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Summary of Contents for MB5 1982

Page 1: ...SHOP MANUAL MB5 ...

Page 2: ...s some warnings and caution against some specific service methods which could cause PERSONAL INJURY to service personal or could damage a vehicle or render it unsafe Please understand that those warnings could not cover all conceivable ways in which service whether or not recommended by Honda might be done or of the possible hazardous consequences of each conceivable way nore could Honda investiga...

Page 3: ...the trouble go to section 14 TROUBLESHOOTING ALL INFORMATION ILLUSTRATIONS DIRECTIONS AND SPECIFICATIONS IN CLUDED IN THIS PUBLICATION ARE BASED ON THE LATEST PRODUCT INFORMATION AVAILABLE AT THE TIME OF APPROVAL FOR PRINTING HONDA MOTOR CO LTO RESERVES THE RIGHT TO MAKE CHANGES AT ANY TIME WITHOUT NOTICE AND WITHOUT INCURRING ANY OBLIGA TION WHATEVER NO PART OF THIS PUBLICATION MAY BE REPRODUCED ...

Page 4: ... is stamped on the steering head right side The engine serial number is stamped on the left crankcase 2 The vehicle identification number VIN is near the steering head left side The carburetor identification number is on the carburetor body left side Date of Issue July 1981 HONDA MOTOR CO LTO ...

Page 5: ... not smoke or allow flames or sparks near the battery especially while charging it 1 Use geniune HONDA or HONDA recommended parts and lubricants or their equivalent Parts that do not meet HONDA s design specifications may damage the motorcycle 2 Use the special tools designed for this product 3 Use only metric tools when servicing this motorcycle Metric bolts nuts and screws are not interchangeabl...

Page 6: ... screw initial setting Float level 4 HONDA MBS 1 880 mm 74 0 in 705 mm 27 8 in 1 025 mm 40 4 in 1 215mm 47 8 in 750 mm 29 5 in 310 mm 12 2 in 160 mm 6 3 in 79 kg 1741b 90 kg 1981b Cross line backbone Telescopic fork Swingarm shock absorber 189 kg 416 71b 100 kg 220 51b 2 50 18 4PR Rib pattern 2 50 18 4PR Block pattern 175 kPa 1 75 kg cm2 25 psi 225 kPa 2 25 kg cm2 32 psi 125 mm 4 9 in 90 mm 3 5 in...

Page 7: ...light Tachometer light Neutral indicator Turn signal indicator High beam indicator Date of Issue July 1981 HONDA MOTOR CO LTD 5 GENERAL INFORMATION Wet multi plate 5 speed constant mesh 4 117 3 307 43 13 3 083 1 882 1 400 1 130 0 960 left foot operated return system 1 N 2 3 4 5 C D I 19 3 BTDC at 3 000 rpm 10 5 BTDC at 7 000 rpm Primary kickstarter AC generator 66W 5 000 rpm 12V 2 5 AH NGK BR8HS N...

Page 8: ...rshift pedal 1 6 8 12 0 8 1 2 6 9 Kickstarter pedal 1 6 8 12 0 8 1 2 6 9 Swingarm pivot nut 1 12 55 65 5 5 6 5 40 48 Self locking nut Front brake disc 3 8 27 33 2 7 3 3 20 24 Front brake master cylinder 2 6 10 14 1 0 1 4 7 10 Front brake master cylinder reservoir cap 4 4 1 2 0 1 0 2 0 7 1 5 Brake hose bolt 2 10 25 35 2 5 3 5 18 25 Brake caliper bracket 2 8 24 30 2 4 3 0 17 22 Brake caliper 1 8 20 ...

Page 9: ...1 0 07746 0020400 1 Front fork oil seal driver 07747 0010100 1 body Fork seal driver attachment 07747 0010300 1 B Pin spanner 07702 0010000 1 Shock compressor 07959 3290001 1 Date of Issue July 1981 HONDA MOTOR CO LTO GENERAL INFORMATION O ty Remarks Ref page 1 Crankshaft installation 9 11 1 Balancer installation 9 11 1 Removal of small balancer 9 6 bearing and mainshaft bearing 1 1 1 Main bearing...

Page 10: ...ENERAL INFORMATION CABLE HARNESS ROUTING 1 6 BRAKE HOSE TACHOMETER CABLE CLUTCH CABLE 8 HONDA MBS SPEEDOMETER CABLE THROTTLE CABLE CLUTCH CABLE TACHOMETER CABLE Date of Issue July 1981 HONDA MOTOR CO LTD ...

Page 11: ... HONDA MBS Date of Issue July 1981 HONDA MOTOR CO LTO CARBURETOR BREATHER TUBE GENERAL INFORMATION COl UNIT 9 1 7 ...

Page 12: ...NTROL LINKAGE I I WHEELS I I 3 12 TIRES I I I I 3 12 FRONT AND REAR SUSPENSION I I 3 12 STEERING HEAD BEARINGS I 3 13 BATTERY I I I I 3 7 LIGHTING EQUIPMENT I I I I 3 9 ALL NUTS BOLTS AND OTHER FASTENERS I I I I 3 13 CYLINDER HEAD PISTON DECARBONIZE c 6 2 CYLINDER EX PORT DECARBONIZE c 6 5 MUFFLER DECARBONIZE c 3 14 SHOULD BE SERVICED BY AN AUTHOR IZED HONDA DEALER UNLESS THE OWNER HAS PROPER TOOL...

Page 13: ... HONDA MBS Date of Issue July 1981 HONDA MOTOR CO LTO GENERAL INFORMATION MEMO 11 1 9 ...

Page 14: ...LUBRICATION OIL FLOW 2 0 12 HONDA MBS Engine oil _ Transmission oil Date of Issue July 1981 HONDA MOTOR CO l TO ...

Page 15: ...engine Do not attempt to disassemble the oil pump Bleed air from the oil pump if there is air in the oil pipe from the oil tank to the oil pump or if the oil pipe has been dis connected Bleed air from the oil pass tube from the oil pump to the inlet pipe if the tube has been disconnected SPECIFICATIONS INJECTOR OIL Oil capacity Oil recommendation Oil pump delivery Date of Issue July 1981 HONDA MOT...

Page 16: ...LESHOOTING Excessive smoke excessive carbon buildup in plug 1 Pump not properly synchronized excessive oil 2 Low quality of engine oil Overheating 1 Oil pump not synchronized properly insufficient oil 2 Low quality of engine oil Seized or burnt piston 1 No oil in tank or clogged oil pipe 2 Pump not properly synchronized insufficient oil 3 Air in oil pipe 4 Defective oil pump Oil not flowing out fr...

Page 17: ...temperature Remove the oil filler cap Remove the oil drain plug and drain the oil Reinstall the drain plug TORQUE 20 25 N m 2 0 2 5 kg m 14 18 ft lb CAUTION Make sure that the sealing washer on the drain plug is in good condition Refill the engine up to the proper level OIL CAPACITY 0 91it 1 0 US qt at change SPECIFIED OIL 10W 40 or equivalent Start the engine and check for leaks Stop the engine a...

Page 18: ...creen Clean the oil strainer screen with compressed air Installation of the oil strainer is the reverse order of removal Fill the oil tank with the recommended oil up to the proper level Bleed air from the oil pump and oil pipe Page 2 7 CAUTION Connect the oil pipe securely Check for leaks 2 4 16 HONDA MBS OIL STRAINER SCREEN OIL TUBE ___ 1 t CLIP OIL STRAINER JOINT w OIL TUBE 1 Date of Issue July...

Page 19: ...two bolts attaching the oil pump and remove the oil pump Disconnect the oil pipe from the oil pump and pinch the end of the oil pipe to prevent oil from flowing out Disconnect the oil pass tube from the inlet pipe NOTE Use care not to allow oil to flow out of the oil pass tube Date of Issue July 1981 HONDA MOTOR CO LTO LUBRICATION BOLTS 17 2 5 ...

Page 20: ... the oil pump NOTE Lubricate the 0 ring with clean grease before installation Make sure that the oil pump is inserted into the crankcase properly Tighten the oil pump attaching bolts securely Reconnect the oil pump control cable Reinstall the oil pipe and oil pass tube NOTE Perform the following inspections and adjust ments Control cable adjustment Page 3 6 Oil pump air bleeding Page 2 7 Oil pass ...

Page 21: ...at the top of the oil pump Tighten the bleeder bolt when the oil is free of air bubbles OIL PASS TUBE NOTE Bleed air from the oil pass tube when the tube is disconnected or there is air in the oil pipe and oil pump Make sure that there is fuel in the fuel tank 25 50 parts fuel to 1 part lubricant Start the engine and run it for about 10 minutes with the oil pump control lever in the fully open pos...

Page 22: ...ht glass float and oil level indicator from the oil tank OIL TANK LEVEL INDICATOR INSTAL LATION Clean the sight glass and install the float and level indicator in the tank so that the float can move up and down as shown Align the tab on the sight glass with the arrow on the tank and install it over the tank all the way Tighten the clip securely 2 8 20 HONDA MB5 O IL TANK BOLTS 0 1L STRAINER SCREEN...

