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Summary of Contents for GranTouch GT1

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Page 2: ...ssion of the requisite basic product knowledge Other information is produced by the U S distributor Yamaha International Corporation and is necessary to provide total technical coverage regarding the product The Research Engineering and Service Departments of Yamaha are continually striving to further improve all models manufactured by the company Modifications are therefore inevitable and changes...

Page 3: ...s machine or a scrambler but it is also built to EXCEL in high speed performance over the road or highways This manual is offered so that all Yamaha dealers and service engineers will become familiar with the technical information and service instructions essential to the GT1 GTMX GT 1 GTMX ...

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Page 5: ...3 WHAT IS THE TORQUE INDUCTION 12 3 1 Reed Valve construction and Handling 13 3 2 Action of Piston in the torque induction 14 CHAPTER 4 ENGINE 16 4 1 Engine Removal 16 4 2 Reed Valve 19 4 3 Cylinder Head 20 4 4 Cylinder 20 4 5 Piston Pin 22 4 6 Piston Ring 22 4 7 4 8 4 9 4 10 4 11 4 12 4 13 4 14 4 15 4 1 6 4 17 4 18 4 19 Piston 23 Crankcase Cover R H 25 Clutch 26 Primary Drive Gear 30 Kick Starter...

Page 6: ...Battery Box and Tool Box 61 Frame 61 Handlebars 61 Miscellaneous 61 CHAPTER 6 ELECTRICAL SYSTEM 62 6 1 6 2 6 3 6 4 6 5 6 6 6 7 6 8 6 9 6 10 6 11 6 12 Description 62 Table of Component Parts 62 Connection Diagram 62 Ignition System Function and Service 63 Ignition Timing 63 Ignition Coil 63 Condenser 63 Charging System 64 Battery 65 Checking the Main Switch removed from the chassis 66 Spark Plug 66...

Page 7: ...l I I Profile GTI CHAPTER I GENERAL Right hand side Left hand side 1 GENERAL Profile ...

Page 8: ...GENERAL Profile GTMX Right hand side Left hand side 2 ...

Page 9: ...ider The GT1 GTMX is equipped with a magneto To start the engine kick the kick pedal 4 Powerful Brakes Patented waterproof dustproof brake drums provide safe fade free braking on wet or dusty roads 5 Front Fork Design The Yamaha GT1 GTMX employs a front fork design well known for its strength and superior handling characteristics Its use assures the rider of the ultimate suspension for even the ro...

Page 10: ...2 mph 7 5rn at 35 km h 7 5m at 35 km h Engine Model 393 367 Type 2 stroke gasoline 2 stroke gasoline Lubricating system Separate lubrication Separate lubrication YAMAHA Autolube YAMAHA Autolube Cylinder Single forward inclined Single forward inclined 5 port piston valve 5 port piston valve Displacement 4 39 cu in 4 39 cu in Bore and stroke 1 850 X 1 654 in 1 850 X 1 654 in Compression ratio 6 8 1 ...

Page 11: ...ring oil damper Cushion system rear Coil spring oil damper Coil spring oil damper Steering system Caster 63 30 63 30 Trail 2 7 in 68 mm 2 7 in 168 rnm Braking system Type of brake Interna expansion Interna expansion Operation system front Right hand operation Right hand operation Operation system rear Right foot operation Right foot operation Tire size Front 2 50 15 4PR 2 50 15 4PR Rear 2 75 14 4P...

Page 12: ... f i f TI _ I X Ol 8 I I 3 I I I I I I I I I I I I I 7 s e e 5 I f I 0 I II I I t I I 1 __ 1 I Ill 4 3 2 1 1 I1 tance on evel road Runnins 1es1s ii 10 20 30 40 50 Vehicle speed m p h The following tools and instruments are required to service the GT1 GTMX 1 General Tools 1 Plug wrench 23 x 29 mm 2 A set of wrenches 3 A set of socket wrenches 4 Plastic tip hammer 5 Steel hammer 6 Circlip pliers ST ...

Page 13: ...ctro tester tachometer engine rpm meter hydrometer etc will be furnished 3 Other Materials _1 2 3 1 Grease I I 2 Gear oil 3 Auto lube oil 5 4 Overhauling stand Wooden box 5 Wiping material 6 Parts tray 8 7 oil jug 8 oiler 9 9 Yamaha Bond No 5 10 10 Yamaha Bond No 4 6 Fig 1 5 3 The use of a wooden box as shown in the above photo will facilitate engine service and overhaul Consumable parts such as g...

