Yamaha YTZ250S 1986 Service Manual Download

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Summary of Contents for YTZ250S 1986

Page 1: ...INDEX GENERAL INFORMATION REGULAR MAINTENANCE AND ADJUSTMENTS ENGINE MAINTENANCE AND REPAIR CHASSIS MAINTENANCE AND REPAIR ELECTRICAL TROUBLESHOOTING APPENDICES ...

Page 2: ...ve Clothing 1 7 Be Careful where You Ride 1 8 Modification 1 8 RIDING YOUR TRI MOTO 1 9 Getting to Know Your Tri Moto 1 9 Learning to Ride Your Tri Moto 1 9 Turning Your Tri Moto 1 10 Climbing Uphill 1 11 Riding Downhill 1 12 Crossing a Slope _ 1 12 Crossing through Shallow Water 1 13 Riding over Rough Terrain 1 13 Sliding and Skidding 1 13 What to Do If 1 14 PREOPERATION CHECKS 1 15 STARTING AND ...

Page 3: ... of the model you own 2 If your machine is stolen the authorities will need the number to search for and identify your machine Vehicle Identification Number Engine Serial Number The engine serial number is stamped into the elevated part of the right rear section of the engine The vehicle identification number is stamped on the right of the steering head pipe II 1 Engine serial number 1 Vehicle ide...

Page 4: ...op switch Light Dimmer switch 1 2 Fuel tank cap 1 Marks NOTE The design and specification of the machine you have purchased may partly differ from those shown in the photos this manual carries Align cap and lever marks correctly If misaligned press again ...

Page 5: ...uel will not flow Always return the lever to this position when the engine is not running ON With the lever in this position fuel flows to the carburetor Normal riding is done with the lever in this position HI OFF 1 3 Starter knob 0 10 20 300O C Q 30 50 70 90 of CD 1 2 o i Reserve fuel cock RES This indicates RESERVE If you run out of fuel while riding move the lever to this position THEN FILL TH...

Page 6: ... T T S but same quality as A545 Never mix two types of oil in the same batch clotting of the oil could result Transmission Oil Recommended oil SAE 10W30 SE Transmission oil capacity Periodic oil change 1000 cm3 0 88 Imp qt 1 06 US qt Overhaul 1050 cm3 0 92 Imp qt 11 0 US qt 1 4 1 Drain plug 1 Filler plug CHECKING OIL LEVEL On the right side of the engine there is a checking screw To check warm up ...

Page 7: ...t level in the radiator tank when the engine is cold If the coolant level is low add the coolant 1 Radiator cap 1 5 1 Coolant level 2 To recovery tank 3 Check the coolant level in the recovery tank when the engine is cold If the coolant level is below the LOW level add the coolant upto FULL level Recommended coolant High quality ethylene glycol antifreeze containing corrosion inhibitors for alumin...

Page 8: ...or up to the specified level 2 After starting the engine race the engine a few times and add the coolant again up to the specified level 3 When the coolant level becomes stable stop the engine and tighten the radiator cap 1 6 SAFETY INFORMATION When you ride your machine you must know and use the following for your safety Ride with Care and Good Judgement 1 Speed limiter For beginning riders this ...

Page 9: ...is and jumping You may lose control of the machine or overturn 8 Use extra caution when riding the machine with additional loads such as ac cessories cargo or a trailer The machine s handling may be adversaly af fected Reduce your speed when adding additional loads 9 When transporting the machine in another vehicle be sure it is kept upright and that the fuel cock is turned to the OFF position If ...

Page 10: ... may encounter hidden obstacles which could cause an accident 3 Do not ride in areas posted no trespass ing Do not ride on private propertly without getting permission 4 When riding in an area where you might not easily be seen such as desert terrain mount a caution flag on the machine Do NOT use the flag pole bracket as a trailer hitch Modifications 1 This machine is designed to conform with laws...

Page 11: ...eels and may possibly suffer injury 1 9 Select a large flat area off road to become familiar with your Tri Moto Make sure that this area is free of obstacles and other riders You should practice control of the throttle brakes shifting procedures and turning techniques in this area before trying more difficult terrain Avoid riding on paved surfaces the Tri Moto is designed for off road use only and...

Page 12: ...t your weight on the foot peg to the outside of the turn opposite your desired direction and lean your upper body into the turn Use the throttle to maintain an even spped through the turn This maneuver will let the wheel on the inside of the turn slip slightly allowing the Tri Moto to make the turn properlY Lean towards inside of turn This procedure should be practiced at slow spped many times in ...

Page 13: ...to tipping over backwards 1 11 If you are climbing a hiil and you find that you have not properly judged your ability to make it to the top you should turn the Tri Moto around while you still have forward motion provided you have the room to do so and go down the hill WARNING DO NOT attempt turning around on a hill unless you have mastered the turning technique on flat ground If your Tri Moto has ...

Page 14: ...i Moto requires you to preperly position your weight to maintain proper balance Be sure that you have learned the basic riding skills on flat ground before attempting to cross a sloping surface Avoid slopes with slippery surfaces or rough terrain that may upset your balance As you travel across a slope lean your body in the uphill direction It may be necessary to correct the steering when riding o...

Page 15: ...in should be done with caution Look out for obstacles which could cause damage to the Tri Moto or could lead to an upset or accident Be sure to keep your feet firmly mounted on the footrests at all times Avoid jumping the Tri Moto as loss of control and damage to the Tri Moto may result WARNING Use extreme caution when crossing sharp bumps Crossing at too great a speed could cause the Tri Moto to ...

Page 16: ...f necessary gradually let off on the throt tle and or steer to the outside of the turn see pages 1 10 and 1 11 If your Tri Moto starts to slide sideways Steer in the direction of the slide if you have the room Applying the brakes or accelerating is not recommended until you have corrected the slide see pages 1 13 and 1 14 If your Tri Moto can t make it up a hill you are trying to climb Turn the Tr...

Page 17: ...excessive wear Steering Check that the handlebars can be turned smoothly and have no excessive play 1 15 Front forks and rear shock Check that they operate smoothly and there is no oil leakage Cables Wires Check that the clutch brake and throttle cables move smoothly Check that they are not caught when the handlebars are turned or when the front forks travel up and down Muffler Check that the muff...

Page 18: ...l the fuel tank with a break in oil fuel mixture of 12 1 to 14 1 2 Perform the preoperation checks on the machine 3 Start and warm up the engine Check the idle speed and check the operation of the controls and the engine stop switch 4 Operate the machine in the lower gears at moderate throttle openings for five to eight minutes Stop and check the spark plug condition it will show a rich condi tion...

Page 19: ...easer to it with a paint brush Do not apply degreaser to the chain sprockets or wheel axles 3 Rinse the dirt and degreaser off with a garden hose use only enough pressure to do the job Excessive hose pressure can force water into wheel bearings front fork seals and transmission seals Avoid using high pressure hoses such as those found in coin operate car washes 4 After the majority of the dirt has...

Page 20: ... several times to coat the cylinder walls with oil 3 Remove the drive chain clean it thoroughly with solvent and lubricate it Reinstall the chain or store it in a plastic bag tied to the frame 4 Lubricate all control cables 5 Block the frame up to raise the wheels of the ground 6 Tie a plastic bag over the exhaust pipe outlet to prevent moisture from entering 7 If the machine is to be stored in a ...