Page 23: ... CLUTCH AND BRAKE or CABLE LUBRICANT LEVER PIVOTS SPEEDOMETER AND TACHOMETER CABLES LUBRICATION WHEEL BEARINGS WHEEL BEARINGS C HA 1 N_ L_ U_ B_ R1 C A NT l SPEEDOMETER DRIVE GEAR Date of Issue July 1981 HONDA MOTOR CO LTD CENTER STAND PIVOT 21 DRIVE CHAIN BRAKE PEDAL PIVOT 2 9 ...

Page 24: ...LUBRICATION MEMO 2 10 22 HONDA MB5 Date of Issue July 1981 HONDA MOTOR CO LTD ...

Page 25: ... plug For cold climate below 5 C 41 F ND NGK W22FSR BR7HS 3 INSPECTION AND ADJUSTMENT 3 1 CHASSIS BATTERY 3 3 FRONT BRAKE 3 3 REAR BRAKE 3 4 BRAKE LIGHT SWITCH 3 5 HEADLIGHT AIM 3 5 CLUTCH 3 6 DRIVE CHAIN 3 6 SUSPENSION 3 7 WHEELS STEERING HEAD BEARINGS NUTS BOLTS FASTENERS MUFFLER DECARBONIZING See page 2 3 See page 2 4 See page 6 2 See page 6 5 3 7 3 7 3 8 3 9 3 9 3 10 3 10 3 12 3 1 2 3 1 3 3 13...

Page 26: ...ze Front Rear Colt tire pressure Minimum tread depth 3 2 Front Rear Front Rear 19 3 BTDC at 3 000 rpm 5 000 7 000 rpm 10 5 BTDC at 9 000 rpm 1 400 rpm 1 3 8 turns out 130 kPa 13 0 kg em 185 psi 2 6 mm 1 8 1 4 in 20 30 mm 3 4 1 1 4 in 10 20 mm 3 8 3 4 in 10 20 mm 3 8 3 4 in 2 50 18 4PR 2 50 18 4PR 175 kPa 1 75 kg cm2 25 psi 225 kPa 2 25 kg cm2 32 psi 0 8 mm 1 32 in 0 8 mm 1 32 in 24 HONDA MBS Date ...

Page 27: ...throttle operation is not smooth Measure throttle grip free play at the throttle grip flange FREE PLAY 2 6 mm 1 8 1 4 in Adjustment can be made at either end of the throt tle cable Minor adjustments are made at the upper end and major adjustments are made at the lower end Adjust by loosening the lock nut and turning the adjuster Tighten the lock nut Recheck throttle operation Date of Issue July 19...

Page 28: ...solvent and allow to dry NOTE Do not wash the element in gasoline or vege table oil Soak the element in clean engine oil or gear oil SAE 80 90 and squeeze out any excess Install the element and retainer Install the right side cover 3 4 WASH IN SOLVENT 26 HONDA MBS RIGHT SIDE COVER ELEMENT RETAINER b SQUEEZE OUT SOLVENT THOROUGHLY 0 GEAR OIL SQUEEZE OUT EXCESS OIL Date of Issue July 1981 HONDA MOTO...

Page 29: ...park plug wrench to compress the plug washer Connect the spark plug cap CARBURETOR IDLE SPEED NOTE The engine must be warm for accurate idle adjustment Attach an engine tachometer Turn the throttle stop screw to obtain the specified idle speed IDLE SPEED 1 400 rpm When the engine misses or runs erratically proceed as follows Screw in the air screw until it lightly seats then turn it out 1 3 8 turn...

Page 30: ... mark toward the OPENregion Excessive white smoke or hard starting Pump control lever excessively open Burnt piston Pump control lever not opened properly IGNITION TIMING NOTE The CDI ignition timing is not adjustable If the ignition timing is incorrect check the CDI unit and alternator and replace any faulty parts Remove the left crankcase cover Connect a stroboscopic timing light to the high ten...

Page 31: ...l shorted the service life of the battery The battery electrolyte contains sulfuric acid Protect your eyes skin and clothing In case of contact flush thoroughly with water and calla doctor electrolyte Replace the battery if sulfation forms or sedi ments accumulate on the bottom FRONT BRAKE FLUID LEVEL Check the front brake fluid reservoir leveL If the level nears the lower level mark fill the rese...

Page 32: ... Refer to Section 12 CAUTION Always replace the brake pads in pairs to assure even disc pressure REAR BRAKE REARBRAKEPEDALPLAY Measure the brake pedal free play FREE PLAY 20 30 mm 3 4 1 1 4 in If adjustment is necessary turn the rear brake adjusting nut 3 8 30 HONDA MBS BRAKE PADS DISC ADJUSTING NUT 20 30mm 3 4 H 4 in Date of Issue July 1981 HONDA MOTOR CO LTD ...

Page 33: ... turning the switch adjusting nut as shown HEADLIGHT AIM Adjust IJertically by loosening both headlight case mounting bolts Adjust horizontally by turning the adjusting screw on the headlight rim Turn the adjusting screw clockwise to direct the beam toward the left side of the rider NOTE Adjust the headlight beam as specified by local laws and regulations An improperly adjusted headlight may blind...

Page 34: ...e play by loosening the lock nut and turn ing the adjusting nut until the free play is 10 20 mm 3 8 3 4 in DRIVE CHAIN INSPECTION Shift the transmission into neutral Measure the drive chain slack between the sprock ets CHAIN SLACK 10 20 mm 3 8 3 4 in 3 10 ADJUSTING NUT 32 HONDA MBS LOCK NUT Date of Issue July 1981 HONDA MOTOR CO LTD ...

Page 35: ...ry Inspect the drive chain for possible wear or damage Replace any chain that is damaged o r excessively worn Inspect the sprocket teeth for excessive wear or damage Replace if necessary CAUTION Never install a new drive chain on worn sprockets or a worn chain on new sprockets Both chain and sprockets must be in good condition or the new replacement chain or sprockets will wear rapidly NOTE Commer...

Page 36: ...vely worn Page 11 12 Check the shock absorbers for leaks or damage Tighten all rear suspension nuts and bolts WHEELS NOTE Tire pressure should be checked when tires are COLD Check the tires for cuts imbedded nails or other sharp objects RECOMMENDED TIRE PRESSURE AND TIRE SIZE Cold tire Pressures Front 175 1 75 25 kPa kg cm2 psi Rear 225 2 25 32 Vechicle capacity load 100 kg 220 lbs Front Tire size...

Page 37: ...that all chassis nuts and bolts are tightened to correct torque values Check all cotter pins and safety clips MUFFLER DECARBONIZING Remove the diffuser pipe attaching screw and collar Remove the diffuser pipe from the muffler Clean the diffuser pipe with a bristle wi re brush Remove carbon from inside the muffler CAUTION Do not heat or clean with solvent in an at tempt to remove carbon from the mu...

Page 38: ...HONDA FUEL SYSTEM MBS 4 0 36 Date of Issue July 1981 HONDA MOTOR CO LTD ...

Page 39: ...line Alway s work in a well ventilated area and away from sparks or flames The float bowl has a drain plug that can be loosened to drain residual fuel When disassembling fuel system parts note the locations of the 0 rings Replace them during assembly TOOL Common Float Level Gauge SPECI FI CATIONS Venturi dia Setting mark Main jet Main air jet Jet needle Slow jet Float level Air screw opening Idle ...

Page 40: ...3 Low compression 4 Rich mixture 5 Lean mixture 6 Air cleaner clogged 7 Air leaking into inlet pipe 8 Fuel contaminated 4 2 Lean mixture 1 Carburetor fuel jets clogged 2 Fuel cap vent clogged or blocked 3 Fuel filter clogged 4 Fuel line kinked or restricted 5 Float valve faulty 6 Float level too low 7 Air vent tube clogged Rich mixture 1 Choke stuck closed 2 Faulty float valve 3 Float level too hi...

Page 41: ... Loosen the tube band Remove the nuts attaching the carburetor to the engine inlet pipe Disconnect the clutch cable Disconnect the tachometer cable Disconnect the air vent tube Remove the carburetor from the engine NOTE Keep dust and dirt from entering the carbu retor and cylinder Date of Issue July 1981 HONDA MOTOR CO LTD FUEL SYSTEM FUEL TUBE FUEL VALVE DRAIN TUBE AIR VENT TUBE CLUTCH CABLE TACH...

Page 42: ...ottle valve Remove the return spring carburetor top and sealing cap Pry off the cable clip and remove the jet needle Check the jet needle and throttle valve for wear or damage 4 4 THROTTLE CABLE JET NEEDLE THROTTLE VALVE 40 HONDA MBS SEALING CAP RETURN SPRING CABLECUP Standard position 2nd groove Date of Issue July 1981 HONDA MOTOR CO LTO ...

Page 43: ... or damage Check the float for deformation or presence of fuel Remove the main jet needle jet holder and needle jet Remove the stop screw and air screw NOTE Before removing either screw record the num ber of turns until the screw lightly rests bottoms This allows the screw to be rest to its original position Remove the choke starter valve Date of Issue July 1981 HONDA MOTOR CO LTD FLOAT FUEL SYSTE...