Page 14: ...erator grip The oil pump automatically regulates the volume of lubricating oil according to engine speed and throttle valve opening thus pumping the precise amount of oil for engine lubrication under any operating condition This automatic separate lubrication does not merely eliminate disadvantages in the conventional pre mix system but it further improves the performance and efficiency of two str...

Page 15: ...ing a Fully close the accelerator grip b Turn the oil pump starter plate in the direction of the arrow marked on the plate Then measure the gap between the adjusting pulley and the adjusting plate Keep the gap as wide as possible by observing it with the eye Fig 2 3 1 Fig 2 3 2 9 c Insert a feeler gauge 0 15 mm into the gap When the gap allows it to enter Stroke is correct When the gap does not al...

Page 16: ...g 2 3 6 below will be between 0 5 to 1 0 mm 0 02 0 04 in A Handle grip Fig 2 3 6 Check the play of the throttle cable A by pulling the outer part of the throttle grip If th8 play is excessive or insufficient adjust the play with the adjusment screw 10 2 Autolube Cable Adjustment a Adjust the pump cable so that the marking arrow on the Autolube pump adjusting pulley is aligned with the guide pin se...

Page 17: ...f oil bleed the pump in the following manner 11 Remove the bleeder bolt Fig 2 3 9 11 2 YAMAHA AUTOLUBE Bleeding Next rotate the starter plate in the direction of the arrow marked on the plate Continue turning the plate until no air comes out with the oil and tighten the bleeder bolt To facilitate this bleed ing fully open the accelerator grip and rotate the starter plate As the plunger stroke beco...

Page 18: ...engine it is the most important to meet these requirement satisfactorily As a measure to transfer a sufficient amount of fuel air mixture to the cy inder and to force the burned gases completely out of the cylinder the 5 port system has been in use However Yamaha has invented a new torque induction engine to achieve the following improvements advanced inlet port timing elimination ot any possible ...

Page 19: ...ndled with special care a Storage The reed valve must be stored in a clean and dry place and must not be exposed to the sun Particularly it must be kept free from salt Avoid allowing your hand to touch the valve b Inspection al Valve Check the valve for cracks and breakage bl Valve Stopper The valve stopper limits the movement of the reed valve cl Set screw The valve and valve stopper should be fa...

Page 20: ...ve to open and fuel air mixture streams into crankcase 2 Piston Closes Exhaust Port and Moves Up to T D C Fuel air mixture transferred into cylinder through main auxiliary transfer and 5th port is compressed by piston ignited just B T D C and burned Piston skirt clears inlet port fuel air mixture streams into crankcase through piston inlet port and cylinder inlet port 3 Piston Moves Down from T D ...

Page 21: ...inder As a result crankcase pressure decreases e Scavenging by the 5th Port On the 5 port cylinder the auxiliary transfer ports are positioned on the same level as the main transfer ports As the piston lowers to the position as illustrated the fuel air mixture in the cylinder is compressed and is going to steam into the cylinder through the main and auxiliary transfer ports On the torque induction...

Page 22: ...vent any harmful foreign material from entering the interior of the engine assembly 2 Before engine removal and disassembly be sure 3 you have proper tools and deaning equipment so you can perform a clean and efficient job During disassembly of the engine clean all parts and place them in trays in order of disassembly This will make assembly time faster and easier and insure correct installation o...

Page 23: ...eel magneto will break loose Fig 4 1 7 17 6 7 c ENGINE Engine Removal Remove the two screws holding the flywheel magneto base to the crankcase and remove the flywheel base Fig 4 1 8 Remove the woodruff key It is advisable to place the woodruff key on the flywheel magneto using its magnetic force which the key is removed for engine service Fig 4 1 9 Disconnect the master link and remove the chain F...

Page 24: ...n up and down at the center of the lower section with the rear wheel on the ground 8 Remove the pump cover and pump cable Fig 4 1 12 9 Loosen the carburetor band Fig 4 1 13 18 10 Disconnect the oil line and be sure to plug the hole to prevent oil from flowing out Fig 4 1 14 11 Disconnect the fuel line at the bottom of the fuel tank Fig 4 1 15 12 Remove the throttle valve Fig 4 I 16 ...