Page 21: ...1 19 ...

Page 22: ...Air Filter 2 8 Clutch 2 10 Front Brake Adjustment 2 10 Rear Brake Pedal Height Adjustment 2 10 Checking the Front and Rear Brake Pads 2 11 Inspecting the Brake Fluid Level 2 11 Drive Chain Slack Check 2 11 Drive Chain Slack Adjustment 2 12 Drive Chain Cleaning and Lubrication 2 12 Steering Head Adjustment 2 12 Wheel Bearings 2 13 Fuel Cock 2 14 Tires 2 14 Cable Inspection and Lubrication 2 15 Brak...

Page 23: ...arks in race on days year quired PISTON Inspect crack Inspect and clean Replace Remove carbon PISTON RINGS Inspect Check ring end gap Replace PISTON PIN SMALL END BEARING Inspect Replace CYLINDER HEAD Inspect and clean Remove carbon Retighten CYLINDER seizure Inspect and clean Replace wear Y E I S Inspect AIR FILTER Use Foam Clean and oil air filter oil Replace CLUTCH Inspect friction plate Inspec...

Page 24: ...t bearings Replace bearings Lubricate THROTTLE CONTROL CABLE Check routing and connection Lubricate NOTE _______________________ Brake fluid replacement 1 When disassembling the master cylinder or caliper cylinder replace the brake fluid Normally check the brake fluid level and add the fluid as required 2 On the inner parts of the master cylinder and caliper cylinder replace the oil seals every tw...

Page 25: ...d after every race Before lubricating thoroughly clean the machine of sand dirt and water A Use Yamaha cable lube or WO 40 on these areas B Use chain lube or SAE 30 50 motor oil A A All control cables Brake and clutch lever pivots A Kick starter lever pivot Footpeg pivots 2 3 A Shift lever pivot B Drive chain ...

Page 26: ...d avoid getting grease on the brake shoes Clutch wire ends Wheel axles and pivot shaft Rear wheel bearing and oil seal Relay arm bearing and oil seal Connecting rod bearing and oil seal Rear shock pivot upper and lower 2 4 Wheel axle collar Swingarm bearing bushing and oil seal Steering head bearings ...

Page 27: ...ion timing For Engine Service 1 Clutch holding tool YM 91042 Use this tool to hold the clutch boss while removing or tightening the clucth boss nut 2 5 2 Crankcase separating tool YU Ol135 This tool is used to split the crankcases as well as remove the crankshaft from either case 3 Crankshaft installing tool YU 90058 14 I Spacer YU 90059 5 Crankshaft installing bolt and adapter YU 90060 YU 900621 ...

Page 28: ...S Spark Plug Standard Spark Plug Type BSES NGK Gap 0 7 O S mm 0 03 0 031 in Side electrode 1 Whenever a new spark plug is installed the gap must be checked and adjusted properly Use a wire feeler gauge to check the gap and adjust the gap by bending the side electrode gently 2 Be sure to clean the gasket surface and threads before installing the spark plug Torque the plug to specification Spark plu...

Page 29: ... being turned in the same direction Zero the dial gauge at TOC 5 From TOC rotate the rotor clockwise until the dial gauge indicates that the piston is at a specified distance from TOC At this point the scribed marks on the rotor and the stator plate should be aligned 2 7 Ignition timing B T O C 1 27 O l mm O 05 O 004 in 1 Rotor mark 2 Stator mark 3 Crankcase mark 6 If the marks are not aligned loo...

Page 30: ...s the top speed and turnning it out increases the top speed CD Adjuster Locknut 2 8 WARNING Particularly for a beginner rider the speed limiter should be screwed in completely Screw it out little by lit tle as his riding technique improves Never remove the speed limiter from the outset For proper throttle lever operation do not turn out the adjuster more than 12 mm 0 47 in Idle Speed 1 Screw in th...

Page 31: ...his would allow dirt and dust to enter the engine and cause rapid wear and possible engine damage In ad dition carburetor jetting would be signi ficantly affected with subsequent poor performance and possible overheating 2 9 1 Remove the seat and upper cover 2 Remove the air filter box cover and air filter element 3 Separate the element from the filter cage 4 Wash element gently but thoroughly in ...

Page 32: ...mechanical adjustment refer to Clutch mechanism adjustment 2 10 Front Brake Adjustment The free play at the end of the adjuster should be 0 5 1 0 mm 0 0197 0 0394 in 1 Loosen the locknut 2 Turn the adjuster so that the brake lever movement at the adjuster end is 0 5 1 0 mm 0 0197 0 0394 in before the ad juster contacts the master cylinder piston 3 After adjusting tighten the locknut 1 Adjuster 2 L...

Page 33: ...rubber seals may deteriorate causing leakage and poor brake performance Recommended brake fluids DOT 3 1 Lower level 2 11 1 Lower level 2 Refill with the same type of brake fluid mixing fluids may result in a harmful chemical reaction and lead to poor performance 3 Be careful that water does not enter the master cylinder when refilling Water will significantly lower the boiling point of the fluid ...

Page 34: ...36 ft lb Lower wheel hub bolt 80 Nm 8 0 m kg 58 ft lb 2 12 Drive Chain Cleaning and Lubrication This machine has a drive chain with small rub ber O rings between the chain plates Steam cleaning high pressure washes and certain solvent can damage these O rings Use only kerosene to clean the drive chain Wipe it dry and thoroughly lubricate it with SAE 30 50 motor oil Do not use any other lubricants ...

Page 35: ...heck steering adjustment to make sure there is no binding when the forks are moved from lock to lock If necessary repeat the adjustment procedure 2 13 Wheel Bearings If a rolling rumble is noticed and increases with increasing wheel speed not engine or transmission speed the wheel bearings may be worn Check the wheel bearings for both the front and rear wheels Front wheel 1 Oil seal 2 Bearing Tire...

Page 36: ...cock gasket surfaces are scratched or corroded the fuel cock assembly must be replaced If there is abrasive damage to any com ponents the fuel tank must be drained and flushed 4 Reassemble the fuel cock and install it 5 Connect the fuel pipe Tires WARNING This model is equipped with low pressure tires Pay attention to the following points Recommended tire pressure Front 24 5 kPa 0 25 kg cm2 3 56 p...

Page 37: ...5 Excessive tire wear will result from riding on paved surfaces Cable Inspection and Lubrication 1 Damage to the outer housing of the various cables may cause corrosion Often free movement will be obstructed An unsafe condition may result Replace such cables as soon as possible 2 If the inner cables do not operate smoothly lubricate or replace them Recommended lubricant Yamaha Chain and Cable Lube...

Page 38: ...ssary adjust the headlight beam as follows 1 Vertical adjustment To adjust the beam to the upper turn the adjusting screw clockwise To adjust the beam to the lower turn the adjsuting screw counterclockwise 1 Vertical adjusting screw 2 16 ...

Page 39: ...2 17 ...

