Eng | Yamaha WR250FM specification

CARBURETOR

ENG

Extent of removal				Order	Part name	Q’ty	Remarks

				F	Float pin	1
				F	Float pin	1
				G	Float	1
				H	Needle valve	1
				I	Main jet	1
				J	Needle jet	1
				K	Spacer	1
	1			L	Pilot jet	1
				M	Starter jet	1
				N	Push rod	1	Pull the push rod.
				O	Throttle shaft assembly	1
				P	Push rod link lever assembly	1
				Q	Pilot air jet	1
				R	Cold starter plunger	1
				R	Cold starter plunger	1

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Yamaha WR250FM service manual Eng

Contents

WR250FR Page WR250FR Introduction Page Always Wear Protective Apparel Always Maintain Your Machine in Proper Working Order Gasoline can Cause Injury Park the Machine Carefully Turn OFF the EngineProperly Secure the Machine Before Transporting IT M. Machine Weights Weights of machines without fuel Particularly Important Information Finding the Required HOW to Read Descriptions Manual Format GEN Spec Info Insp ENG ADJ Memo Index Chapter Regular Inspection Adjustments SEAT, Fuel Tank Valves and Valve SpringsRight Crankcase Cover AC Magneto Electrical Components Throttle Position Sensor Description Info Description Machine Identification Vehicle Identification NumberEngine Serial Number Model Label Preparation for Removal and Disassembly Important Information ALL Replacement Parts Lock WASHERS/PLATES and Cotter PinsGASKETS, OIL Seals and O-RINGS Bearings and OIL Seals Circlips Checking of Connection Special Tools Part number Tool name/How to use Illustration ACC-QUICK-GS-KT Main Switch Main switch indicator lightEngine Stop Switch Start Switch Clutch Lever Shift PedalKickstarter Crank Throttle Grip Rear Brake Pedal Fuel CockCold Starter Knob HOT Starter Lever Light Switch Valve JointSpark Plug Wrench Nipple Wrench Fuel AIR Filter Maintenance Starting and BREAK-INStarting a Cold Engine Do not warm up the engine for extended periods of time Starting a Warm Engine Restarting an engine after a fallEngine fails to start BREAK-IN Procedures Cylinder and CrankshaftAbout one hour of break-in operation is necessary PISTON, RING, VALVES, Camshafts and Gears TORQUE-CHECK Points Cleaning and Storage Cleaning Storage General Specifications 5UM4 CDN, AUS, NZ, ZA FCR-MX37 CDI Maintenance Specifications Engine Head diameter Face width Seat width Margin thickness 1.6 mm Spec USA EUROPE, CDN ZA, AUS, NZ Spec Part to be tightened Thread size ’ty Tightening torque Silencer Chassis USA, CDN Europe AUS, NZ, ZA USA, CDN, ZA EUROPE, AUS, NZ Upper bracket and outer tube Nipple spoke Rear wheel sprocket M4 ⋅ Electrical 5UL-00/DENSO ACM33221 M06/MATSUSHITA General Torque Specifications Definition of UnitsTorque Mkg Ftlb 10 mm 12 mm 14 mm 17 mm 19 mm 22 mm 16 mm 130 Cable Routing Diagram Spec Spec Spec Spec Spec Spec Spec Spec Maintenance Intervals Insp ADJ Maintenance Intervals ADJ Cooling System Marked For USA PRE-OPERATION Inspection and Maintenance General Inspection and Maintenance Coolant Replacement Do not remove the radiator cap when the engine is hotEngine Coolant Level Inspection Coolant Replacement Fill Radiator Engine To specified level Radiator CAP Inspection Radiator CAP Opening Pressure Inspection Clutch Adjustment Radiator cap opening pressure KPa 1.1 kg/cm2, 15.6 psiCooling System Inspection Standard pressure KPa 1.8 kg/cm2, 25.6 psi Throttle Cable Adjustment Clutch lever free play adjustment stepsThrottle Cable Adjustment Throttle grip free play adjustment steps HOT Starter Lever Adjustment Hot starter lever free play adjustment stepsThrottle Lubrication Hot starter lever free play a 3 ~ 6 mm 0.12 ~ 0.24 AIR Filter Cleaning AIR Filter Cleaning Insp ADJ Engine OIL Level Inspection Engine OIL Level Inspection Engine OIL Replacement Engine OIL ReplacementAPI Standard Replacement steps Oil filter element cover 10 Nm 1.0 m kg, 7.2 ft lb Install Copper washer 1 New Oil strainer frame Pilot Screw Adjustment OIL Pressure Inspection Engine Idling Speed Adjustment Valve Clearance Inspection and Adjustment Valve Clearance Inspection and Adjustment Pad range Pad Availability Increments 20 mm Mm increments40 mm Last digit of pad Rounded value Example Intake Exhaust Spark Arrester Cleaning For USA CHASSIS/BRAKE System AIR Bleeding ChassisBrake