Page 44: ...rt for wear or damage Inspect the choke starter valve The knob should be held securely when pulled out fully JETS FLOAT VALVE FLOAT ASSEMBLY Install the needle jet needle jet holder and main jet Install the air and stop screws by turning them into their original positions 4 6 THREADS KN HONDA MB5 MAIN JET NEEDLE JET HOLDER NEEDLE JET STOP SCREW AIR SCREW Date of Issue July 1981 42 HONDA MOTOR CO L...

Page 45: ...oat level with the float tip just con tacting the float valve FLOAT LEVEL 13 5 mm 0 53 in 1 0 mm Replace the float assembly if not within specifica tion THROTTLE VALVE CABLE INSTALLATION Install the jet needle on the throttle valve and secure with the cable clip Date of Issue July 1981 HONDA MOTOR CO LTD FLOAT PIN 43 FLOAT VALVE CHOKE STARTER VALVE CABLE CLIP JET NEEDLE FUEL SYSTEM FLOAT FLOAT GAU...

Page 46: ...ly tighten the top This could cause distortion and malfunction CARBURETOR INSTALLATION Carburetor installation is essentially the reverse order of removal Perform the following after installing the carbu retor Clutch lever free play adjustment page 3 10 Carburetor adjustment page 3 5 Oil pump control cable adjustment page 3 6 4 8 SEALING CAP THROTTLE VALVE THROTTLE VALVE HONDA MBS CARBURETOR TOP R...

Page 47: ...toplight and rear turn signal wires from the wire harness at the connector Remove the fuel tank rear mounting bolts Remove the oil tank cover Remove the fuel tank front mounting bolts Turn the fuel cock to OF F and disconnect the fuel line Remove the fuel tank INSPECTION Check the vent hole of the filler cap for blockage Date of Issue July 1981 HONDA MOTOR CO LTD FUEL SYSTEM WIRE HARNESS CLAMP WIR...

Page 48: ...eps FUEL STRAINER Keep gasoline aK YJy from flames or sparks Wipe up spilledgasoline at once Check that fuel is flowing out of the fuel valve freely If fuel flow is restricted clean the fuel strainer NOTE IDo not overtighten the fuel valve lock nut Make sure there are no fuel leaks 4 10 46 HONDA MB5 FUEL STRAINER SCREEN o LOCK NUT Date of Issue July 1981 HONDA MOTOR CO LTD ...

Page 49: ...ngine hanger bolt and collar Remove the right and left screws and washers at taching the rear fender B and remove the rear fender B toward the wheel Remove the rear wheel Page 12 3 Remove the bolt attaching the air cleaner case to the frame and remove the case toward the wheel Clean the air cleaner element Page 3 4 Date of Issue July 1981 HONDA MOTOR CO LTO 47 FUEL SYSTEM BATTERY A I R CLEANER REA...

Page 50: ...ENGINE REMOVAL INSTALLATION 25 35 N m 2 5 3 5 kg m 18 25 ft lb 5 0 48 HONDA MBS f l rr N m _3 0 4 0 kg m 22 29 ft lb 8 12 N m 0 8 1 2 kg m 6 9 ft lb Date of Issue July 1981 HONDA MOTOR CO LTO ...

Page 51: ...earshift linkage Kickstarter SPECIFICATIONS Engine dry wei Jt Transmission oil capacity TORQUE VALUES Engine hanger bolt Foot peg mounting bolt Rear axle nut Gearshift pedal bolt Date of Issue July 1981 HONDA MOTOR CO LTD Carburetor 17 5 kg 38 6 Ib 1 0 Iit 1 1 US qt at engine assembly 0 9 lit 1 0 US qt at change 30 40 N m 3 0 4 0 kg m 22 29 ft lb 25 35 N m 2 5 3 5 kg m 18 25 ft lb 55 65 N m 5 5 6 ...

Page 52: ...il control cable Disconnect the oil pipe from the oil pump and pinch the end of the oil pipe to prevent oil from flowing out Disconnect the alternator wire connectors Remove the carburetor flange nuts 5 2 HONDA MB5 OIL CONTROL CABLE OIL PIPE ALTERNATOR WIRE CONNECTORS NUT CARBURETOR Date of Issue July 1981 50 HONDA MOTOR CO LTO ...

Page 53: ... the axle nut Carefully remove the drive chain master link retain ing clip and remove the drive chain Remove the brake pedal return spring Remove the foot peg by removing the two mount ing bolts Date of Issue July 1981 HONDA MOTOR CO lTD ENGINE REMOVAL INSTALLATION LEFT CRANKCASE COVER DRIVE CHAIN RETAINING CLIP FOOT PEG 51 5 3 ...

Page 54: ...INE REMOVAL INSTALLATION Remove the spark plug cap Disconnect the clutch and tachometer cables Remove the muffler 5 4 52 HONDA MB5 SPARK PLUG CAP TACHOMETER CABLE Date of Issue July 1981 HONDA MOTOR CO LTD ...

Page 55: ...age 2 3 Check the locations of the cables and pipes Page 1 6 Bleed air from the oil pump Page 2 8 Adjust the oil pump control cable Page 3 6 Adjust the clutch lever free play Page 3 10 Install the drive chain master link properly Page 3 11 Adjust the drive chain tension Page 3 10 Date of Issue July 1981 HONDA MOTOR CO LTO ENGINE REMOVAL INSTALLATION ENGINE MOUNTINQ BOLTS 30 40 N m 3 0 4 0 kg m 22 ...

Page 56: ...CYLINDER HEAD CYLINDER PISTON 6 0 54 HONDA MB5 8 12 N m 0 8 1 2 kg m 6 9 ft lb Date of Issue July 1981 HONDA MOTOR CO LTD ...

Page 57: ...iston clearance Piston pin bore Piston pin 0 D Piston to piston pin clearance Piston ring end gap top second Connecting rod small end I D TROUBLESHOOTING Compression too low hard starting or poor performance at low speed 1 Blown cylinder head gasket 2 Loose spark plug 3 Worn stuck or broken piston rings 4 Worn or damaged cylinder and piston 5 Faulty reed valve Compression too high overheating or k...

Page 58: ...r INSPECTION Check the cylinder head for warpage with a straight edge and feeler gauge in the directions shown SERVICE LIMIT 0 10 mm 0 004 in DECARBONIZING Remove the carbon deposits from the combustion chamber Clean the head gasket surface of any gasket mate rial NOTE IAvoid damaging the gasket surfaces 6 2 56 r iJ HON DA MB5 SPARK PLUG CAP Date of Issue July 1981 HONDA MOTOR CO LTD ...

Page 59: ...EMOVAL Remove the cylinder head Page 6 2 and exhaust pipe Remove the four flange bolts attaching the intake pipe to the cylinder NOTE Do not remove the oil pass tube or locate the end of the tube lower than the oil pump Bleed air from the oil pass tube when it has been disconnected or the end has been located lower than the oil pump Date of Issue July 1981 HONDA MOTOR CO LTD 57 CYLINDER HEAD CYLIN...

Page 60: ...pliers Press the piston pin free of the piston NOTE Do not damage or scratch the piston Do not apply force in the piston pin direc tion Do not let the clip fall into the crankcase Do not re use the piston pin clips PISTON RING EXPANDER REMOVAL Spread each piston ring and remove by lifting it up at a point just opposite the gap Remove the expander 6 4 HONDA MBS CYLINDER PISTON PiN CLIP PISTON PIN E...

Page 61: ...evels in X and Y directions Take the minimum figure measured to determine the cylinder wear Avoid the port area SERVICE LIMIT 39 070 mm 1 5382 in Measure the O D of the piston at a point 10 mm 3 8 in from the end of the skirt SERVICE LIMIT 38 920 mm 1 5323 in Calculate the piston to cylinder clearance SERVICE LIMIT 0 100 mm 0 0039 in Date of Issue July 1981 HONDA MOTOR CO LTO 59 CYLINDER HEAD CYLI...

Page 62: ...om using the piston and measure the end gap SERVICE LIMITS TOP 0 35 mm 0 014 in SECOND 0 35 mm 0 014 in Install the expander in the second groove of the piston Install the top and second rings Page 6 7 NOTE Press each piston ring into place at several points to make sure that it is flush with the piston surface If not clean carbon deposits from the ring groove They should be free enough to be rota...

Page 63: ...nd rings are interchange able with each other Do not mix different brands of rings in an engine Do not replace one without replac ing another Install the connecting rod small end bearing piston and piston pin NOTE Install the piston with the IN marking facing the inlet side Dip the small end bearing and piston pin in clean oil before installation Install new piston pin clips NOTE IDo not let the c...

Page 64: ...linder head and new cylinder head gasket Page 6 3 Install the reed valve and intake pipe Install the exhaust muffler Install the cylinder head hanger bolts Perform the following inspections and operation Cylinder compression Page 3 7 compression leaks Engine noise Secondary air leaks Air bleeding from oil pass tube Page 2 7 REED VALVE REMOVAL Remove the intake pipe Page 6 3 Remove the reed valve 6...