Page 25: ... 1 17 Fig 4 1 20 14 Remove the engine mounting bolts rear 4 2 Reed Valve The reed valvf located between cylinder and Co 11_1 retor A Removing the reed valve 1 Remove the carburetor Fig 4 I I 8 15 Remove the engine mounting bolts front Fig 4 2 1 2 Remove the oil delivery line Fig 4 1 19 Fig 4 2 2 19 ...

Page 26: ...hould be loosened and tightened in a cross pattern and in progressive stages Fig 4 3 1 Fig 4 3 2 B Removing Carbon Deposits Carbon deposits on the cylinder head combustion chamber and top of the piston will result in an increase in the compression ratio as well as preignition and engine overheating ScraPe the cylinder head and piston dome clean Fig 4 3 3 4 4 Cylinder The Yamaha GT1 GTMX engine emp...

Page 27: ...sizes 2 The cylinder should be rebored and honed to the diameter of the oversize piston plus the minimum allowable clearance 4 4 B 2 3 The error between the maximum and minimum diameters after honing should be no more than 0 04 mm 0 0015 4 If cylinde r rebore is necessary be sure to cham fer all port edges to prevent the rings from catching breaking on a sharp port edge D Removing Carbon Deposits ...

Page 28: ...to Piston Pin Fit The piston pin should fit snugly in its bore so that it drags a little as you turn it If the piston pin is loose replace the pin and or the piston lf the pin has step wear in its center replace the needle bearing as well as the piston pin Check the small end of the connecting rod for wear by inserting the piston pin and bearing Fig 4 5 2 22 Fig 4 5 3 4 6 Piston Ring A Removing th...

Page 29: ... 35 mm 0 006 0 014 for both No 1 and No 2 rings Removing carbon Carbon on the piston rings and in the ring grooves will make the rings stick in the piston thus causing gas blow by Remove the rings from the piSton and clean the carbon from the rings and ring grooves 4 7 Piston The piston is made of a high slilicon aluminum alloy A Checking and Correcting the Piston to Cylinder Wall Clearance 1I Mea...

Page 30: ...area Lightly sand the seizure high spot on the piston with oil store or 400 sandpaper until smooth Fig 4 7 2 Removing carbon Remove carbon accumulations on the piston crown using a screwdriver or a sawblade Fig 4 7 3 24 Carbon and gum accumulations in the ring groove will result in piston ring seizure Re move them from the ring groove Fig 4 7 4 B Piston Installation Direction Instal the piston wit...

Page 31: ...crankcase cover gasket Replace it if damaged Fig 4 8 3 8 Installation Spread YAMAHA Bond No 5 over the mating surface of the crankcase R Place the crankcase cover gasket on the crankcase and apply Yamaha Bond No 5 and replace the crankcase cover R Be sure to aprilv YAMAHA Bond No 5 to the mating surface other wise the oil will leak Note When installing the crankcase cover R make sure that the pump...

Page 32: ...r engaged A shock absorber consisting of rubbers is between the primary driven gear and the clutch housing The primary drive gear has 19 teeth and the primary driven gear 68 teeth Primary reduction ratio 68 19 3 578 I Driven gear comp 2 0 ring 3 Thrust plate 4 Thrust plate 5 Clutch boss 6 Cushion ring 7 Friction plate 5 8 Clutch plate 9 Pressure plate 10 Bolt 11 Clutch spring 12 Clutch boss washer...

Page 33: ...the clutch boss 3 Loosen the lock nut and then remove the clutch ass y 27 ENGINE clutch Fig 4 9 4 C Checking the Clutch Spring If the free length of the spring is 1 mm 0 04 in or shorter than the standard free length replace it Free length 31 5 mm 1 24 in 31 5 Fig 4 9 5 Fig 4 9 6 D Checking the Friction Plates Inspect the friction plates for wear Replace them if they show 3 5 mm 0 138 in or more w...

Page 34: ...r because it will cause excessive noise If any scratches are found replace the spacer to avoid impaired clutch action Fig 4 9 9 28 F Checking the Primary Gear Retaining Co liar Spacer Place the primary gear retaining collar around the main axle and again check it for radial play If play exists replace the gear retaining collar Replace any collar with step wear on its outer surface Fig 4 9 10 G Fit...