Page 40: ... Inspection 3 9 EXHAUST PIPE AND MUFFLER 3 10 Removal 3 10 Maintenance 3 10 CYLINDER HEAD 3 11 Removal 3 11 Maintenance 3 12 CYLINDER 3 13 Removal 3 13 Maintenance 3 13 PISTON 3 14 Removal 3 14 Maintenance 3 14 Piston Clearance 3 15 Piston Rings 3 15 Piston Pin Bearing 3 16 Assembly 3 16 CRANKCASE COVER 3 17 Removal 3 17 Assembly 3 17 WATER PUMP 3 18 Disassembly 3 18 Inspection 3 18 Assembly 3 18 ...

Page 41: ...ection 3 25 Installation 3 25 ENGINE REMOVAL 3 26 ENGINE MOUNTING 3 27 CRANKCASE 3 27 Crankcase Disassembly 3 28 TRANSMISSION AND SHIFTER 3 29 Inspection 3 29 Bearing and Oil Seals 3 30 Transmission Installation 3 30 CRANKSHAFT 3 31 Inspection 3 31 Crankshaft Installation 3 32 COOLING SySTEM 3 33 Radiator Removal 3 34 Thermostatic Valve Removal 3 34 Cooling System Checks 3 34 ...

Page 42: ...their removal When replacing parts always use the genuine Yamaha article to maintain optimum performance durability and safety All gaskets and seals should be replaced during engine work and all gasket sur faces should be clean During assembly always apply oil or grease to bearing surfaces to protect them upon initial start up Replace all circlips which are distorted from use or disassembly Always...

Page 43: ...CARBURETOR 3 2 Needle jet P 4 Float pin ...

Page 44: ...el for a given volume of air conversely an engine running too lean needs more fuel for the air being taken in AIR FUEL MIXTURE 10 1 CD 12 1 r 1 14 1 16 1 18 1 20 40 60 80 100 THROTTLE VALVE OPENING 1 Maximum power mixture ratio 2 Theoretical mixture ratio 3 3 12 13 9 CD TO DEVELOP MAXIMUM POWER ONE GRAM OF FUEL IS REQUIRED PER 12 TO 13 GRAMS OF AIR 1 Fuel 2 Air Tuning changes usually are required ...

Page 45: ...ng six carburetor components The six components and their relative positions in the carb are shown in the illustration below The main jet should be increased or decreas ed one to five sizes by test until the engine gives maximum power Symptoms of improper settings If your machine exhibits one or more of the symptoms listed below it may need carb tun ing changes Before attempting any changes howeve...

Page 46: ...stamped on the bottom or side of the jet indicates the relative size of the hole in the jet which meters fuel The larger the number on the main jet is the bigger the hole and the 3 5 more fuel it will pass hence larger numbers mean richer jetting Smaller numbers of course mean leaner jetting Make main jet changes one step at a time 1 Jet number Jet needle and needle jet The jet needle and needle j...

Page 47: ...e cutaway The height of the cutaway determines the characteristic of the airflow The height is indicated by the number stamped on the bottom of the throttle valve A smaller number means a smallar cutaway and a smaliar cutaway provides a richer mix ture Conversely a lager cutaway makes the mixture leaner Make throttle valve changes in increments of 0 5 3 6 CD __ _ 1 Cutaway 2 Slide number Pilot jet...

Page 48: ...he proper strength of the mixture varies depending on atmospheric conditions pres sure humidity and temperature Taking these conditions into consideration ad just the carburetor settings properly Take a note of carburetor settings as well as weather conditions course conditions and lap times so they can be utilized as reference data for future races 3 7 Tuning and Repair Parts Part name Size Part ...

Page 49: ...t reservoir tank 2 Loosen the joint clamp screws and disconnect the fuel hose I 1 Fuel hose 3 8 Inspection 1 Examine carburetor body and fuel passages If contaminated wash car buretor in petroleum based solvent Do not use caustic carburetor cleaning solu tions Blowout all passages and jets with compressed air 2 Examine condition of floats If floats are damaged they should be replaced 3 Inspect inl...

Page 50: ...pply suction to carburetor side of assembly Leakage ould be slight to moderate 3 Check valve stopper height If beyond tolerance adjust or replace 3 9 Valve stopper height 9 4 0 2 mm 0 370 0 008 in 1 Valve stopper height If it is 0 3 mm 0 012 in more or less than specified replace the valve stopper 4 Check reed valve for bending If beyond tolerance replace reed valve Reed valve bending limit 0 6 mm...

Page 51: ...250 3 Remove the muffler 3 10 Maintenance 1 Using a rounded scraper remove excess carbon deposits from manifold area of ex haust pipe 2 Check the exhaust pipe and muffler mounting bracket for cracks If it has ex cessive cracks repair or replace it 3 When the muffler gets a large carbon build up inside remove the outlet pipe and decarbonize ...

Page 52: ...d cylinder and clutch thoroughly drain the coolant 1 Drain the transmission oil 3 11 Spark plugs B8ESINGK Gap 0 7 0 8 mm 0 028 0 031 in 113 Nm 1 3 m kg 10 tt lb 1 2 Drain off the coolant from the cooling system See paragraph Coolant draining 3 Remove the spark plug lead wire and spark plug Disconnect radiator hoses at cylinder head ...

Page 53: ...nd head gasket And discard it 3 12 Cylinder head nut 25 Nm 2 5 m kg 18 ft lb Maintenance 1 Using a rounded scraper remove cabon deposits from combustion chamber Take care to avoid damaging the spark plug threads Do not use a sharp instrument Avoid scratching the metal surface 2 Place the head on a surface plate There should be no warpage Correct by resur facing Place 400 600 grit wet emery sandpap...

Page 54: ...e cylinder and base gasket and discard the gasket 3 13 Maintenance 1 Using a rounded scraper remove carbon deposits from the exhaust port 2 Check cylinder bore Using a cylinder hone remove any scoring Hone lightly using smooth stones Hone no more than required to avoid excess piston clearance 3 Using a cylinder gauge set to standard bore size measure the cylinder Measure front to rear and side to ...

Page 55: ... clip NOTE _______________________ If the pin hangs up use a piston pin puller Do not hammer on pin as damage to rod piston and bearing will result 3 14 End gap 0 35 0 5 mm 0 014 0 019 in Piston clearance 0 060 0 065 mm 0 0024 0 0026 in I6206C4I ISD _5 121 Maintenance 1 Using a rounded scraper remove carbon deposits from piston crown and ring grooves ...

Page 56: ...he piston to cylinder clearance subtract the piston skirt diameter from the cylinder inside diameter Ifthe nominal piston clearance is not within tolerance replace the piston or bore the cylinder as required PISTON CLEARANCE Cylinder inside diameter Piston skirt deiameter Exsample 68 020 mm 2 678 in 67 960 mm 2 675 in 0 060 mm 0 002 in Std piston clearance 0 060 0 065 mm 0 0024 0 0026 in Piston Ri...

Page 57: ...blued replace both 3 Check the bearing cage for excessive wear Check the rollers for signs of flat spots If found replace pin and bearing 3 16 Assembly 1 During re assembly always use a new cylinder base gasket NOTE _______________________ Be sure to tighten the cylinder head nuts to specification Cylinder nut torque 35 Nm 3 5 m kg 25 ft Ib Cylinder head nut torque 25 Nm 2 5 m kg 18 ft Ib 2 During...