Page 65: ...as this may cause improper engine perfor mance The reed valve must not be disas sembled If the stopper reed or seat is defec tive replace all as a unit INSTALLATION Installation of the reed valve is essentially the reverse order of removal CAUTION IBleed airfrom the oil pass tube Page 2 7 After installation check for secondary air leaks Date of Issue July 1981 HONDA MOTOR CO LTD REED STOPPER REEDS...

Page 66: ...ER SHIFT LINKAGE 8 12N m 0 8 1 2kg m _ 6 9ft lb t1Jff r 1 8 7 0 HONDA MBS 8 12 N m 0 8 1 2 kg m 6 9 ft lb 45 55 N m 4 5 5 5 kg m 33 40 ft lb 8 12 N m 0 8 1 2 kg m 6 9 ft lb Date of Issue July 1981 64 HONDA MOTOR CO LTO ...

Page 67: ...lb 7 9 7 10 7 13 ITEM STANDARD mm in SERVICE LIMIT mm in Clutch spring free length preload Clutch disc thickness Clutch plate warpage Clutch outer I D Kickstarter spindle 0 D Kickstarter pinion I D Kickstarter idle gear Countershaft O D Gear I D Oil pump driven gear shaft 0 D Balancer idler gear shaft O D TROUBLESHOOTING Clutch slips when accelerating 1 No free play 2 Discs worn 3 Springs weak Clu...

Page 68: ...onnect the tachometer cable Remove the bolts attaching the right crankcase cover and remove the right crankcase cover DISASSEMBLY Remove the clutch lifter rod then remove the clutch arm Check the 0 ring for damage fatigue or other faults Check the clutch arm for bending 7 2 CLUTCH CABLE CLUTCH LIFTER ROD 66 HONDA MBS TACHOMETER CABLE Date of Issue July 1981 HONDA MOTOR CO LTD ...

Page 69: ...LATION Install the clutch arm and clutch lifter rod Install the tachometer gear on the right crankcase cover Install the dowel pins and gasket on the crankcase Date of Issue July 1981 HONDA MOTOR CO LTO 67 CLUTCH KICKSTARTER SHIFT LINKAGE OIL SEAL WASHERS _____ DOWEL PINS TACHOMETER GEAR 7 3 ...

Page 70: ...e steps Connect the tachometer and clutch cables Install the kickstarter pedal Fill the transmission with recommended oil Page 2 3 Adjust the clutch lever free play Page 3 10 CLUTCH IDLER GEAR CLUTCH REMOVAL Remove the right crankcase cover Page 7 2 Remove the clutch lifter plate and clutch springs by removing the bolts 7 4 68 HONDA MBS RIGHT CRANKCASE COVER LIFTER PLATE Date of Issue July 1981 HO...

Page 71: ...SPECTION Measure each clutch spring free length SERVICE LIMIT 28 5 mm 1 12 in CLUTCH DISC INSPECTION Replace the clutch discs if they show signs of scor ing or discoloration Measure each clutch disc thickness SERVICE LIMIT 2 50 mm 0 098 in Date of Issue July 1981 HONDA MOTOR CO LTD 69 CLUTCH DISCS CLUTCH KICKSTARTER SHIFT LINKAGE PRESSURE PLATE CLUTCH PLATES SPLINE WASHER 7 5 ...

Page 72: ...eck the slots in the outer drum for nicks cuts or indentations made by the friction discs Measure the clutch outer I D SERVICE LIMIT 17 060 mm 0 6717 in BALANCER IDLER GEAR OIL PUMP DRIVEN GEAR REMOVAL Remove the clutch then remove the balncer idler gear and oil pump driven gear 7 6 OIL PUMP DRIVEN GEAR 70 HONDA MB5 BALANCER IDLER GEAR Date of Issue July 1981 HONDA MOTOR CO LTD ...

Page 73: ...damage Check the idler gear shaft for bending wear or damage Measure the balancer idler gear shaft O D at two places as shown SERVICE LIMIT 9 930 mm 0 3909 in Check the oil pump driven gear for wear or damage Check the oil pump driven gear shaft for cracks or other defects Replace the shaft and gear with new ones if cracked Measure the oil pump driven gear shaft O D SERVICE LIMIT 9 930 mm 0 3909 i...

Page 74: ...PRIMARY DRIVE GEAR INSTALLATION Install the collar on the crankshaft then install the primary drive gear NOTE Align the punch mark on the end of the crankshaft with the punch mark on the gear Install the washer and 12 mm nut on the end of the crankshaft Hold the flywheel with the UNIVER SAL HOLDER and tighten the 12 mm nut to the specified torque TORQUE 45 55 N m 4 5 5 5 kg m 33 40 ft lb 7 8 SLOT ...

Page 75: ...line on the balanc er gear is in line with the mating line on the shaft Install the clutch outer without disturbing the setups in steps 1 and 2 Rotate the clutch outer right or left until the gear engages the sub gear then push it in the crankcase Make sure that the sub gear engages the clutch outer gear properly Date of Issue July 1981 HONDA MOTOR CO LTO 73 PRIMARY DRIVE GEAR SUB GEAR CLUTCH KICK...

Page 76: ...nsmission oil Page 2 3 6mmBOLT CLUTCH SPRING L LIFTER PLATE CLUTCH OUTER KICKSTARTER SPINDLE REMOVAL Remove the right crankcase cover Page 7 2 Remove the clutch assembly Page 7 4 NOTE It is not necessary to remove the clutch to remove the kickstarter spindle Remove the kick return spring from the ratchet guide plate then remove the kickstarter spindle 7 10 CLUTCH DISCS 74 HONDA MBS PRESSURE PLATE ...

Page 77: ... washer INSPECTION Measure the kickstarter spindle 0 0 SERVICE LIMIT 11 950 mm 0 4704 in Measure the kick pinion gear 1 0 SERVICE LIMIT 12 070 mm 0 4752 in Date of Issue July 1981 HONDA MOTOR CO LTO CLUTCH KICKSTARTER SHIFT LINKAGE 15 mm THRUST RETURN SPRING COLLAR WASHER KICKSTARTER 75 SPINDLE PINION GEAR RATCHET GUIDE PLATE KICKSTARTER PINION GEAR KICKSTARTER SPINDLE 7 11 ...

Page 78: ...cified torque TORQUE 8 12 N m 0 8 1 2 kg m 6 9 ft lb CAUTION Do not mix the 15 mm thrust washer 0 5 mm thick and kick spindle 15 mm thrust washer 1 0 mm thick Install the kickstarter in the reverse order of dis assembly CAUTION Slide the ratchet over the kickstarter spindle with the punch mark on the ratchet aligned with the spring hole in the spindle Do not confuse the 15 mm washer 1 0 mm thich w...

Page 79: ...ssion with the recommended oil up to the proper level Page 2 3 Check the operation of the kickstarter SHIFT LINKAGE REMOVAL Remove the clutch Page 7 4 Remove the kickstarter idler gear Page 7 12 Remove the bolt attaching the clutch stopper arm and remove the stopper arm and spring Date of Issue July 1981 HONDA MOTOR CO LTO DRIVE RATCHET CLUTCH KICKSTARTER SHIFT LINKAGE RATCHET GUIDE PLATE KICKSTAR...

Page 80: ...pindle INSPECTION Perform the following operations Check the shift arm spring for weakness Check the shift return spring for weakness Check the stopper spring for weakness Check the shift spindle for wear or bending 7 14 SHIFT ARM SPRING 78 HONDA MBS DRUM CAM PLATE BOLT SHIFT SPINDLE SHIFT RETURN SPRING STOPPER SPRING A Date of Issue July 1981 HONDA MOTOR CO LTD ...

Page 81: ... the plate with the bolt Tighten the bolt to the specified torque TORQUE 8 10 N m 0 8 1 2 kg m 6 9 ft lb Install the stopper arm and stopper spring in the crankcase and tighten the attaching bolt to the specified torque TORQUE 8 12 N m 0 8 1 2 kg m 6 9 ft lb Check the operation of the shift linkage With the balancer properly timed install the clutch Page 7 9 Install the right crankcase cover Page ...

Page 82: ...ALTERNATOR 50 60 N m 5 0 6 0 kg m 36 43 ft lb 8 0 80 HONDA MBS Date of Issue July 1981 HONDA MOTOR CO LTD ...

Page 83: ...iced without removing it from the motorcycle Do not remove the pulse generator from the stator base For alternator inspection refer to Section 13 TOOLS Common Universal Holder Flywheel Puller TORQUE VALUE Alternator rotor nut Date of Issue July 1981 HONDA MOTOR CO LTO 07725 0010101 Alternate tool 07725 0030000 07733 0010000 50 60 N m 5 0 6 0 kg m 36 43 ft lb 81 8 1 ...

Page 84: ...nk case cover Remove the 12 mm nut attaching the flywheel Remove the flywheel NOTE Keep the woodruff key in a parts rack so it is not lost 8 2 HONDA MBS LEFT CRANKCASE COVER UNIVERSAL HOLDER NUT ROTOR PULLER ALTERNATOR ROTOR FLYWHEEL Date of Issue July 1981 82 HONDA MOTOR CO LTO ...