Page 35: ...bearings If these washers and bearings are incorrectly installed the clutch boss will rub directly on the driven gear impairing clutch action The thrust bearing assembly fits on the primary retaining collar but it may slip out of place when installing clutch boss Therefore apply grease to both surfaces of the bearing to make it stick to the gear retaining collar Before installing the clutch plate ...

Page 36: ... the lock nut Fig 4 9 15 2 Adjusting the Clutch Cable Tension The clutch cable becomes slackened after being used for a long time Occasionally the cable must be adjusted so that the play at the clutch lever is frbm 2 to 3 mm 1 16 1 8 in Fig 4 9 16 30 4 1 0 Primary Drive Gear A Removal Feed a roll up rag between the teeth of the primary drive gear and the primary driven gear to lock them and loosen...

Page 37: ...That is the kick gear meshes with idler gear only when the kick starter pedal is kicked After the engine has started the kick gear and the idler gear disengage This mechanism not only eliminates noise resulting from the constant mesh of the kick gear with the idler gear but also greatly contributes to the durability of the kick starter assembly Kick gear Kick pinion gear Kick idler gear Thrust was...

Page 38: ...seal 10 Circlip 11 Kick spring cover 12 Kick spring 13 Kick spring guide 14 Circlip 15 Shim 16 Kick gear 17 Kick clip 18 Kick spring stopper A Removing the Kick Idler Gear B Removal Remove the circlip with clip pliers Then the kick idler gear can be easily removed Fig 4 11 3 Fig 4 11 4 1 2 32 Remove the kick spring Fig 4 11 5 Then remove the kick starter assembly Fig 4 11 6 ...

Page 39: ...t 4 Gear shift 5 Shift drum 6 Shift fork ENAINE Shift Mechanism gear shift drum When the change pedal is moved the unit iS designed to shift through five stages Neutral Low Second Third and Top throughout one complete turn of the gear shift drum The stopper plate holds the gear shift drum pin so that gear shifting can be correctly positioned at each gear position The gear shiftdrum is provided wit...

Page 40: ...ft return spring will impair the return action of the shifting mechanism f ti 0 jf71 Fig_ 4 12 4 34 C Adjusting the gear shift arm Adjusting or correcting the travel of the gear shift arm to prevent improper shifting progression excess feed or insufficient feed of the gear shift arm is accomplished by turning the gear shift return spring stop screw eccentric bolt in or out Pin 0 0 Gear shift arm A...

Page 41: ...ch with a hammer and the shock will loosen the nut Fig 4 13 2 B Inspection A worn drive sprocket will result in excessive chain noise and shorten the life of the chain Check the sprocket for worn teeth and replace if they are worn Worn Bent 1eeth Wear area Good Fig 4 13 3 35 ENGINE Drive Sprocker Crankcase 4 14 Crankcase A Separating 1 Remove the change shift drum stopper ever and stopper spring F...

Page 42: ...ote Fully tighten the bolts of the crankcase dividing tool keeping the tool in a hori zontal position The crankcase is designed to split into twp halves right and left Only one drain plug is provided for both the transmission and clutch housings Both housings can be drained at the same time by removing the drain plug B Reassembling When reassembling the crankcase be sure to apply YAMAHA BOND No 4 ...

Page 43: ...ig 4 15 1 and 2 The primary reduction ratio is 68 19 3 578 Therefore the total reduction ratios will be Primary reduction ratio x Transmi ion gear reduc tion x Secondary reductiofl ratio Total reduction ratio Primary Reduction Ratio 68 19 3 578 Secondary Reduction Ratio 41 14 2 928 Transmission Gear Total Reduction Ratio Reduction Ratio 1st 39 12 3 250 34 064 2nd 34 17 2 000 20 962 3rd 30 21 1 429...

Page 44: ...Drive axle ll Collar 2 2nd wheel gear 1 I shim 13 Drive axe 14 Clip ar 15 3rd wheel ge h I gear 16 4th w ee 17 1st wheel gear 18 Shim 19 Circlip her 20 Thrust was 21 Wave washer K k idler gear 22 ic h ft washer 23 Change s a 24 Circli_P SOS 25 Bearrn i o 25 40 5 26 Oil sea 27 Distance collarl k t whee 28 Spree e 29 Lock washer 30 Lock nut seal d 011 31 Push ro Fig 4 15 2 38 ...

