2008 Yamaha YZ250F(X) Owner's Service Manual (P/N 5XC-28199-34-E0)

The Yamaha Owner's Service Manual for the 2008 YZ250F(X), also identified as YZ250FX, covers operation, maintenance, repair and tuning of the carbureted, kickstart motocross model. The English publication number is 5XC-28199-34-E0.

Text search, navigation and diagram detail: Main text is searchable, with embedded bookmarks for the contents, all seven chapters and the wiring diagram. The cover and some graphic table entries are outside the searchable text. Small wiring and connector labels are clear when enlarged.

• Engine repair: Cylinder-head, camshaft, valve and piston inspection, valve clearance adjustments, engine removal, crankcase separation, and crankshaft removal and installation.

• Transmission and clutch: Clutch disassembly and inspection, transmission service, shift cam and shift fork checks, and kick shaft and shift shaft repair.

• Carburetor service: FCR-MX37 disassembly, float-height inspection, accelerator-pump timing adjustment, hot-start components, and carburetor tuning for different throttle openings.

• Cooling and lubrication: Radiator and cooling-system pressure tests, water-pump inspection, oil filter service, oil-pump clearance checks, and lubrication diagrams.

• Brakes and steering: Hydraulic brake bleeding, caliper and master-cylinder repair, brake pad replacement, and steering head bearing inspection and adjustment.

• Suspension and chassis: Front fork overhauls, rear Monocross spring and bearing service, swingarm and linkage inspection, and wheel-bearing replacement.

• Electrical troubleshooting: Ignition-system fault isolation, CDI magneto and ignition-coil checks, throttle position sensor testing and adjustment, and wiring diagrams.

The repair sections suit mechanics equipped for internal engine work and electrical testing; owners also get operating instructions and routine-maintenance guidance.

Engine Repair and Drivetrain Inspection

The liquid-cooled four-stroke DOHC engine sections cover camshaft-to-cap clearance checks, decompression-system inspection, valve-guide replacement and valve-seat work. Separate intake and exhaust pad selection tables support valve clearance adjustments.

Clutch coverage distinguishes the first clutch plate from the remaining plates and identifies the cushion spring and seat plate. Transmission procedures address gear dogs, shift fork grooves, shift cam inspection and assembly checks; the balancer section includes shaft and gear alignment.

The camshaft section warns that uneven cap-bolt tightening can damage the cylinder head, camshaft caps and camshafts.

FCR-MX37 Carburetor Repair and Tuning

Float and needle-valve checks sit alongside accelerator-pump diaphragm inspection and timing adjustment. The tuning chapter relates main jets, pilot jets, jet needles and leak jets to throttle response, atmospheric conditions and mixture symptoms.

The symptom-based carburetor setting chart helps distinguish jetting changes from checks for restricted fuel flow, a dirty air filter or accelerator-pump trouble. Optional jet and needle part numbers are listed.

Cooling, Lubrication and Service Specifications

Cooling coverage includes radiator-cap opening-pressure checks, system leak testing and water-pump shaft, bearing and seal inspection. Dry-sump lubrication coverage extends to the oil tank, strainers, delivery pipes and oil-pump rotors.

Component-specific torque tables, oil capacities, cylinder-head warpage limits, spark-plug specifications and electrical test values accompany the repair procedures. Exploded assembly views and job instruction charts identify parts and required operations; cable routing diagrams show hose, lead and control-cable placement.

Brakes, Steering and Suspension

Chassis procedures cover brake piston and seal inspection, steering bearing replacement, and swingarm relay-arm and connecting-rod bearings. Suspension setting charts relate handling symptoms to damping, spring selection and fork oil quantity, with separate European baseline settings where applicable. Tire-pressure guidance and sprocket selection are also covered.

The front fork section details damper bleeding and seal replacement, and warns that dropping the damper assembly into the inner tube can damage its internal valve. Listed tools include the cap bolt wrench YM-01500 / 90890-01500 and fork seal driver YM-A0948 / 90890-01502.

Yamaha recommends dealer maintenance for the front fork. Rear shock coverage includes removal, spring and bearing service, and adjustment; it does not provide an internal damper rebuild procedure. The handling notes address the hazards of the nitrogen-charged shock cylinder and reservoir.

Ignition Diagnosis and Throttle Position Sensor Testing

The ignition inspection chart links no-spark symptoms to checks of the stop switch, coils, connections and neutral switch, helping isolate a fault before CDI replacement. Throttle position sensor procedures cover resistance, variable resistance, input voltage and output-voltage adjustment, with connector illustrations.

Specifications distinguish the 5XC-L0 CDI unit for USA/Canada from the 5XC-M0 unit for Europe, Australia, New Zealand and South Africa. Electrical tests reference the pocket tester YU-3112-C / 90890-03112 and dynamic spark tester YM-34487.

English PDF and Included Pages

One printable English-language PDF with 186 pages total: one cover, three introductory pages, two contents pages and 180 numbered pages across seven chapters. All preliminary pages are included in that total.