Page 85: ... is removed Remove the alternator CAUTION Do not separate the pulse generator from the stator base Keep the coils in a parts rack to prevent damaging the coil For alternator inspection refer to page 13 5 and 13 7 Date of Issue July 1981 HONDA MOTOR CO LTD ALTERNATOR CONNECTORS CLAMP NEUTRAL SWITCH WIRE LEAD ALTERNATOR STATOR PULSE GENERATOR 83 8 3 ...

Page 86: ...to install the wire Install the woodruff key in the crankshaft keyway then install the flywheel on the crankshaft NOTE Check that there are no foreign materials inside the flywheel before installation Clean the taper hole in the flywheel of burrs and other damage and repair if neces sary TORQUE 50 60 N m 5 0 6 0 kg m 36 43 ft lb 8 4 ALIGNMENT LINE CONNECTORS CLAMP HONDA MB5 INDEX MARK NEUTRAL SWIT...

Page 87: ...ar over the switch Install the left crankcase cover NOTE Make sure that the alternator and neutral switch wires are not interfering with the flywheel Do not pinch the wires between the left crankcase cover and case Date of Issue July 1981 HONDA MOTOR CO LTO ALTERNATOR TIMING LIGHT NEUTRAL SWITCH COLLAR LEFT CRANKCASE COVER 85 8 5 ...

Page 88: ...CRANKSHAFT TRANSMISSION 9 0 86 r iiJ HONDA MBS Date of Issue July 1981 HONDA MOTOR CO LTD ...

Page 89: ...ston Clutch kickstarter gearshift linkage Alternator TOOLS Special Crankshaft Assembly Tool Balancer Weight Driver Bearing Remover Set Bearing Puller Attachment 28 x 30 mm Common Driver A Attachment 32 x 35 mm Attachment 42 x 47 mm Pilot 12 mm Pilot 17 mm Pilot 20 mm Driver B Attachment 20 mm I D Date of Issue July 1981 HONDA MOTOR CO LTO See section 2 See section 6 See section 7 See section 8 079...

Page 90: ...T mm in 10 000 10 018 0 3937 0 3944 10 05 0 396 4 93 5 00 0 194 0 197 4 50 0 177 9 972 9 987 0 3926 0 3932 9 95 0 392 12 934 12 984 0 5092 0 5112 12 85 0 506 35 950 35 975 1 4154 1 4163 35 90 1 413 17 016 17 034 0 6699 0 6706 17 10 0 673 17 016 17 034 0 6699 0 6706 17 10 0 673 16 522 16 543 0 6505 0 6513 16 60 0 654 19 520 19 541 0 7685 o 7693 19 60 0 772 19 020 19 041 0 7488 0 7496 19 10 0 752 16...

Page 91: ... not pry between the right and left cases TRANSMISSION DISASSEMBLY GEARSHIFT FORK SHIFT DRUM Remove the shift fork shaft from the right crank case Remove the shift drum and shift forks Date of Issue July 1981 HONDA MOTOR CO LTO LEFT CRANKCASE SHIFT DRUM 89 CRANKSHAFT TRANSMISSION DRIVE SPROCKET 4 RIGHT CRANKCASE SHIFT FORK SHAFT SHIFT FORKS llf 9 3 ...

Page 92: ...Claw thickness I D 4 50 mm 0 177 in 10 05 mm 0 396 in Check the shift fork shaft for wear damage or bending Measure the O D SERVICE LIMIT 9 95 mm 0 392 in Inspect the shift drum grooves and replace the drum if they are damaged or show excessive wear Measure the shift drum O D SERVICE LIMITS A 12 85 mm 0 506 in 8 35 90 mm 1 413 in 9 4 8 90 HONDA MBS Date of Issue July 1981 HONDA MOTOR CO LTD ...

Page 93: ...teeth for excessive or abnormal wear or evidence of insufficient lubri cation Measure the 1 0 of each gear SERVICE LIMIT M4 M5 gears C1 gear C2 gear C3 gear 17 10 mm 0 673 in 16 60 mm 0 654 in 19 60 mm 0 772 in 19 10 mm 0 752 in Date of Issue July 1981 HONDA MOTOR CO LTO MAINSHAFT 91 CRANKSHAFT TRANSMISSION COUNTERSHAFT 9 5 ...

Page 94: ...PLACEMENT Remove the balancer weight left bearing and main shaft left bearing from the left crankcase with the special tools as shown Remove the countershaft left bearing from the left crankcase Remove the mainshaft right bearing from the right crankcase 9 6 A HONDA MBS MAINSHAFT B COUNTE RSHAFT BALANCER WEIGHT COUNTERSHAFT LEFT BEARING MAINSHAFT LEFT BEARING 92 SPINDLE ASSEMBLY 1660100 BALANCER W...

Page 95: ...bearing Driver A Attachment 28 mm 07746 1870100 CRANKSHAFT REMOVAL Drive the carnkshaft out of the right crankcase NOTE Use a plastic or brass hammer Screw a nut onto the crankshaft end to prevent damage Protect the crankcase mating surface by resting it on a wooden block Date of Issue July 1981 HONDA MOTOR CO LTO 93 COUNTERSHAFT LEFT BEARING MAINSHAFT RIGHT BEARING CRANKSHAFT TRANSMISSION BALANCE...

Page 96: ...ICE LIMIT 0 85 mm 0 033 in Measure the connecting rod big end radial clearance at two points in the X and Y directions SERVICE LIMIT 0 05 mm 0 002 in Set the crankshaft on a stand or V blocks and read runout using a dial gauge SERVICE LIMIT 0 10 mm 0 004 in 9 8 94 r i J HONDA MBS X Date of Issue July 1981 HONDA MOTOR CO LTD ...

Page 97: ...he special tool bearing puller under the bearing securely and pull the bearing off NOTE IThe bearing puller is commercially available Remove the oil seal and drive out the right bearing from the right crankcase Date of Issue July 1981 HONDA MOTOR CO LTD BEARING PULLER 07631 0010000 OIL SEAL 95 PLAY CRANKSHAFT TRANSMISSION RADIAL RIGHT BEARING 9 9 ...

Page 98: ...N Do not support the right crankshaft when driving the bearing CRANKSHAFT INSTALLATION Wash the right and left crankcases in solvent and blow dry with a compressed air Check for cracks or other defects NOTE Apply clean engine oil to all moving and sliding surfaces except those in the crank chamber Remove all traces of gasket material from the gasket surfaces Remove roughness or irregularities if a...

Page 99: ...with grease TRANSMISSION ASSEMBLY Drive the balancer weight in the right crankcase while rotating the driver tool to prevent tilting the balancer bearing Apply oil to the gears before installing the mainshaft and countershaft Make sure the gears rotate freely Date of Issue July 1981 HONDA MOTOR CO LTO 97 CRANKSHAFT TRANSMISSION BALANCER WEIGHT DRIVER 07945 1660000 9 11 ...

Page 100: ...nd shift fork shaft Position the shift drum in neutral as shown Make sure that the mainshaft and countershaft rotate freely CRANKCASE ASSEMBLY Install a new gasket and two dowel pins 9 12 MAINSHAFT SHIFT DRUM HONDA MB5 COUNTERSHAFT SHIFT FORK SHAFT SHIFT FORKS DOWEL PINS GASKET Date of Issue July 1981 98 HONDA MOTOR CO LTO ...

Page 101: ...kcase onto the right crankcase Tighten the crankcase bolts in a crisscross pattern Install the drive sprocket Date of Issue July 1981 HONDA MOTOR CO LTO 99 LEFT CRANKCASE RIGHT CRANKCASE CRANKSHAFTI TRANSMISSION DR IVE SPROCKET 9 13 ...

Page 102: ...30 N m 2 0 3 0 kg m 15 22 ft lb 55 65 N m 5 5 6 5 kg m 40 48 ft lb 10 0 100 HONDA MBS 60 90 N m 6 0 9 0 kg m 43 65 ft lb 60 70 N m 6 0 7 0 kg m 43 51 ft lb 8 12 N m 0 8 1 2 kg m 6 9 ft lb 9 13 N m 0 9 1 3 kg m 7 9 ft lb Date of Issue July 1981 HONDA MOTOR CO LTD ...

Page 103: ...axle nut Front fork socket bolt Front fork inner bolt Front fork bolt Top bridge pinch bolts Bottom bridge pinch bolts Steering stem nut Date of Issue July 1981 HONDA MOTOR CO LTD Alternate 07917 3230000 MP310 277 91774 07944 1150001 07749 0010000 07746 0010200 07746 0040200 o7747 0o1o1oo I 07747 0010300 07747 1180001 07702 0010000 M9361 412 099788 8 12 N m 0 8 1 2 kg m 6 9 ft lb 10 14 N m 1 0 1 4...

Page 104: ...rbers 2 Bent front forks 3 Bent front axle wheel installed incorrectly Front wheel wobbling 1 Axle not tightened properly 2 Distorted rim 3 Worn front wheel bearing 4 Distorted spoke 5 Faulty tire Soft suspension 1 Weak fork spring 2 Weak fork spring 2 Insufficient fluid in front forks 10 2 FRONT WHEEL SUSPENSION 72 5 77 5 cc 2 5 2 6 oz 475 STANDARD mm in SERVICE LIMIT mm in 102 0 20 0 008 2 0 0 0...