Page 45: ... drive shaft end with a plastic tip hammer Fig 4 15 4 39 ENGINE Transmission Assembly 3 Pull out the shift drum assembly Fig 4 15 5 B Reinstallation Reinstall the transmission and shifter as a unit in the left crankcase half after they are sub assembled They cannot be installed separately The trans mission unit must be in neutral during installation Fig 4 15 6 ...

Page 46: ...e parts The crankshaft is also more susceptible to wear and therefore it must be handled with special care Crank L H SD 20 35 7 2 38 Fig 4 16 1 3 Fig 4 16 2 40 Cylinder head Piston Piston ring set pin clip Cylinder body Connecting rod Crank pin Distance collar Crank R H 1 Crank L H 2 Crank R H 3 Connecting rod 4 Bearing 5 Crank pin 5 ...

Page 47: ...t small end to determine the 2mm 0 078 in disassemble the crank shaft check amount of wear of crank pin connecting rod crank pin and large and bearing at large end end bearing Replace defective Fig 4 16 5 parts Sma I end play after reassem bly should be witt in 0 8 1 0 mm 0 031 0 04 in Check the connecting rod for Move the connecting rod to one If excessive side play is present side play at large ...

Page 48: ...ved or installed if the cases are first heated to approximately 200 400 F However cold removal and installation may be done satisfactorily 1 Removal a Pry the oil seals out of plrtce wi h a slot head screwdriver Always replace the oil seals when overhauling the engine Note Place a piece of wood und r the screwdriver to prevent damage to the case 42 SD 25 40 5 Fig 4 17 2 ...

Page 49: ...n starter jet The carburetor floats have been specially designed to keep the float leve from fluctuating due to vibration or shock 1 Pilot jet 2 Main nozzle 3 Main jet 4 Valve seat ass y 5 Valve seat washer 6 Float 7 Float pin 8 Gasket 9 Float chamber body 10 Spring washer 11 Pan head screw 12 Body fitting screw 13 Pilot adjusting spring 14 Pilot adjusting screw 15 Air adjusting spring 16 Air adju...

Page 50: ... check the carburetor as de scribed in 1 and 2 above If neither 1 nor 2 cures the overflowing it may be caused by dirt or dust in the fuel preventing the float valve from seating properly If any dirt or dust is found clean the carburetor petcock lnr n qc tank Valve seat LFloat valve Fig 4 18 2 Fuel Dust Fig 4 18 3 44 4 Cleaning the carburetor Dis ssemble the carburetor and wash all its parts in a ...

Page 51: ...dent mark 367El 367El 4 19 Air Cleaner B Cleaning A Removal To remove the air cleaner ass y first remove the oil tank and then remove the air cleaner cap fitting bolt element can be pulled out from the case Fig 4 19 1 Fig 4 19 2 45 Wash the foam filter thoroughly in solvent until all dirt has been removed Squeeze all the solvent out Pour oi onto the filter any grade of 20 or 30 wt work it complete...

Page 52: ...e an unexcelled competition machine 5 1 Front Wheel The 15 front wheel is equipped standard with a 2 50 15 Trials Universal tire I Hub 2 Spoke set 3 Rim 4 Tire 5 Tube 6 Rim band 2 7 Bearing spacer 8 Spacer flange 9 Bearing 10 Oil seal 11 Circlip 12 Thrust washer 2 13 Meter clutch 14 Drive gear 15 Brake shoe plate 16 Cam shaft 17 Oil seal 18 Brake shoe comp 19 Return spring 20 Cam shaft I ever 21 B...

Page 53: ...ide a seal against dust and water A Removal 1 Disconnect the brake cable at the front brake lever Fig 5 1 2 2 Disconnect both the brake cable and speedo meter cable from the front brake shoe plate Fig 5 1 3 3 Remove the cotter pin Fig 5 1 4 47 CHASSIS Front Wheel 4 Remove the front wheel nut Fig 5 1 5 5 Loosen the front wheel axle lock bolt Fig 5 1 6 6 Remove the front wheel axle by simultaneously...

Page 54: ...ig 5 1 9 2 3 48 Brake shoe Measure the outside diameter at the brake shoe with slide calipers If it measures less than 106 mm 4 17 in I replace it Smooth out a rough shoe surface with sandpaper or with a file Fig 5 1 10 Brake drum Oil or scratches on the inner surface of the brake drum will impair braking performance or result in abnormal noises Remove oil by wiping with a rag soaked in lacquer th...

