching bolts on rear shock absorber Shock absorber Inspection Check if the shock absorber is worn scratched leaking or bent If its condition is poor please replace with new one Note Torque of shock absorber upper and lower attaching bolts 200 300 kg cm ...

Page 81: ...unused after discharge it may deteriorate and shorten service life It will become less efficient After usage of 2 3 years battery capacity will decrease It can be regained by recharging several times 4 When there is other loads while igniting if the voltage will rise again after an abrupt falling it is normal 5 If a battery is unused during a long time its energy storage will decrease by its auto ...

Page 82: ... in a new battery a voltage will be generated after a certain lapse of time If the voltage is not sufficient then a recharging is necessary A recharged new battery has necessarily a longer lifetime 12 The C D I of the ignition system shall not fall swinging and be shocked It is a cause of frequent breakdown Therefore a special precaution is necessary in its dismounting and remounting 13 Bad contac...

Page 83: ...g 2 Leaking of electrolyte 3 Defective separator causing short circuit between positive and negative plates 4 Defective battery terminals 5 Defective recharging system 6 Defective rectifier Excessive specific weight of electrolyte 1 Insufficient recharging 2 Leaking of electrolyte 3 Reaction between sulfuric acid and pole plates Too low capacity 1 Insufficient recharging 2 Pole plates react with s...

Page 84: ...ning of spark plugs 1 Defective of flywheel magneto 2 Defective high tension coil 3 Defective C D I 4 Defective spark plugs 5 Defective conductor contact breaking or short circuit for example a Conduction between flywheel magneto and C D I b Conduction between C D I and the main switch c Conduction between C D I and the high tension coil Engine not running smoothly 1 Defective ignition first circu...

Page 85: ...tact or too large resistance at connections 3 Fuse fused 4 Defective main switch 5 Defective front and rear brake switches 6 Defective starter motor switch 7 Defective starter motor relay 8 Defective starter motor 9 Circuitry conductor defective or broken 10 Starter motor drive pinion locked with the over speed clutch gear Weak drive of starter motor 1 Insufficient recharging of battery 2 Bad cont...

Page 86: ...by with and with Warning Battery releases explosive gas during charging or use battery Therefore it is dangerous to do so in concealed location Please put battery in good ventilation location during charging and forbid fire Note 1 Standard charging current 0 6 A for 5 10 hours 2 Quick charging current 6 0 A for 30 minutes 3 Please do not use quick charge except for emergency 4 Measure the battery ...

Page 87: ... check the main switch and wire harness for short circuit 5 4 RECTIFIER Watch 1 Check if wire harness is normal before checking rectifier and end resistor Check if rectifier socket is well connected 2 Keep fingers away from tester probe The circuit resistance can be changed with human body resistance involved Rectifier Terminal Resistance Table Meter Meter White Red Yellow Red Red Black White Red ...

Page 88: ...th the relay yellow red terminal B Connect the negative terminal with ground circuit and press the starter button Then check the electricity continuity Note 1 There should be continuity when pressing the start button 2 If there is no continuity when pressing the starter button then check the continuity between starter button and connecting cable C Check starter relay voltage Watch Please place mai...

Page 89: ...atch The battery voltage must satisfy requirement in checking starter voltage Note 1 If there is voltage then the relay is normal 2 If there is no voltage then check the continuity of brake switch and cable ...

Page 90: ...y turn the main switch to ON position and check if the motor has operated Disassembly 2 starter motor attaching bolts Starter motor Roll up the water proof rubber jacket and remove connector 2 motor case attaching bolts Motor commutator Front cover Check Starter Commutator Inspection 1 Check continuity between segments Note A If continuity is good then it is normal B If no continuity then it is br...

Page 91: ...s 4 Check the removed parts for damaging burning discoloration and wearing Replace with a new if necessary 5 Check brush length Note A Initial standard brush length is 112 5 mm B If brush length is smaller than 8 5 mm please replace with new brush Inspection Check continuity of the brush holder Note A If there is no continuity it is normal B If there is continuity it is broken Please replace with ...

Page 92: ...tor B Connect the megga meter s negative terminal with frame ground and measure the resistance Note 1 Standard resistance 0 2 1 0 Ohm 20o C 2 If the measured value exceed the standard replace with new A C generator charging coil B A C generator lighting coil Disassembly Disconnect the A C generator s 4P connector Measure A Use megga meter s positive terminal to connect the yellow wire of the 4P co...

Page 93: ... hold flywheel and remove lock nut Use the big end of flywheel remover and rotate counter clockwisely into flywheel Use universal wrench to hold flywheel and rotate the flywheel remover clockwisely to remove lock nut Then the flywheel can be removed Note The big end of flywheel remover is left threaded ...

Page 94: ...ly 2 The flywheel s fillister should match crankshaft pin Note 1 Torque of flywheel tightening bolt 550 kg cm 2 Torque of fan tightening bolt 90 kg cm 5 8 RESISTOR Disassembly Remove front windshield cover Measure A Use megga meter s positive terminal to connect resistor wire B Connect the megga meter s negative terminal with frame ground and measure the resistance Note Resistor standard 20 W 5 9 ...

Page 95: ...Ohm Primary Coil Black White Green 0 1 1 0 Ohm Secondary Coil Green Spark Plug Cap 7 12 k Ohm A Exciting Coil Inspection Disassembly The exciting coil connector Measure A Use megga meter s positive terminal to connect exciting coil s black red terminal B Connect the megga meter s negative terminal with frame ground and measure the Note 1 The standard resistance is 300 1000 Ohm 20o C 2 If the resis...

Page 96: ...s positive terminal to connect pulse coil s blue yellow terminal B Connect the megga meter s negative terminal with body ground and measure the resistance Note 1 The standard resistance 40 300 Ohm 20o C 2 If the resistance is higher than standard then it is broken Please replace with new one ...

Page 97: ... green terminal D Primary Coil Inspection Measure Connect the electric tester as Fig and measure the resistance Note 1 Standard resistance 0 1 1 0 Ohm 20o C 2 If the resistance is Infinity then the coil is broken Replace it with new one E Secondary Coil Inspection Measure Connect the electric tester with spark plug cable and ignition wire terminal as shown in Fig and measure the resistance Note 1 ...

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TGB BF8, Service Manual

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