Page 105: ... the punch marks on the headlight case with the index marks on the bracket INSTRUMENTS INDICATOR AND METER BULB RE PLACEMENT Remove the headlight and headlight case Remove the instrument lower cover attaching screws and lower cover Date of Issue July 1981 HONDA MOTOR CO LTD FRONT WHEEL SUSPENSION INSTRUMENT LOWER COVER 103 10 3 ...

Page 106: ...he speedometer and tachometer cables Remove the bulb holders from the instruments Remove the instrument mounting nuts and remove the instruments Install the instruments in the reverse order of removal HANDLEBAR REMOVAL Remove the headlight case Page 1Q 3 Remove the instrument lower cover Page 10 3 Disconnect the handlebar switch wires 10 4 TACHOMETER CABLE 104 HONDA MBS SPEEDOMETER CABLE Date of I...

Page 107: ... bands Remove the left handlebar switch Disconnect the clutch cable Remove the brake master cylinder Remove the right handlebar switch and throttle grip Date of Issue July 1981 HONDA MOTOR CO LTD FRONT WHEEL SUSPENSION 105 10 5 ...

Page 108: ...l the switch Tighten the upper screw first then tighten the lower screw Place the handlebar onto the lower holder by aligning the punch mark with the upper face of the lower holder Place the upper holders on the handlebar with the punch marks facing the front Tighten the forward bolts first then tighten the rear bolts TORQUE 8 12 N m 0 8 12 kg m 6 9 ft lb 10 6 106 HONDA MB5 LOCATING PIN Date of Is...

Page 109: ...the front master cylinder with the UP mark facing up Align the end of the holder with the handlebar punch mark Tighten the upper bolt first then the lower TORQUE 10 14N m 1 0 1 4 kg m 7 9 ft lb Route the switch wires Page 1 6 Connect the switch wires Install the instrument lower cover and headlight Date of Issue July 1981 HONDA MOTOR CO LTD FRONT WHEEL SUSPENSION HOLE LOCATING PIN UP MARK PUNCH MA...

Page 110: ...ause difficulty in fitting the brake disc between the brake pads AXLE INSPECTION Set the axle in V blocks rotate and measure the runout Actual runout is 1 2 of the total indicator reading SERVICE LIMIT 020 mm 0 008 in WHEEL BEARING INSPECTION Check the wheel bearing by placing the wheel on a truing stand and spinning the wheel by hand Replace the bearing with a new one if it is noisy or shows exce...

Page 111: ... 0 mm 0 08 in Axial 2 0 mm 0 08 in NOTE The COMSTAR TM WHEEL cannot be repaired and must be replaced with a new one if the service limits are exceeded DISASSEMBLY Remove the dust seal bearing and distance collar NOTE Do not forget to install the rim band when replacing the tire or tube Date of Issue July 1981 HONDA MOTOR CO LTD 109 DUST SEAL FRONT WHEEL SUSPENSION DISTANCE COLLAR OIL SEAL l 10 9 ...

Page 112: ...and distance collar in the right side of the wheel hub Wipe off the excess grease Grease on the disc will cause reduced braking efficiency and fTUlY lead to an accident Install the speedometer gearbox retainer aligning the tabs with the grooves in the hub Apply grease to the inside of the dust seal and install Apply grease to the speedometer gearbox and hub retainer Install the speedometer gearbox...

Page 113: ...e speedo meter gearbox Install the axle nut and tighten to the specified torque TORQUE 55 65 N m 5 5 6 5 kg m 40 48 ft lb Install a new cotter pin through the axle nut and axle NOTE Pump the brake lever after the front wheel is installed to ensure full braking efficiency Date of Issue July 1981 HONDA MOTOR CO LTD FRONT WHEEL SUSPENSION TAB ON LEFT FORK SPEEDOMETER GEARBOX SPEEDOMETER CABLE 111 10 ...

Page 114: ...ed Loosen the fork top and bottom pinch bolts Remove the front fork DISASSEMBLY Remove the fork bolt Remove the inner bolt NOTE Hold the fork tube in a vise with rag or soft jaws avoiding the sliding surface as shown CAUTION The inner bolt is under spring pressure Cover the inner bolt and hex wrench during removal to prevent injury caused by the bolt wrench or springflying upwards 10 12 BRAKE CALI...

Page 115: ...RING INSPECTION Measure the f ork spring free length SERVICE LIMITS 465 0 mm 18 31 in Remove the socket bolt Remove the fork tube and piston CAUTION IDo not distort the slider in a vise Date of Issue July 1981 HONDA MOTOR CO LTO FRONT WHEEL SUSPENSION M f J n V 1_ lh 6 mm HEX WRENCH L o7917 323oooo 113 10 13 ...

Page 116: ... the set ring with the snap ring pliers Remove the oil seal using the dull end of a screw driver as shown NOTE Avoid damaging the inner and outer surfaces of the fork slider when removing the set ring and oil seal SLIDER PISTON INSPECTION Check the slider for score marks scratches or abnormal wear 10 14 114 SET RING OIL SEAL SLIDER SLIDER HONDA MBS PISTON Date of Issue July 1981 HONDA MOTOR CO LTD...

Page 117: ... agent to the socket bolt threads and underside o the bolt NOTE To tighten the socket bolt it may be neces sary to install the fork spring and tighten the fork bolt provisionally Do not distort the slider in a vise TORQUE 8 12 N m 0 8 1 2 kg m 6 9 ft lb Date of Issue July 1981 HONDA MOTOR CO LTD FRONT WHEEL SUSPENSION PISTON REBOUND Jtj SPRING 115 6 mm HEX WRENCH 07917 3230000 t iftr FORK 8 BOLT I...

Page 118: ...nt of ATF SPECIFIED FLUID ATF CAPACITIES 75 cc 2 54 oz Install the fork spring NOTE Install the spring with the narrow pitch end facing up Install and torque the fork inner bolt TORQUE 34 42 N m 3 4 4 2 kg m 25 30 ft lb Install and torque the fork bolt TORQUE 60 70 N m 6 0 7 0 kg m 43 65 ft lb NOTE Hold the fork tube in a vise avoiding the sliding surface 10 16 HONDA MBS FORK SEAL DRIVER BODY FORK...

Page 119: ...e order of removal STEERING STEM REMOVAL Remove the headlight case Page 10 3 Remove the instruments Page 10 4 Remove the handlebar Page 10 5 Remove the front wheel Page 10 8 Remove the headlight case bracket Remove the steering stem nut using a 29 mm socket wrench Remove the front forks Page 10 12 Remove the fork bridge Date of Issue July 1981 HONDA MOTOR CO LTD FRONT WHEEL SUSPENSION HEADLIGHT CA...

Page 120: ... SEAL OUST WASHER Remove the ball races with the special tool NOTE If the motorcycle has been involved in an accident examine the area around the steer ing head for cracks 10 18 118 HONDA MBS BEARING ADJUSTMENT NUT TOP CONE RACE STEEL BALLS 21 TOP BALL RACE BOTTOM BALL RACE BALL RACE DRIVER 07944 1150001 or MP310 277 91774 Date of Issue July 1981 HONDA MOTOR CO LTO ...

Page 121: ... ball race steel balls and cone race Install the steering stem Install the bearing adjustment nut in the frame neck and tighten it until snug against the top cone race then back it out 1 8 turn the stem rotates freely Install the front forks Install the top bridge Tighten the stem nut TORQUE 60 90 N m 6 0 9 0 kg m 43 65 ft lb Install the removed parts in the reverse order of removal Date of Issue ...

Page 122: ...REAR WHEEL BRAKE SUSPENSION 8 12 N m 0 8 1 2 kg m 6 9 ft lb 55 65 N m 5 5 6 5 kg m 40 48 ft lb 11 0 120 HONDA MBS l Date of Issue July 1981 HONDA MOTOR CO LTD ...

Page 123: ...ber lock nut Rear shock absorber mounting bolts and nuts Swingarm pivot bolt SPECIF CATIONS ITEM Axle runout Rear wheel rim runout Radial Axial Rear brake drum I D Rear brake lining thickness Rear shock absorber spring free length Date of Issue July 1981 HONDA MOTOR CO LTD 07959 3290001 07746 0010200 07749 0010000 07746 0040200 55 65 N m 5 5 6 5 kg m 40 48 ft lb 18 25 N m 1 8 2 5 kg m 13 18 ft lb ...

Page 124: ...2 Shock absorbers improperly adjusted Hard suspension 1 Shock absorbers improperly adjusted 11 2 122 Suspension noise 1 Shock case binding 2 Loose fasteners Poor brake performance r iJ HONDA MB5 1 Brake not adjusted properly 2 Worn brake linings 3 Contaminated brake linings 4 Worn brake cam 5 Worn brake drum 6 Brake arm not properly installed 7 Worn brake shoes at cam contacting faces Date of Issu...