Page 55: ...lace it 11 Check the lips of the seals for damage or warpage Replace if necessary 49 CHASSIS Front Wheel Replacing the Wheel Bearing a First clean the outside of the wheel hub b Insert the bent end of the special tool as shown in Fig 5 1 14 into the hole located in the center of the bearing spacer and drive the spacer out from the hub by tapping the other end of the special tool with a hammer Both...

Page 56: ...n the frame It is also wide enough to protect the engine unit from dust and water 1 Hub 2 Bearing spacer 3 Bearing 4 Oil seal 5 Spacer flange 6 Brake shoe plate 7 Oil seal 8 Brake shoe comp 9 Return Spring 10 Cam shaft 11 Cam shaft lever 12 Bolt 13 Nut 14 Spring washer 15 Plain washer 16 Tension bar 17 Tension bar bolt 18 Spring washer 19 Nut 20 Cotter pin 2 I Plain washer 22 Cotter pin 23 Wheel s...

Page 57: ...and brake rod from the rear shoe plate 3 4 CHASSIS Rear Wheel Loosen the chain tension adjusting nuts and bolts on both right and left sides Fig 5 2 5 Remove the cotter pin and then remove the rear wheel shaft nut Fig 5 2 3 Fig 5 2 6 Fig 5 2 4 51 5 Pull out the rear wheel shaft by striking it with a plastic tip hammer Fig 5 2 7 ...

Page 58: ...th the levers It is noted that to remove the inner tube one side of the tire should be pried out of the wheel rim Installation a Insert the tube between the tire and the wheel rim and inflate the tube Be sure that the valve stem is directed toward the wheel shaft At this time the tire is still halfway off the rim b C d Force the tire completely back on the wheel rim by the use of tire levers For t...

Page 59: ...the tire or the pattern is worn out replace the tire If the lip of the oil seal is damaged or warped replace it 5 3 Rear Sprocket Checking and Adjustment The rear wheel sprocket is installed on the rear wheel hub To replace the sprocket take the following steps 1 Removing the sprocket a Bend the lock washer ears flat Fig 5 3 1 b 2 53 CHASSIS Rear Wheel Rear Sprocket Remove the sprocket mounting bo...

Page 60: ...ent riding com fort along Vr ith handling superiority The maxi mum stroke travel is almost 75 mrn 3 0 inches The combination of fork stability and long stroke travel provides safety and handling ease for the rider over even the roughest terrain This front fork design also reduces weight eases maintenance and gives functional and attractive appearance The simplicity and dependability of the front f...

Page 61: ...ng the Inner and Outer Tubes 1 Drain the oil from the fork 2 Fig 5 5 5 Place a rubber sheet or tire tube around the outer tube nut and wind a rope or outer tube nut wrench and turn it counterclockwise then remove the nut The inner tube can be sepa rated from the outer Fig 5 5 6 ...

Page 62: ...3 12 if I I 10 0 3 2 Fig 5 5 7 Front Exploded View 56 I 2 3 4 5 6 7 8 9 10 11 12 13 Outer tube 0 ring Fork spring Spring upper washer Spacer Inner tube Side metal Outer nut comp Oil seal Dust seal Packing Cap washer Cap bolt ...

Page 63: ...ront fork on the frame a Bring up the front fork to the correct posi tion and tighten the under bracket mounting bolt Fig 5 5 8 b Pour oil into the inner tube through the upper end opening Front fork oil Motor oil l0W 30 Right Left 97 cc 3 3 fl oz 120 cc 4 1 fl oz c Install the cap bolt then tighten the lower and upper pinch bolts 57 CHASSIS Front Fqrks Grear Shocks 5 6 Rear Shocks The rear shocks...

Page 64: ... frame A Removing 1 Set the fuel petcock lever at the Stop posi tion and disconnect the fuel line at the petcock Fig 5 7 1 2 Open lie seat Fig 5 7 2 3 Remove the gas tank Fig 5 7 3 5 8 Rear Swing Arm 58 The rear swing arm is made of steel tube that improves the strength and torsional rigidity A Removing 1I Remove the chain case mounting screws Fig 5 8 1 ...

Page 65: ...he bushing as indicated in Fig 5 8 4 and check it for play If the play is excessive replace the bushing Fig 5 8 4 Grease the rear arm shaft periodically Replacing Rear Swing Arm Bushings On motorcycles being used only for on the street riding rear swing arm bushings should be replaced every 10 000 km 6 000 miles The same may not apply to those used for racing or rough riding Replacement should be ...