System AIR Bleeding Front Brake Adjustment Front Brake AdjustmentBrake lever position adjustment steps Rear Brake Adjustment Front Brake PAD Inspection and Replacement Front Brake PAD Inspection and Replacement Do not reuse the drained brake fluidBleed screw Nm 0.6 m kg, 4.3 ft lb Rear Brake PAD Inspection and Replacement Rear Brake PAD Inspection and ReplacementPad pin plug Nm 0.3 m kg, 2.2 ft lb Brake pad thickness Mm 0.25 in Limit 1.0 mm 0.04 Pad pin 18 Nm 1.8 m kg, 13 ft lb Rear Brake PAD Insulator Inspection Brake Fluid Level Inspection Sprockets INSPECTION/DRIVE Chain Inspection Sprockets InspectionDrive Chain Inspection Drive chain length 10 links Limit 150.1 mm 5.91 Drive Chain Inspection Drive Chain Slack Adjustment Drive Chain Slack AdjustmentDrive chain slack adjustment steps Drive chain slack 40 ~ 50 mm 1.6 ~ 2.0 Front Fork OIL Seal and Dust Seal Cleaning Axle nut 125 Nm 12.5 m kg, 90 ft lbLocknut 16 Nm 1.6 m kg, 11 ft lb Front Fork Inspection Front Fork Rebound Damping Force Adjustment Front Fork Internal Pressure Relieving Front Fork Compression Damping Force Adjustment Standard position 9 clicks out Clicks out Rear Shock Absorber Inspection Standard position 14 clicks out Clicks outRear Shock Absorber Inspection Rear Shock Absorber Spring Preload Adjustment Standard position About 7 clicks out About 10 clicks out Rear Shock Absorber LOW Compression Damping Force Adjustment Standard position About 9 clicks out About 10 clicks out Standard position About 1-1/4 turns out Tire Pressure Check Standard tire pressure KPa 1.0 kgf/cm2, 15 psiSpokes Inspection and Tightening Wheel Inspection Steering Head Inspection and Adjustment Steering Head Inspection AdjustmentSteering ring nut adjustment steps Steering nut wrench YU-33975/90890-01403 Steering nut wrench 38 Nm 3.8 m kg, 27 ft lbAvoid over-tightening Lubrication Lubrication Electrical Spark Plug InspectionSpark plug gap ~ 0.8 mm 0.028 ~ 0.031 Ignition Timing Check Ignition Timing Check Battery Inspection and Charging Battery Inspection and ChargingKeep Batteries and Electrolyte OUT of Reach of Children First AID in Case of Bodily Contact External Remove Battery band Measurement steps Example Charge Battery Charging method using a variable voltage charger Charging method using a constant voltage charger Battery REPLACEMENT/FUSE Inspection Battery ReplacementFirst, connect the positive lead 1, then the negative lead Recommended lubricant Lithium soap base grease Fuse Inspection Pocket tester YU-3112-C/90890-03112Items Amperage rating ’ty Adjusting the Headlight Beams Adjusting stepsReplacing the Headlight Bulbs SEAT, Fuel Tank and Side Covers SEAT, Fuel Tank and Side Covers Removal Removal Points Side cover Exhaust Pipe and Silencer Exhaust Pipe Silencer Removal Assembly and Installation Silencer and exhaust pipe Silencer and exhaust pipe Radiator Radiator Removal Assembly and Installation Radiator Handling NoteRadiator Install Right radiator Bolt right radiator Carburetor Carburetor Removal Carburetor Disassembly Carburetor Disassembly ENG Pilot screw Carburetor Needle valve Throttle valveJet needle Standard clip position No.4 Groove Float height Mm 0.31 Measurement and adjustment steps Float heightFloat Assembly and Installation Carburetor Starter plungerAccelerator pump Air cut valve ENG ENG Pilot screw Turns out example 8 turns out ENG Accelerator pump timing adjustment Adjustment steps Carburetor installationThrottle valve height Mm 0.06 Carburetor ENG Carburetor ENG Camshafts Cylinder Head CoverCylinder Head Cover Removal Camshafts Camshafts Removal Camshaft Runout camshaft Less than 0.03 mm 0.0012 Bolt camshaft cap 10 Nm 1.0 m kg, 7.2 ft lb Assembly and Installation Camshaft Installation stepsDecompression system Timing chain tensioner CA U TI O N Camshafts ENG Bolt timing chain tensionerTensioner cap bolt Quick gasket ACC-QUICK-GS-KT Yamaha Bond No Cylinder Head Cylinder Head Removal Cylinder head Assembly and Installation Cylinder head Valves and Valve Springs Valves and Valve Springs Removal Valve lifter and valve cotter Valve spring compressor YM-4019/90890-04019 Valve Margin thickness Intake Mm 0.0315 in Exhaust Mm 0.0276 Runout limit 01 mm 0.0004 Lapping steps Valve spring