Page 58: ... assembly 3 Remove the kickstart lever and cover 4 Remove the right hand crankcase cover 3 17 Assembly For reassembly reverse the procedure for disassembly while taking the following care 1 Install the dowels new gasket and crankcase cover 1 Dowel 2 Tighten the following components Crankcase cover 12 Nm 1 2 m kg 9 ft Ib Footrest bracket 55 Nm 5 5 m kg 40 ft ib ...

Page 59: ...mpeller and water pump housing 2 Check the impeller for cracks and damage Replace if necessary 3 Check for wear of the impeller and replace it as required 4 Check the oil seal and bearing for damage and wear If damag d or worn excessive ly replace the oil seal and bearing as a set NOTE _______________________ When installing the oil seal make sure the WATER SIDE mark is on the outside Assembly lQ ...

Page 60: ...owing care 1 When installing the impeller shaft apply a grease to oil seal and impeller shaft And install the shaft while turning it NOTE _______________________ Take care so that the oil seal lip is not damag ed or the spring does not slip off its position KICK STARTER 3 19 ...

Page 61: ...ar if wear or damage is found 2 The pressure required to move the kick clip on the kick gear should be about 1 0 kg 2 2Ib If the pressure required is more or less than this amount the kick starter will malfunction the kick clip must be replaced Assembly 1 Slide the shaft into the case make sure the kick clip fits into its groove in the crankcase 2 Turn the kick starter return spring clockwise and ...

Page 62: ... j 85 ft lb 11 5m kg t 1115 Nm Apply grease e gear Primary dnv Push lever assembly Removal mary drive gear nut 1 Loosen the pn 6 holding the ve the phillips screws the clutch 2 Remo Remove d ressure plate te and push r p gs pressure pIa and friction spnn clutch plates NOTE d ug CD or lead between Piece of rolle r Place a drive gears pnmary Remove the plates 3 21 ...

Page 63: ...iven gear clutch housing 1 Clutch holding tool 4 Remove the primary drive gear 5 Remove the push rod ball and push rod 6 Pull out the clutch push lever assembly 7 Remove kick starter idle gear 3 22 Maintenance 1 Measure the friction plates at three or four points If their minimum thickness ex ceeds tolerance replace New Wear limit Friction plate 3 0mm 2 7mm thickness 1O 12in O 106in 2 Place each c...

Page 64: ...ng as a set New Min Clutch spring 34 9mm 33 9mm free length 1 37in 1 33 in 5 Ro the push rod across a surface plate If rod is bent replace 3 23 6 Inspect the clutch push lever If excessive ly worn repair using 300 400 grit sand paper or replace Installation Reverse the removal procedure while taking the following care 1 Insta the kick starter idle gear 2 Insta the primary drive gear and washer 1 D...

Page 65: ...ear nut 3 24 Primary drive gear nut torque 115 Nm 11 5 m kg 85 ft lb Mechanism Adjustment 1 Disconnect the clutch cable at push lever end 2 Turn the push lever to align the push lever with the crankcase edge Align the edge of push lever to the crankcase edge 3 Loosen the short push rod locknut and turn the short push rod in or out until it lightly seats against a push rod ball Tighten the locknut ...

Page 66: ...bly 2 Stopper lever 3 25 Inspection 1 Inspect shift return spring A broken or worn spring will impair the return action of the shifting mechanism 2 Inspect change lever assembly for ben ding of shaft worn or bent spline and broken or worn shift arm spring A bent shaft will cause hard shifting 3 Inspect the segment for wear or damage replace as required Installation 1 Engage the shift return spring...

Page 67: ...k plug lead 5 Remove the cylinder head holding brackets and coolant hose 6 Disconnect the clutch cable 3 26 7 Disconnect fuel pump suction hose and C D I leads 8 Remove the rear brake tank change pedal and drive chain cover 9 Remove the nut lock washer and drive sprocket 10 Remove the front and center lower moun ting bolt Remove pivot shaft 1 Front mounting bolt 3 Pivot shaft 2 Center lower mounti...

Page 68: ... care 1 Install engine mounting bolts and nuts with proper tightening torque CRANKCASE 3 27 Bolt Tightening torque Bracket to frame 30Nm 3 0 m kg 22 ft Ib Front Bracket to engine 30Nm 3 0m kg 22ft Ib Center Lower 30Nm 3 0 m kg 22 ft Ib Bracket to frame 30Nm 3 0 m kg 22 ft Ib Upper Bracket to engine 55 Nm 5 5 m kg 40 ft lb Pivot shaft nut 85 Nm 8 5 m kg 60 ft lb When installing the pivot shaft grea...

Page 69: ...___ Tighten the securing bolts on the crankcase separating tool but make sure the tool body is parallel with the case If necessary one screw may be backed out slightly to level tool body 1 Crankcase separating tool Use a soft hammer to tap on the case half Tap only on reinforced portions of case Do not tap on gasket mating surface Work slowly and carefully Make sure the case halves separate evenly...

Page 70: ...t m gear 22T J 6th pinion gear 130X17X131 24T 3 29 2nd pinion gear 15T 75 Nm 7 5 m kg 54 ft lb NOTE _______________________ Remove assembly carefully Note the position of each part Pay particular attention to the location and direction of shift forks Inspection 1 Inspect each shift fork for signs of gall ing on gear contact surfaces Check for bending Make sure each fork slides freely on its guide ...

Page 71: ...ngs rotate inner race with a finger If rough spots are noticed replace the bearing 3 30 NOTE _______________________ Bearing s are most easily removed or install ed if the cases are first heated to approximately 900 120 C 1940 248 F Bring the case up to proper temperature slowly Use an oven 2 Check oil seal lips for damage or wear Replace as required 3 Always replace crankshaft oil seals whenever ...

Page 72: ...haft a ring for damage 4 After reassembly apply a liberal coating of two stroke oil to the crank pin and bearing and into each crankshaft bearing oil delivery hole 5 Check crankshaft and transmission shafts for proper operation and freedom of movement 3 31 CRANKSHAFT 1 Remove crankshaft assembly with crankcase separating tool 1 Crankcase separating tool Inspection F 6A 1 Mount the dial gauge at ri...

Page 73: ...ir is required Take the machine to your authorized Yamaha dealer Crankshaft Installation 1 Set the crankshaft into left case half and install crankshaft installing tool 1 Spacer 3 Adapter 2 Crankshaft installing pot 4 Crankshaft installing bolt To protect the crankshaft against scrat ches or to facilitate the operation of in stallation Pack the oil seal lips with grease Apply engine oil to each be...

Page 74: ...COOLING SYSTEM i rf Radiator J I L 3 33 ...

Page 75: ...static Valve Removal 1 Disconnect the thermostatic switch lead and radiator hose Remove the ther mostatic valve 3 34 2 Remove the thermostat cover and ther mostatic valve from the thermostat housing Cooling System Checks 1 Check the radiator core for clogged or flat tened fins If more than 20 of the radiator core area is flattened repair or replace the radiator core If the radiator is clogged clea...