Page 125: ...blocks and read the axle bend The actual axle bend is 1 2 of the total indicator reading SERVICE LIMIT 0 20 mm 0 008 in REAR WHEEL BEARING PLAY INSPEC TION Check the wheel bearing play by rotating the wheel by hand Replace the bearings with new ones if they are noisy or have excessive play SERVICE LIMIT 0 027 mm 0 0010 in Date of Issue July 1981 HONDA MOTOR CO LTD REAR WHEEL BRAKE SUSPENSION ADJUS...

Page 126: ... a dial indicator gauge SERVICE LIMITS Radial 2 0 mm 0 08 in Axial 2 0 mm 0 08 in NOTE IDo not attempt to repair the spokes REAR WHEEL DISASSEMBLY Remove the dust seal bearings and dist ance collar NOTE Do not forget to install the rim band when the tire and tube are replaced 11 4 124 HONDA MBS DUST SEAL DR IVEN SPROCKET FLANGE NUT Date of Issue July 1981 HONDA MOTOR CO LTD ...

Page 127: ...g Insert the distance collar Drive in the right bearing Coat the inside of the dust seal with grease and install NOTE Drive in the bearings squarely Install the bearings with the sealed end facing outside FINAL DRIVEN SPROCKET INSTALLA TION Install the final driven sprocket with the chamfered end on the brake drum side TORQUE 55 65 N m 5 5 6 5 kg m 40 48 ft lb Date of Issue July 1981 HONDA MOTOR C...

Page 128: ...0 20 mm 3 8 3 4 in CAUTION Rotate the adjusters so that the index marks are aligned with the same scale number on both sides Torque the axle nut TORQUE 55 65 N m 5 5 6 5 kg m 40 48 ft lb Install a new cotter pin NOTE ISpread the ends of the cotter pin as shown Lubricate the drive chain Page 3 11 REAR BRAKE REAR BRAKE LINING THICKNESS Measure the brake lining thickness SERVICE LIMIT 2 0 mm 0 08 in ...

Page 129: ...ake shoes Replace the brake shoes with new ones BRAKE CAM INSPECTION Remove the brake arm Remove the indicator plate Remove the brake cam Remove the felt ring Clean the shoe contacting faces of the brake cam Date of Issue July 1981 HONDA MOTOR CO LTO BRAKE CAM BRAKE CAM 127 REAR WHEEL BRAKE SUSPENSION INDICATOR PLATE tr f FELT BRAKE ARM 11 7 ...

Page 130: ... cam with the flat on the wear indicator plate Install the brake arm NOTE Align the punch mark on the brake cam with the punch mark on the brake arm Tighten the brake arm bolt to the specified torque TORQUE 8 12 N m 0 8 1 2 kg m 6 9 ft lb Install the brake panel on the rear wheel 11 8 128 HONDA MBS BRAKE SHOE PUNCH MARKS BRAKE ARM Date of Issue July 1981 HONDA MOTOR CO LTD ...

Page 131: ...e the brake pedal Assembly of the brake pedal is essentially the reverse order of removal CAUTION Before installing the brake pedal apply grease to the sliding surface Adjust the brake pedal free play Page 3 8 Date of Issue July 1981 HONDA MOTOR CO LTD BRAKE ROD COTTER PINS BRAKE ROD e 129 REAR WHEEL BRAKE SUSPENSION BRAKELIGHT SWITCH SPRING RETURN SPRING 11 9 ...

Page 132: ...he softest position Remove the right and left rear shock absorbers DISASSEMBLY NOTE Before disassembling the shock absorbers rotate the adjuster to the softest position Remove the upper joint Q J UPPERJOINT LOCKNUT ADJUSTER v 11 10 130 r iJ HONDA MBS SHOCK COMPRESSOR REAR DAMPER Date of Issue July 1981 HONDA MOTOR CO LTD ...

Page 133: ... and left rear shock absorbers Torque the nuts and bolts TORQUE 30 40 N m 3 0 4 0 kg m 22 29 ft lb Check the operation of the shock absorbers by pressing down on the end of the frame several times by hand NOTE Install the joints with the cutout end facing inside Date of Issue July 1981 HONDA MOTOR CO LTD REAR WHEEL BRAKE SUSPENSION f 1 j L_____ ool SHOCK COMPRESSOR 131 11 11 ...

Page 134: ...and the swingarm INSPECTION Check the swingarm for cracks or damage Check the bushings for damage or other defects INSTALLATION Install the torque link on the swingarm Install the swingarm Install the rear wheel Page 11 6 11 12 SWI NGARM PIVOT BOLT SHOCK ABSORBER 132 HONDA MBS SWINGARM CHAIN CASE 18 25 N m 1 8 2 5 kg m 13 18 ft lb Date of Issue July 1981 HONDA MOTOR CO LTD ...

Page 135: ... HONDA MBS Date of Issue July 1981 HONQA MOTOR CO LTO MEMO 133 REAR WHEEL BRAKE SUSPENSIO 11 13 ...

Page 136: ...m 2 5 3 5 kg m 18 25 ft lb 4 7 N m 4 Jl kg m 2 9 5 1 It 4 HONDA MBS f 1 2 N m 0 1 0 2 kg m 0 7 1 4 ft lb 15 20 N m 1 5 2 0 kg m 11 14 ft lb 5 20N m 1 5 2 0kg m 1 14ft lb 24 30 N m 2 4 3 0 kg m 17 22 ft lb 0f j6 12 0 Date of Issue July 1981 HONDA MOTOR CO LTO 134 ...

Page 137: ... valve Brake pad pin bolts Brake caliper pin bolt Brake caliper bracket bolt Brake caliper bracket bolts SPECIFICATIONS ITEM Disc thickness Disc runout Master cylinder I D Master piston O D Caliper cylinder I D Caliper piston O D TROUBLESHOOTING Poor brake performance 1 Air bubbles in hydraulic system 2 Worn brake pads 3 Pads fouled or glazed 4 Hydraulic system leaking Date of Issue July 1981 HOND...

Page 138: ... the way back to the handlebar grip turn the bleeder valve about 1 2 rotation out then retighten NOTE Do not release the brake lever until the bleeder valve has been closed Release the brake lever gradually and wait several seconds after it reaches the end of its travel Repeat the above steps until there are no air bubbles in the fluid flowing out of the bleeder valve NOTE Keep the reservoir fille...

Page 139: ... edges of the brake disc BRAKE PAD REPLACEMENT NOTE Do not disconnect the brake hose when re placing the brake pads Straighten the tabs of the lock washer and loosen the pin bolts Remove the two caliper bolts and remove the caliper from the fork leg Date of Issue July 1981 HONDA MOTOR CO LTD HYDRAULIC BRAKE RED GROOVE PAD LOCK WASHER 137 12 3 ...

Page 140: ...out replacing another Install the shim on the back ofthe pad Ensure that the pin bolts are inserted throuth the holes in the brake pads Install the caliper on the fork leg TORQUE 24 30 N m 2 4 3 0 kg m 17 22 ft lb Tighten the pin bolts to the specified torque and bend the tabs of the lock washer against the side of each bolt TORQUE 15 20 N m 1 5 2 0 kg m 11 14ft lb BRAKE DISC INSPECTION Measure th...

Page 141: ...m the caliper DISASSEMBLY Remove the pads shims and spring by removing the pin bolts Operate the brake lever to force the piston out of the cylinder NOTE Place an oil pan under the caliper to receive brake fluid drained Avoid spilling brake fluid on painted surfaces plastic lenses or rubber parts Disconnect the brake hose from the caliper If the piston is seized in the caliper observe the followin...

Page 142: ...et Remove the sleeve Remove the pin bushing and pin boots Lift out the piston and dust seals by first pushing them into the cylinder as shown Clean the caliper grooves with brake fluid Replace the piston and dust seals with new ones INSPECTION Check the caliper cylinder for scoring scratches or other damage Measure the caliper cylinder I D SERVICE LIMIT 30 290 mm 1 1925 in 12 6 RAG PISTON SEAL DUS...

Page 143: ...ecting above the caliper Install the brake hose and seal washer TORQUE 25 35 N m 2 5 3 5 kg m 18 25 ft lb Wipe excess brake fluid off the caliper with a clean cloth Lubricate the inside of the pin boot with silicon grease and install the bushing in the caliper Apply silicon grease to the sleeve contacting face of the caliper and install the pin boot in the caliper Install the sleeve then the pin b...

Page 144: ... specified torque TORQUE 20 25 N m 2 0 2 5 kg m 14 18 ft lb Tighten the pin bolts and secure with the lock washer TORQUE 15 20 N m 1 5 2 0 kg m 11 14ft lb After the front brake has been installed bleed air from the system Page 12 2 BRAKE MASTER CYLINDER REMOVAL Drain brake fluid from the bleeder valve by operat ing the brake lever Remove the brake lever front stoplight switch rear view mirror and ...

Page 145: ...the reservoir from the master cylinder Clean the master cylinder and reservoir in brake fluid INSPECTION Check the master cylinder for score marks scratches or other defects Measure the master cylinder I D SERVICE LIMIT 12 755 mm 0 5022 in Date of Issue July 1981 HONDA MOTOR CO LTD HYDRAULIC BRAKE SNAP RING PLIERS 07914 3230001 BOOT SNAPRING MASTER PISTON 143 12 9 ...