Assembly and Installation Valve and valve spring Combination of cylinder head and valve lifterCombination Cylinder head mark Valve lifter mark b Color Yellow Valve spring compressor YM-4019/90890-04019 Cylinder and Piston Cylinder and Piston Removal Piston and piston ring Piston pin puller set YU-1304/90890-01304Do not use a hammer to drive the piston pin out Cylinder and piston Cylinder bore C 77.00 ~ 77.01 mm 0315 ~ 3.0319 05 mm 0.0022nd step Piston size P Piston ring Side clearanceLimit End gap Piston pin Inside diameter piston 16.002 ~ 16.013 mm 0.6300 ~ 0.6304 Cylinder Install Bolt cylinder Clutch Clutch Removal ENG Clutch housing and boss Clutch bossClutch holding tool YM-91042/90890-04086 Primary driven gear Friction plate Clutch plateWarp limit Mm 0.004 Push lever shaft Push rod Assembly and Installation Push lever shaft Clutch ENG Install Push rod 2 Ball Push rod 1 OIL Filter ELEMENT, Water Pump and Right Crankcase Cover ENG Impeller shaft Oil sealOil delivery pipe Assembly and Installation Oil seal Impeller shaft gearBearing Right crankcase cover Kickstarter crank Water pump housing Oil filter element Balancer Balancer Removal Balancer shaft drive gear and balancer shaft driven gear Balancer shaft Primary drive gear Nut primary drive gear OIL Pump Removal and DIS Assembly OIL Pump ENG Oil pump Assembly and Installation Oil pump Bolt oil pump assembly L = 30 mm 1.18 Kick Shaft and Shift Shaft Kick Shaft and Shift Shaft Removal ENG Kick shaft assembly Shift guide and shift lever assemblySegment Kick shaft and ratchet wheel Assembly and Installation Shift shaftStopper lever Install Torsion spring Stopper lever Bolt stopper lever Kick shaft assembly Kick idle gear AC Magneto and Starter Clutch AC Magneto and Stator Removal ENG Rotor Rotor puller YM-04141/90890-04141AC magneto Woodruff key Assembly and Installation AC magneto and starter clutch Install Holder Bolt Plain washer rotor Nut rotor Bolt engine guard rear Engine Removal Engine Removal ENG Drive sprocket Engine removal Assembly and Installation Engine installation Brake pedal Oil hose and neutral switch Nm 0.4 m · kg, 2.9 ft · lb Crankcase and Crankshaft Crankcase and Crank Shaft Removal ENG Crankcase Bearing Crankcase Bearing Removal Crankcase Separation steps Crankshaft Crankcase separating tool YU-1135-A/90890-01135Timing chain and timing chain guide Dial gauge and stand YU-3097/90890-01252 Standard Limit Assembly and Installation Crankcase bearing Do not use a hammer to drive in the crank- shaft Apply Sealant On the right crankcase Tighten Hose guide Clutch cable holder Bolt crankcase TRANSMISSION, Shift CAM and Shift Fork TRANSMISSION, Shift CAM Shift Fork Removal Transmission Gears Assembly and Installation Transmission Shift fork, shift cam and segment ENG ENG Front Wheel and Rear Wheel Chas Front Wheel and Rear WheelFront Wheel Front Wheel Removal Rear Wheel Rear Wheel Removal Rear wheel Wheel bearing if necessaryWheel Wheel axle Wheel axle bending limit 0.5 mm 0.020Do not attempt to straighten a bent axle Brake disc Front wheel 105 Nm 10.5 m · kg, 75 ft · lb Tighten Bolt axle holder Install Trip meter cable 50 Nm 5.0 m · kg, 36 ft · lb 125 Nm 12.5 m · kg, 90 ft · lb Front Brake and Rear Brake Chas Front Brake and Rear BrakeFront Brake Front Brake Removal Rear Brake Rear Brake Removal Brake Caliper Disassembly Brake Caliper Disassem BLY Brake Master Cylinder Disassembly Brake Master Cylinder Disassembly Brake fluid Brake caliper piston seal kit Brake master cylinderUse only new brake fluid Brake caliper Brake hose Always use new piston seals and dust seals Front brake caliper Rear brake caliper Brake master cylinder kit Front brake master cylinder Rear brake master cylinder Front brake hose CAU TI on Always use new copper washers CAU T ION Install rear brake only Protector Bolt protector Front Fork Chas Front ForkFront Fork Removal Front Fork Disassembly Front Fork Disassembly Front fork cap bolt Inner tube Take care not to scratch the inner tubeOil seal removal steps Damper rod Base valve Fork springFork spring free length 460 mm 18.1 in Limit 455 mm 17.9 Inner tube bending limit 0.2 mm 0.008 Assembly and Installation Front fork assembly Front Fork Chas Fork seal driver YM-01442/90890-01442 