Page 76: ... drop replace the radiator filler cap Valve opening pressure 93 2 122 6 kPa 0 95 1 25 kg cm2 13 5 17 8 psi 3 35 5 Suspend thermostatic valve in a vessel of water that contains a reliable ther mometer Heat the water slowly Then note the ther mometer reading while stirring the water continually The thermostatic valve should begin to open at 63 67 C 145 4 152 6 F 1 Thermometer 2 Full open 3 Begin to ...

Page 77: ...3 36 ...

Page 78: ... 4 4 Brake Inspection and Repair 4 5 Brake Assembly 4 6 REAR BRAKE 4 8 Brake Pad Replacement 4 8 Caliper Disassembly 4 8 Master Cylinder Disassembly 4 8 Brake Inspection and Repair 4 8 Brake Assembly 4 8 FRONT FORK 4 9 Fork Oil Replacement 4 12 Removal and Disassembly 4 13 Inspection 4 14 Assembly 4 14 STEERING HEAD 4 17 Adjustment 4 18 Removal 4 18 Inspection 4 19 Installation 4 19 REAR SHOCK MON...

Page 79: ...SWINGARM 4 25 Swingarm Free Play Inspection 4 26 Removal 4 26 Inspection 4 27 Assembly 4 28 DRIVE CHAIN 4 29 ...

Page 80: ...the front fork Front Axle Inspection Remove any corrosion from the axle with emery cloth Place the axle on a surface plate and check for bend If bent replace the axle Do not attempt to straighten a bend Front Wheel Inspection 1 Check for cracks bends or warpage of the wheels If a wheel is deformed or cracked it must be replaced 4 1 2 Check wheel runout If deflection exceeds tolerance below check t...

Page 81: ... grease the lips of the front wheel oil seals Use lightweight lithium soap base grease 2 Tighten the front axle and pinch bolt TIGHTENING TORQUE Front axle 58 Nm 5 8 m kg 42 ft lb Pinch bolt 20 Nm 2 0 m kg 14 ft lb 4 2 REAR WHEEL Removal 1 Block the front tire and jack up the rear of the vehicle Apply the rear brake 2 Remove the cotter pin and axle nut 1 Cotter pin 2 Axle nut 3 Remove the rear whe...

Page 82: ...ystem should be disassembled drained cleaned and then properly filled and bled upon reassembly Do not use solvents on brake internal components Solvents will cause seals to swell and distort Use only clean brake fluid for cleaning Use care with brake fluid Brake fluid can injure your eyes and it will damage painted surfaces and plastic parts Brake Pad Replacement 1 Remove the caliper bolts and cal...

Page 83: ... Place the open hose end into the con tainer and pump the old fluid out of the master cylinder 3 Remove the caliper cylinder securing bolts from the front fork 4 Remove the retaining bolt pads and pad spring 5 Carefully force the piston out of the caliper cylinder with compressed air Never try to pry out the piston WARNING Cover the piston with a rag Use care so that the piston does not cause inju...

Page 84: ...e the brake pads as a set See Brake Pad Replacement for a listing of the parts to be replaced when pads are replaced 4 5 Wear limit 0 8 mm 0 032 in 1 Wear limit 3 Replace the piston seals if damaged Replace the seals every two years 4 Inspect the master cylinder body replace if scratched Clean all the passages with new brake fluid 5 Inspect the brake hoses Replace the hoses every four years or imm...

Page 85: ...o the caliper cylinder Torque the retaining bolt to specification TIGHTENING TORQUE 23 Nm 2 3 m kg 17 ft lb 3 Apply rubber grease to the piston seals caliper cylinder and piston 4 Install the caliper assembly on the front fork Torque the bolts to specification TIGHTENING TORQUE 35 Nm 3 5 m kg 25 ft lb 4 6 5 Attach the brake hoses TIGHTENING TORQUE 26 Nm 2 6 m kg 19 ft lb 6 If the brake disc has be...

Page 86: ...tube 4 5 mm 3 16 in inside diameter tightly to the caliper bleed screw Put the other end of the tube into a container 3 Slowly apply the brake lever several times Pull in the lever Hold the lever in this on position Loosen the bleed screw Allow the lever to travel slowly toward its limit When the limit is reach ed tighten the bleed screw Then release the lever 4 Repeat the above procedure until al...

Page 87: ...s 1 Remove the retaining bolt from the caliper cylinder Then remove the pads and pad spring 1 Retaining bolt 2 Follow the Front Brake Pad Replace ment 3 and 4 Caliper Disassembly Refer to FRONT BRAKE Master Cylinder Disassembly 1 Loosen the locknut and remove the master cylinder securing bolts Disconnect the brake hoses 4 8 1 Locknut 2 Brake hose 2 Remove the master cylinder from brake pedal by tu...

Page 88: ...FRONT FORK Damper rod t bo g Dustseal snapring Oilseal Oil seal washer Slide metal Inner tube slide bushing Taper spindle Drain screw 8 Damper rod bolt 120 Nm 2 0 m kg 14 ft lb I 4 9 ...

Page 89: ... When the oil level is lowered The air spring in the later half stage of travel is lessened and thus the front fork is softer EX 300 FORK STROKE 1 Increase level 2 Std oil level 3 Decrease level 4 10 Oil level adjustment 1 Place a suitable stand under the engine to keep the front of machine raised off the floor 2 Remove the valve cap 3 Using a slotted head screwdriver depress the valve to allow th...

Page 90: ...ghout the entire range of fork travel WEIGHT 1 0 2 kg cm2 3 Coil spring FORK STROKE 2 0 kg cm2 Air coil spring 4 11 Increase air pressure causes initial load to increase and the fork becomes hard Decrease air pressure causes initial load to decrease and the fork becomes soft Remember 0 psi air pressure in forks and release any pressure build up after each moto 1 Place a suitable stand under the en...

Page 91: ...______________ Check gasket replace if damaged 7 Measure the correct amount of oil and pour it into each leg After filling allow it a few minutes and slowly pump the inner tube up and down 2 or 3 times so that air can be extracted from the oil 4 12 Recommended oil Fork oil 10 wt or SAE lOW motor oil Oil quantity 418 cm3 14 7 Imp OZ 13 9 US oz 8 Inspect the a ring on the cap bolt if it is cut or ot...

Page 92: ...5 Remove the dust seal and snap ring from the top of the outer tube 4 13 1 Dust seal 2 Snap ring 6 Fill the fork completely with fork oil and reinstall the cap bolt Depress the air valve until oil flows out 7 Place a spacer on top of the cap bolt and place the fork leg in a hand press as il lustrated The spacer will keep the press from contacting the air valve If the inner tube is abruptly contrac...

Page 93: ...be for scratches and straightness If the tube is severely scratched or bent it should be replaced WARNING Do not attempt to straighten a fork tube since this may weaken the part dangerously 2 Inspect the slide metal If damaged or ex cessively worn replace it 3 Check the seal outer seat If leakage is from this area replace the seal If this does not care the leakage replace the outer tube 4 Check th...