Page 66: ...of the machine Replace any ball race having scratches or streaks resulting from wear Clean and grease the balls and races periodically Note Do not use a combination of new balls and used races or vice versa If any of these are found defective replace the whole ball and race assembly 60 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Ball race 2 Ball race 1 Ball Ball race cover Handle crown Hand...

Page 67: ...e double cradle type frame is made of high tension steel tubes that provide strength rigidity and light weight Other dimensional features include high ground clearance narrow width and long wheelbase The engine is bolted to the frame at three positions 61 5 1 2 Handlebars The upswept type longer handlebars are ideal for motor cross events and are provided with deep cut pattern grips to prevent han...

Page 68: ... 15 15W Headlight Koito Mfg Flasher pilot light 6V 3W Speedometer Nippon Seiki Handlbar switch Asahi Denso Ignition coil Hitachi Ltd CM 61 20N Horn Nikko Kin oku GF 6 Battery Nippon Battery 6N4A 4D Rectifier Mitsubishi E ec OSI H2M 8 Fuse Taiko Mfg 10A Stop switch Asahi Deonso Taillight Koito Mfg 6V 25W 5 3W 6 3 Connection Diagram Condenser Contact breaker Rectifier Fu e Meter light GTI Fig 6 3 1 ...

Page 69: ... D C Maximum ignition point gap 0 3 to 0 4 mm 0 012 0 015 6 6 Ignition Coil Primary coil resistance value 1 7 1 10 I2o c or 68 FJ Secondary coil resistance value 6K 1 10 20 C or 68 Fl For measuring methods refer to Fig 6 6 1 63 o u E ill 1 I i Ignition coil JS l_ I W 2 Se t the tester on the Resistance position Fig 6 6 1 Spark Test Remove the spark plug from the cylinder head and reconnect the hig...

Page 70: ...t 8 000 rpm The charging and lighting capacity is obtained when the battery is fully charged If the battery is in a low state of charge and low in voltage the charging rate will not be exactly the same as above However it is desirable that the figures are as close as possible Silicon rectifier SW White o 0 Red Red Flywheel magneto Fig 6 8 1 64 2 Silicon Rectifier The alternating current which is g...

Page 71: ...eplaced 2 lf the bottoms of the ce ls are filled with corrosive material falling off plates the battery should be replaced 3 11 the b lttery shows the following defer ts 1t should be replaced O The voltage will not rise to a specific va 11e even after long hours charging O No gassing occurs in any cell ELECTRICAL SYSTEM charging System Battery GTl 65 o The 6V battery requires a charging voltage of...

Page 72: ...nearly o Q and no short circuit is noticed between the terminals as well as between the lead terminal and the switch body the main switch is in good condition 6 11 Spark Plug The life of a plug and its discoloring vary according to the habits of the rider At each periodic inspection replace burned or fouled plugs with suitable ones deter mined by the color and condition of the bad plugs One machin...

Page 73: ...nal systems consist of the horn and stoplight power source battery and the headlight taillight meter lamps speedometer 1 Headlight The headlight has two 6V 15W bulbs A beam directing adjusting screw is fitted on the right side of the light rim so that the horizontal direction of the beam can be adjusted not vertically t Taillight and Stoplight A 6V 5 3W taillight and a 6V 17W stoplight are mounted...

Page 74: ... 3 785 Liters 1 2 Imperial gals 4 537 Liters 1 014bhp 0 9859 ps 7 235 ft lb GAS 12 1 0 33 10 7 1 66 53 5 FUEL 16 1 0 25 8 0 1 25 40 0 LENGTHS Multiply Kikometers km Miles mi Meters Im I Feet ft WEIGHTS Grams g Ounces oz VOLUMES Imperial gallons Liters I Q Quarts qt Cubic centimeters cc Fluid ounces fl 07 OTHERS TO Foot pounds ft lb Kilometers per liter km Q Miles per gallon mpg OIL RATIO CHART 20 ...

Page 75: ...sher light 6Vl7 High beam Jldic Meter light 6V3W _J SJ fofl p M i t A _AA4j W k t 7 f i Q z g c 4 L GT_1 Circuit Diagram u flasher light switch I I I I I I II SIiicon rectifier L tJ Rear flasher light R 6V 17Yf 1 I ...

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