Front Fork Chas Front Fork Chas Front Fork Chas Installation Front fork top end standard a 5 mm 0.20 10 mm 0.39 Tighten Pinch bolt upper bracket Handlebar Chas HandlebarHandlebar Removal Grip Handlebar Assembly and Installation Handlebar Install Grip cap cover Cover throttle cable cap Hot starter lever holder Bolt hot starter lever holder Handlebar Chas Steering Chas SteeringSteering Removal Steering Chas Steering ring nut Take care not to damage the steering shaft threadBall race Steering stem Bearing and ball race Lower bracket Install Washer Steering ring nut Install Washer Steering stem nut Install Trip meter Bolt trip meter Swingarm Chas SwingarmSwingarm Removal Swingarm Disassembly Swingarm Disassembly Swingarm Relay arm Connecting rod Bearing and oil seal Installed depth of bearings a 5 mm 0.20 Installed depth of bearings a 5 mm 0.20 Swingarm 80 Nm 8.0 m · kg, 58 ft · lb Tighten Nut relay arm Bolt drive chain support cover = 10 mm 0.39 Rear Shock Absorber Chas Rear Shock AbsorberRear Shock Absorber Removal Starting circuit cut-off relay coupler Handling Note Rear shock absorber Install Spring Upper spring guide Lower spring guide Tighten Adjuster Spring length installed a Bolt rear frame lower Rear Shock Absorber Chas Electrical Components and Wiring Diagram Wiring DiagramColor Code MAP-CONTROLLED CDI Unit Function of Component Ignition System Inspection Steps Engine Stop Switch Inspection Ignition System Elec +Spark GAP Test COUPLERS, Leads and Ignition Coil Connection Inspection Main Switch Inspection Battery + lead → Red/Black lead 1 Battery lead → Black leadTester + lead → Red lead Tester lead → Brown lead Ignition Coil Inspection Resistance Position 08 ~ 0.10 Ω at 20 C 68 FResistance Position ~ 6.8 kΩ at Neutral Switch Inspection AC Magneto InspectionResistance Position 248 ~ 372 Ω at 20 C 68 F Tester + lead → Sky blue lead 1 Tester lead → Ground Electric Starting System Starting Circuit CUT-OFF System Operation Inspection Steps Battery To batteryCouplers and Leads Connection Inspection Starter Motor Operation Clutch Switch Inspection Starter Relay InspectionPull Free Start Switch Inspection Electric Starting System Elec +Diode Inspection Starter Motor Starter Motor RemovalStarter Motor Disassem BLY Inspection and Repair Min. commutator diameter 16.6 mm 0.65Mica undercut 1.5 mm 0.06 Assembly Be careful not to damage the brush during installationMin. brush length Mm 0.14 New Charging System Charging Voltage Inspection Tester + lead → Red lead Tester lead → Black leadVoltage Position 14.1 ~ 14.9 V at DCV-20 000 r/min Resistance Position 288 ~ 0.432 Ω at 20 C 68 F Throttle Position Sensor System Throttle Position Sensor System Elec + Throttle Position Sensor Coil Inspection~ 6 kΩ at Throttle Position Sensor Replacement and Adjustment Coil variable resistanceAt 20 C 68 F Tester + lead → Yellow lead Tester lead → Black lead Throttle position Tester selector58 ~ 0.78 DCV Throttle Position Sensor Input Voltage Inspection ~ 6 DCV-20 Lighting System Light Switch Inspection OFFRECTIFIER/REGULATOR Inspection Setting Carburetor setting Settings Effects of the setting parts on the throttle valve opening Main systemPilot system Main jet adjustment Standard main jet #185 #172Effects of changing the main jet reference Setting T U N Effects of adjusting the pilot jet reference Jet needle groove position adjustment Jet needle adjustment Standard jet needleObdvs Obelp Effects of changing the jet needle reference Leak jet adjustment accelerator pump adjustment Standard leak jet #90 Relationship with throttle opening STD Examples of carburetor setting depending on symptom Selection of the secondary reduction ratio Sprocket Standard secondary reduction ratio 52/13 9383B-13218 5GS-25448-50Sprocket 5NY-25448-00 Front fork setting Change in level and characteristics of fork oil Spring preload adjustment Setting of spring after replacement Part Number SpringMark Rate Rear suspension setting Choosing set lengthStandard figure 90 ~ 100 mm 3.5 ~ 3.9 Setting of spring after replacement Setting Rear shock absorber setting parts Adjustment bSpring Free Extent Suspension setting One passenger is astride seat Printed on Recycled Paper Shingai Iwata Shizuoka Japan