Page 94: ...pecial tool 4 15 1 Snap ring 2 Dust seal 8 Pour the specified amount of recom mended fork oil into the inner fork tube Recommended oil Oil capacity 418 cm3 14 7 Imp zo 13 9 US zo Fork oil 10 wt or SAE 10 fork oil 9 After filling slowly pump the outer tubes up and down to distribute the oil 10 Install the long spring washer short spring and the cap bolt 11 Fill the air and set it to specification I...

Page 95: ...13 Install the brake caliper Brake caliper bolt 35 Nm 3 5 m kg 25 ft lb 14 Install the front wheel Front axle 58 Nm 5 8 m kg 42 ft lb Pinch bolt 20 Nm 2 0 m kg 14 ft lb 4 16 ...

Page 96: ...1 Tighten 45 Nm 4 5 m kg 32 ft lb 2 Loosen 1 4 turn 23 Nm 2 3 m kg 17 ft lb Steering stem nut Steering crown 85 Nm 8 5 m kg 61 ft lb J Ring nut cover Ballrace Ball 19 pes d B Y i r 1 7 40 Nm 4 0 m kg 29 ft lb Lj 4 17 ...

Page 97: ...r and lower upper pinch bolts 1 Upper pinch bolt 2 Lower upper pinch bolt 3 Disconnect the headlight lead and pilot light lead Remove headlight assembly 4 Remove the brake hose clamp and front fender 4 18 o G 5 Disconnect the throttle cable and clutch cable 1 Throttle cable 6 Remove the handlebar assembly 7 Remove the fuel and coolant reservoir tank breather hoses Remove the steering stem nut and ...

Page 98: ...ball race of the upper bearing and arrange the balls around it Then apply more grease and set the top race into place NOTE _______________________ Use medium weight wheel bearing grease of quality manufacture preferably waterproof 4 Carefully slip the under bracket stem up into the steering head Hold the top bear ing assembly in place so the stem does not knock any balls out of position 5 Set the ...

Page 99: ...r bracket holes with steering crown holes 7 Install the front forks headlight assembly front fender and front wheel TIGHTENING TORQUE Steering crown inner tube 40 Nm 4 0 m kg 29 ft lb Under bracket inner tube 20 Nm 2 0 m kg 14 ft lb Handlebars upper holder 23 Nm 2 3 m kg 17 ft lb 4 20 ...

Page 100: ...REAR SHOCK MONOCROSS SUSPENSION DE CARBON SYSTEM 4 21 ...

Page 101: ...rn out the adjuster more than 25 clicks from the stiffest position Compression damping STD SETTING 10 clicks in 1 Compression damping adjuster 2 Match marks Don t turn out the adjuster more than 20 clicks from the softest position WARNING The compression damping adjuster is very hot immediately after a run Never allow your bare hand or part of your body to touch it Shock spring Type Spring rate Pa...

Page 102: ...t to damage any part of the hose Any brake in the hose may result in a spurt of oil under high pressure 5 Take care not to scratch the contact surface of the piston rod with the cylinder or oil could leak out 6 Never attempt to remove the plug at the bottom of the nigrogen gas tank It is very dangerous to remove the plug 7 Never attempt to remove the banjo bolts where the hose attaches to the mono...

Page 103: ...ervoir 5 Remove the rear shockabsorber assembly Push down the spring remove the spring retainer and remove the spring 4 24 1 Retainer III SIBIIBtIOn 1 Install the spring and spring retainer 2 Tighten the locknut TIGHTENING TORQUE 69 Nm 6 9 m kg 50 ft lb 3 Apply grease to the collars bushings and oil seals 4 Install the shockabsorber assembly Upper bolt 32 Nm 3 2 m kg 23 ft lb Lower bolt 32 Nm 3 2 ...

Page 104: ...SWINGARM 48 Nm 4 8 m kg 35 ft lb 85 Nm 8 5 m kg 60 ft lb Relay arm Lithium base grease 4 25 ...

Page 105: ...0757 0 0118 in 3 Closely inspect the swingarm for cracks or other damage and repair or replace it as required 4 When reinstalling the swingarm be sure to grease the bearings bushings and oil seal lips 5 Grease the pivot shaft install it and its nut and torque the nut to specification Pivot shaft nut torque 85 Nm 8 5 m kg 60 ft lb Removal 1 Remove the rear wheel assembly 2 Remove the rear axle ring...

Page 106: ...cation of spacing washers and shims They must be reinstalled in the same positions 9 Remove the relay arm and the connect ing rod Inspection 1 Measure the swingarm side clearance Std swingarm side clearance 0 2 0 3 mm 0 00787 0 0118 in If the swingarm side clearance is out of standard select the proper shim quanti ty so that they conform to the standard swingarm side clearance t 1r f f A Shim posi...

Page 107: ... mounting positions and check for the rear axle at both ends 1 Rear axle 2 Dial gauge Rear axle runout limit 1 5 mm 0 06 in If the runout exceeds 1 5 mm 0 06 in replace the rear axle with a new one Assembly Assemble the swingarm by reversing the removal procedure Take care of the following precautions 1 Apply grease to the portions of the swingarm Bush Coat all inside surface of bushes with grease...

Page 108: ...ile holding the outside ring nut 240 Nm 24 m kg 170 ft Ib WARNING Always use the new cotter pin on the ax le nut 4 29 DRIVE CHAIN 1 Remove the change pedal and drive sprocket cover 2 Remove the master link clip and discon nect the drive chain 3 Inspect the teeth on the rear sprocket if they are worn as shown in the illustra tions below replace the sprockets and chain as a set 1 Slip off 2 Bend tee...

Page 109: ...installing the driven sprocket light ly smear grease on the fitting bolts Driven sprocket securing nut torque 30 Nm 3 0 m kg 22 ft lb Be sure to lock the nut with the lock washer 7 During reassembly the master link clip must be installed with the rounded end facing the direction of travel NOTE _______________________ The chain should be cleaned and lubricated after every use of the machine 4 30 _ ...

Page 110: ...II ELECTRICAL TROUBLESHOOTING YTZ250S WIRING DIAGRAM 5 2 IGNITION SySTEM 5 3 LIGHTING SySTEM 5 7 SIGNAL SySTEM 5 11 ...

Page 111: ...5 1 ...

Page 112: ... Engine stop switch 3 Voltage regulator 4 Headlight 5 Pilot light checker 6 Pilot light 7 Taillight 8 Thermostatic switch 9 Spark plug 10 Ignition coil 11 COl Unit 12 COl Magneto 13 Br tube f j 5 2 RUN OFF COLOR CODE W R White Red B W Black White B Black 0 Orange Br Brown Y R Yellow Red G L Green Blue Y Yellow G Green ...

Page 113: ...IGNITION SYSTEM Circuit Diagram 5 3 ...

Page 114: ...ubleshooting If the ignition spark is of poor quality or if there is no spark at all use the following procedure to locate and repair the problem Q 5 4 1 Spark plug test Remove the spark plug and check the spark Groung the spark plug cap to the cylinder head and kick the starter NOTE ______________________ If the spark plug is oily or has carbon deposits clean it or replace L __ I I No spark I ...