Page 146: ... into the cylinder NOTE Replace the master piston and spring as a set Do not replace one without replacing the other Check that the snap ring is seated in the groove properly Install the front stoplight switch INSTALLATION Install the master cylinder on the handlebar TORQUE 10 14 N m 1 0 1 4 kg m 7 10 ft lb Install the brake hose and seal washer TORQUE 25 35 N m 2 5 3 5 kg m 18 25 ft lb After the ...

Page 147: ... HONDA MB5 Date of Issue July 1981 HONDA MOTOR CO LTO HYDRAULIC BRAKE MEMO 145 12 11 ...

Page 148: ... SWITCH HEADLIGHT HIGH BEAM FUSE 7A BATTERY CHARGING SYSTEM ENGINE STOP SWITCH ON 0 OFF HONDA MBS BATTERY 12V2 5 AH INSTRUMENT LIGHT IGNITION COIL i Bk R 6 J 1H Bk Y IGNITION 1 CONDENSER SCR I l I G _j CDI UNIT IGNITION SYSTEM 146 SPAR K PLUG Date of Issue July 1981 HONDA MOTOR CO LTO ...

Page 149: ...st be released before disconnecting and must be aligned when reconnecting The following color codes used are indicated throughout this section and on the wiring diagram L Blue G Green Lg Light Green R Red B Black Gr Grey 0 Orange W White Br Brown Lb Light Blue P Pink Y Yellow To isolate an electrical failure check the continuity of the electrical path through the part A continuity check can usuall...

Page 150: ...ion switch Between ignition coil and spark plug 3 Faulty ignition switch 4 Faulty ignition coil 5 Faulty COl unit 6 Faulty alternator 13 2 148 HONDA MB5 Intermittent power 1 Loose battery connection 2 Loose charging system connection 3 Loose connection or short circuit in ignition system 4 Loose connection or short circuit in lighting system Charging system failure 1 Loose broken or shorted wire o...

Page 151: ...fic gravity varies with the tem perature as shown in the accompanying table Replace the battery if sulfation is evident or if the space below the cell plates is filled with sediment The battery contains sulfuric acid A void contact with skin eyes or clothing Antidote Flush with water and get prompt medicalattention Date of Issue July 1981 HONDA MOTOR CO LTD ex u w Q en ELECTRICAL SYSTEM BATTERY HO...

Page 152: ...rolyte temperature exceeds 45 C 113 F CAUTION Quick charging should only be done in an emergency slow charging is prefe ed CAUTION Route the breather tube as shown on the battery caution label CHARGING SYSTEM PERFORMANCE TEST NOTE Be sure the battery is in good condition and fully charged before performing this test Warm up the engine Remove the frame left side cover Connect an ammeter and voltmet...

Page 153: ...e stator and flywheel as a set if not within the specifications SILICONE RECTIFIER INSPECTION Remove the seat Remove the fuel tank see page 4 9 Remove the silicone rectifier from the coupler Check for continuity with an ohmmeter The rectifier is normal if there is continuity only in the direction shown Date of Issue July 1981 HONDA MOTOR CO LTD ELECTRICAL SYSTEM WHITE YELLOW GREEN SILICONE RECTIFI...

Page 154: ...plug cap by rotating it by hand CONTINUITY TEST Measure the resistances of the primary and secon dary coils Resistances Primary coil 0 2 0 3 Ohms Secondary coil 3 4 4 2 Ohms COl UNIT REMOVAL Reme ve the fuel tank Remove the CDI unit from the coupler 13 6 PRIMARY COIL 152 HONDA MBS IGNITION COIL SECONDARY COIL CDI unit Date of Issue July 1981 HONDA MOTOR CO LTD ...

Page 155: ...st time The needle will then remain fixed unless the condenser is discharged Measuring ranges SANWA xkQ KOWA X 100Q ALTERNATOR EXCITOR COIL PULSE GENERATOR INSPECTION Warm up the engine Stop the engine Disconnect the alternator connectors Measure the exciter coil and pulse generator resist ances Black Red Green Exciter coil 50 300 Ohms Blue Yellow Green Pulse generator 10 100 Ohms Replace the stat...

Page 156: ... leads from the brakelight switch terminals Check the switch for continuity with the rear brake applied Replace the switch if necessary NEUTRAL SWITCH Disconnect the nuetral switch wire Light green Red and ground wire Green at the connector Check the switch for continuity between the wires with the transmission in neutral and with the transmission in any gear Replace the neutral switch if necessar...

Page 157: ...ADLIGHT HI LOW SWITCH HI MIDDLE LO Y to L Y toW to L YtoW TURN SIGNAL SWITCH LEFT OFF RIGHT Gr to 0 Br W to Lb W No continuity Gr to Lb Br W to 0 W HORN BUTTON B to G with button depressed No continuity with button released Date of Issue July 1981 HONDA MOTOR CO LTO HEADLIGHT HI LO SWITCH HORN BUTTON Headlight Hi Low Switch c Hi N 0 Lo Code color y Turn Signal Switch WR LEFT OFF RIGHT Code color G...

Page 158: ...n switch coupler Check continuity of terminals on the coupler in each switch position SWITCH POSITION OFF 8 W toG ON R to 8 Terminal Position IG E Eo BAT OFF ON IGNITION SWITCH REPLACEMENT Remove the instrument Push the tabs on the ignition switch and remove the switch 13 10 GREEN WIRE 156 HONDA BLACK WHITE WIRE IGNITION SWITCH INST RUMENTS MBS Date of Issue July 1981 HONDA MOTOR CO LTD ...

Page 159: ......

Page 160: ......

Page 161: ... NOT REACHING 1 No fuel in fuel tank CARBURETOR 2 Glogged fuel pipe from tank to carburetor 3 Clogged float valve in carbu retor 4 Breather hole in fuel tank cap clogged SPARKS ARE WEAK OR D0 1 Faulty spark plug NOT JUMP AT ALL 2 Fouled spark plug 3 Foulty CDI unit 4 Broken or shorted high tension cord 5 Broken or shorted ignition coil 6 Faulty ignition switch LOSS OF COMPRESSION 1 Piston rings st...

Page 162: ...maged wheel bearing 3 Wheel bearing not lubricated properly 4 Drive chain too tight TIRE PRESSURE IS TOO 1 Punctured tire LOW 2 Faulty tire valve ENGINE SPEED NOT CHANGED 1 Clutch slipping WHEN CLUTCH IS RELEASED 2 Worn clutch disc 3 Clutch disc warped ENGINE SPEED DOES NOT t 1 Carburetor choke closed INCREASE SUFFICIENTLY 2 Restricted fuel flow 3 Air cleaner clogged 4 Clogged fuel tank breather 5...

Page 163: ...rn piston rings and cylinder 2 Fuel air mixture too lean 3 Excessive carbon build up in combustion chamber 4 Ignition timing too early advanced POOR PERFORMANCE AT LOW AND IDLE SPEEDS CHECK PROBABLE CAUSE 1 Check ignition timing INCORRECT 1 Foulty COl unit 2 Foulty alternator NORMAL 2 ChJk carburetor air screw INCORRECT 1 Fuel air mixture too lean adjustment To correct screw in 2 Fuel air mixture ...

Page 164: ...D 1 Damaged fuel strainer POOR HANDLING Check tire pressure PROBABLE CAUSE 1 Steeringheavy 1 Steering cone races excessively tightened 2 Damaged steering steel balls 2 Front or rear wheel is excessively wobbling 1 Excessive play in wheel bearing 2 Distorted rim 3 Improperly installed wheel hub 4 Rear fork pivot bushing exces sively worn 5 Distorted frame 6 Improper drive chain adjust ment 3 Pulls ...

Page 165: ...NICAL FEATURE BALANCE R The motorcycle uses a single shaft primary balancer to counteract the inertia inherent induced vibration in a single cylinder 2 cycle engine Date of Issue July 1981 HONDA MOTOR CO LTD 163 15 1 ...

Page 166: ...the piston and connecting rod t INERTIA FORCE INERTIA FORCE CENTRIFUGAL FORCE ON CRANKWEIGHT TDC INERTIA FORCE ON CRANKWEIGHT BDC Inertia force created by the rotating mass is in general canceled by counterweights Their use will reduce vibration caused by the primary inertia force which occurs once every crankshaft revolution Hereinafter inertia force refers to this primary force 15 2 164 Date of ...

Page 167: ...rweight is balanced by the bal ancer Date of Issue July 1981 HONDA MOTOR CO LTO 100 100 li50 50 a 50 0 The counterweight creates a centrifugal force to neutralize one half of the inertia force The remaining inertia will be totally balanced by the balancer The centrifugal force on the counterweight neutralizes one half of the downward inertia force The balancer counteracts the remainder 165 50 50 T...

Page 168: ...r TECHNICAL FEATURES MEMO 15 4 166 HONDA MBS Date of Issue July 1981 HONDA MOTOR CO LTD ...

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