Page 115: ... Disconnect the Black White and Black leads of engine stop switch at C D I unit and use the pocket tester to check the resistance of the engine stop switch Switch RUN OFF Tester 00 on 5 5 1 1Faulty Replace the switch o 4 C D I Magneto Source coil test Disconnect the magneto leads and use the pocket tester to check the resistance of the magneto coils Source coil resistance Brown Black 315U 10 If ot...

Page 116: ...s of joining ends 2 Keep the connectors and couplers from dirt or rust Wrong ICorrect I connection OK 5 6 Q 7 Ignition coil test Use the pocket tester to check the resistance of primary and secondary windings of the ig nition coil Primary coil resistance 0 290 15 If other than specified Secondary coil resistance 4 0kO 15 Replace I l ignition coil Replace C D I unit L ______ Make sure the wire harn...

Page 117: ...LIGHTING SYSTEM 5 7 ...

Page 118: ...light C D I Magneto Troubleshooting Headlight and taillight do not come on when engine is running 3 Headlight Taillight bulbs Remove the headlight and taillight bulb and check the bulb CD Headlight bulb CD Taillight bulb IFaulty 1 1 I Replace the bulb 1 Q 5 8 ...

Page 119: ...switch CD Yellow Red lead Check the voltage regulator and replace if necessary 1 12V and less than Disconnect the lightldimmer switch leads and use the pocket tester to check the resistance of the switch OFF Y R L G and Y LOW Y R G HI Y R Y Switch OFF LOW HI Tester 00 on on IReplace the switch I L _ _ _ _ INo Voltage I Q 5 9 ...

Page 120: ...ck the resistance of the magneto coil CD Y R lead Lighting coil resistance Yellow Red Black 0 580 10 Replace lighting coil o 4 Connectors check up 1 Check the connectors and couplers for looseness of joining ends 2 Keep the connectors and couplers from dirt or rust Wrong Correct connection 5 10 ...

Page 121: ...SIGNAL SYSTEM G l 5 11 ...

Page 122: ...itch C D I magneto Troubleshooting The pilot light does not come on For 3 seconds when engine is turned on When the coolant temperature is more than 98 C 208 4 F 1 Pilot bulb Remove the pilot bulbs and check them 1Faulty 1 1 1Replace the bulb 1 5 12 ...

Page 123: ... C less than 208 4 F Test 1 2 Heat up tests Test 3 4 Cool down tests 105 3 C 221 0 37 4 F CD bbbd6b 1 Temperature gauge 2 Thermostatic switch 3 Pocket tester Pocket tester nx1 Discontinuity Continuity Continuity Discontinuity o X H IFaulty 1 Replace the thermostatic switch Q 5 13 3 C D I Magneto Lighting coil test Refer to LIGHTING SYSTEM Troubleshooting NO 3 Q 4 Connectors check up Refer to LIGHT...

Page 124: ...ed performance 6 2 Overheat 6 3 Low coolant level 6 3 Transmission and shifter 6 4 Clutch 6 4 Chassis 6 5 SPECIFICATIONS 6 6 GENERAL TORQUE SPECiFiCATIONS 6 16 DEFINITION OF UNITS 6 16 CONVERSION TABLES 6 17 CABLE ROUTING 6 18 WARRANTY INFORMATION 6 22 NOISE REGULATION 6 23 MAINTENANCE RECORD 6 23 ...

Page 125: ... is worn or Repair or replace scratched 3 Compression leaks passing cylinder Replace or repair head gasket Head is distoreted 4 Crankshaft side oil seal is faulty Replace 5 Air leaks through crankcase Repair sealing surfaces Air Fuel System Possible Cause Remedy 1 Carburetor pilot jet is clogged Clean 2 Fuel petcock or pipe is clogged Clean 3 Float valve is faulty Replace remove gasoline from Floa...

Page 126: ...place crankcase sealing surfaces or crankshaft side oil seal 4 Carbon deposits in combustion Decarbonize chamber Piston Cylinder head 5 Power valve malfunctions Repair or replace Air Fuel System Possible Cause Remedy 1 Clogged carburetor jets Clean 2 Improperly adjusted main jet Adjust High speed 3 Improperly adjusted jet needle Adjust Medium speed 4 Incorrect fuel lever Adjust 5 Dirty or clogged ...

Page 127: ... gas Replace mixing ratio is incorrect 7 Coolant of inferior quality Replace with specified type 8 Coolant level is low Add up to specified line 9 Water pump is faulty Repair or replace 10 Cooling passage is clogged Clean passage 11 Radiator is clogged Clean radiator Low coolant level Possible Cause Remedy 1 Radiator is leaky Repair or replace 2 Hose is damaged or joint is loose Replace hose or re...

Page 128: ...are broken Removal Replace Shift pedal does not 1 Change return spring is broken Replace return 2 Change shaft is bent Replace Clutch Trouble Possible Cause Remedy Clutch slips 1 Friction plate is worn Replace 2 Clutch plate is worn Replace 3 Clutch spring is fatigues Replace 4 Pressure plate is deformed Replace 5 Clutch play is too small Adjust 6 Clutch adjustment is incorrect Adjust 7 Match mark...

Page 129: ...uble Possible Cause Remedy Faulty 1 Brake pad are worn Replace 2 Brake is improperly adjusted Adjust 3 Brake pad is greasy Degrease or replace Not return smoothly 1 Return spring is broken Replace 2 Brake pedal axle is starved for grease Grease 3 Brake fluid leaking Replace damaged parts and bleed air Frame and Swingarm Possible Cause Remedy 1 Frame is cracked Weld reinforce or replace 2 Swingarm ...

Page 130: ...on Cylinder Arrangement Single cylinder forward inclined Displacement 246 cm3 Bore x Stroke 68x68 mm 2 677 x 2 677 in Compressin Ratio 7 7 1 Starting System Kick starter Lubrication Sytem Premix 24 1 Yamalube R Premix 20 1 Castrol R30 Castrol A545 Castrol A747 Oil Type or Grade 2 Cycle Transmission Oil SAE 10W30SE Periodic Oil Change 1 00 L 0 88 Imp qt 1 05 US qt Total Amount 1 05 L 0 92 Imp qt 1 ...

Page 131: ...ion Ratio 63 24 2 625 Secondary Reduction System Chain drive Secondary Reduction Ratio 44 13 3 384 Transmission Type Constant mesh 6 speed Operation Left foot operation Gear Ratio 1st 31 13 2 384 2nd 29 15 1 933 3rd 27 18 1 500 4th 24 20 1 200 5th 22 22 1 000 6th 20124 0 833 6 7 ...

Page 132: ...e Single disc Operation Right hand operation Rear Brake Type Single disc brake Operation Right foot operation Suspension Front Suspension Telescopic fork Shock Absorber Front Coil spring Air Oil damper Rear Coil spring Gas Oil damper Wheel Travel Front Wheel Travel 255 mm 10 0 in Rear Wheel Travel 235 mm 9 25 in Electrical Ignition System C D I Magneto Generator System Flywheel magneto Headlight T...

Page 133: ...rance 0 Small End Free Play F Limit YTZ250S 0 03 mm 0 0012 in Lines indicate straightedge measurement 68 8020 mm 2 68 gooos in 0 05 mm 0 002 in 0 01 mm 0 0004 in 68 goo mm 2 68 goo2 in 10 mm 0 394 in 0 060 0 065 mm 0 0024 0 0026 in 68 25 mm 2 69 in 68 50 mm 2 70 in 68 75 mm 2 71 in 69 00 mm 2 72 in 1 5 mm 0 059 in EX side Keystone B 1 2 mm 0 047 in T 2 8 mm 0 110 in Keystone B 1 2 mm 0 047 in T 2 ...

Page 134: ...1 mm 0 0004 in Shifter Shifting Type Guide bar Guide Bar Bending Limit 0 05 mm 0 0020 in Kick Starter Type Kick and mesh type Kick Clip Friction Force P 0 S 1 2 kg 1 76 2 65 Ib tJ Air Filter Oil Grade Oiled Filter Foam air filter oil or SAE10W30SE Carburetor Type Manufacturer VM32SS MIKUNI J D Mark lRX Main Jet M J 320 Main Air Jet M A J 02 0 Jet Needle clip Position J N 6FS 4 Needle Jet N J P 4 C...

Page 135: ...x 1 0 10 1 0 7 Cylinder Nut M10x 1 25 35 3 5 25 Stud M10x 1 25 13 1 3 10 Housing cover Flange bolt M 6x 1 0 10 1 0 7 Bolt M 6x 1 0 12 1 2 9 Intake manifold M 6x 1 0 12 1 2 9 Crankcase M 6x 1 0 12 1 2 9 Crankcase cover M 6x 1 0 12 1 2 9 Crankcase cover 1 M 6x 1 0 10 1 0 7 Bearing cover plate M 6x 1 0 10 1 0 7 Holder M 8x 1 25 16 1 6 12 Plate M 6x 1 0 10 1 0 7 Oil drain bolt M12x 1 5 20 2 0 14 Kicks...

Page 136: ... 0 3 93 in K2 5 88 N mm 0 60 kg mm 33 6 Ib in 100 255 mm 3 93 10 0 in Oil Capacity of 418 cm3 14 7 Imp oz 13 9 US oz Oil Level 180 mm 7 09 in From top of inner tube fully compressed without spring Oil Grade Yamaha fork oil 10wt or equivalent Enclosed Air Pressure Std okPa 0 kg cm2 0 psi max 58 8 kPa 0 6 kg cm2 8 53 psi Rear Suspension Shock Absorber Travel 92 mm 3 62 in Spring Free length 240 5 mm...

Page 137: ...35 mm 1 18 1 38 in Disc Brake Type Front Rear Single disc Outside Dia x Thickness 203 x 4 mm 8 x O 16 in Pad Thickness Limit Inner 6 0 mm 0 24 in 0 8 mm 0 03 in Outer 6 0 mm 0 24 in 0 8 mm 0 03 in Brake Fluid Type DOT 3 Master Cylinder Inside Dia 12 7 mm 0 49 in Caliper Cylinder Inside Dia 34 93 mm 1 37 in Brake lever Brake Pedal Brake Lever Free Play 0 5 1 0 mm 0 0197 0 0394 in at adjuster end Br...

Page 138: ...5 5 40 Upper engine bracket Frame M8 x 1 25 30 3 0 22 Lower engine mounting bolt M8 x 1 25 30 3 0 22 Frame Rear shock absorber M10x 1 25 32 3 2 23 Relay arm Rear shock absorber M10x 1 25 32 3 2 23 Relay arm Frame M10x 1 25 48 4 8 35 Swing arm Connecting rod M10x 1 25 48 4 8 35 Relay arm Connecting rod M10x 1 25 32 3 2 23 Disc brake Front Rear M8 x 1 25 28 2 8 20 Brake carliper Front Rear M10x 1 25...

Page 139: ...ITSUBISHI Ignition Coil ModelI Manufacturer F6T51173 MITSUBISHI Minimum Spark Gap 6 mm 0 24 in Primary Winding Resistance 0 29n 15 at 20 C 68 F Secondary Winding Resistance 4 0Kn 15 at 20 C 68 F Charging System Type Flywheel magneto F W Magneto Lighting Voltage 8 5 V or more at 1 500 r min 16 V or less at 8 000 r min Lighting Coil Resistance Color O 58n 10 at 20 C 68 F Y R B 15 10 I Q Ol lL C1l 0 ...

Page 140: ...d be at room temperatureo A Distance across flats B Outside thread diameter DEFINITION OF UNITS Unit Read Definition mm milimeter 10 3 meter cm centimeter 10 2 meter kg kilogram 1Q3gram N Newton 1 kg x m sec2 Nm Newton meter Nxm m kg Meter kilogram mxkg Pa Pascal N m2 N mm Newton per milimeter N mm L Liter cm3 Cubic centimeter r min Rotation per minute 6 16 A B General torque Nut Bolt specificatio...

Page 141: ...h mph 1 609 km hr km 0 6214 mi 1 609mi km m 3 281 ft ft 0 3048 m m 1 094 yd yd 0 9141 m cm 0 3937 in in 2 54 cm mm 0 03937 in in 25 4 mm cc cm3 0 03382 oz US liq oz US liq 29 57 cc cm3 cc cm3 0 06102 cu in cu in 16 387 cc cm3 lit liter 2 1134 pt US liq pt US liq 0 4732 lit liter lit liter 1 057 qt US liq qt US liq 0 9461 lit liter lit liter 0 2642 gal US liq gal US liq 3 785 lit liter kg mm 56 007...

Page 142: ...e on left side of head pipe and between handle crown and front panel then insert into steering shaft 6 18 Brake hose Throttle cable Fuel tank breather hose Route on right side of head pipe and between handle crown and front panel then insert into steering shaft ...

Page 143: ...ame Breather Left side of frame over radiator guard and pipe between engine mounting plates right side of throttle cable clamp outside of case breathed on carburetor joint recovery tank No excess slack in pipe between clamp and recovery tank is allowed Minimize the slack so that pipe is not too tight Recovery tank cap s tab should face toward front of the frame Carburetor overflow pipe Route betwe...

Page 144: ...gh clamp on rear part of air cleaner case and let it suspend Put couplers inside the side cover COl unit Wire harness 17 Voltage regurator Wire harness grounding lead Orange Secure to ignition coil Brake hose Clamp at two places on under bracket and outer tube Route inside the balance pipe and Clutch cable Pass through two guides on right side of frame and between frame and radiator then along one...

Page 145: ...ver tank pass through two guides on overflow pipe Fuel hose Pass through clamp on frame Breather and overflow pipe Pilot light Place on inner side of chamber stay and bring to radiator Radiator Headlight Wire harness The tab on clamp should face inner side of frame Front ____ Clip ends should face in this direction Section 8 8 ...

Page 146: ...endered inoperative by any person AMONG THOSE ACTS PRESUMED TO CONSTITUTE TAMPERING ARE THE ACTS LISTED BELOW These acts include tampering with the following systems i e modification removal etc Muffler Exhaust system Exhaust pipe Silencer Air cleaner case Intake system Air cleaner element Intake duct MAINTENANCE RECORD Copies of work orders and or receipts for parts you purchase and install will ...

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Yamaha YTZ250S 1986, Service Manual

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Summary of Contents for YTZ250S 1986

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