2004 Yamaha YZ250F(S) Owner's Service Manual (P/N 5XC-28199-30)

This Yamaha YZ250F(S) Owner's Service Manual (P/N 5XC-28199-30) covers operation, inspection, maintenance, tuning, and repair for the 2004 model and its listed market configurations.

Searchable PDF, Contents Links, and Page Count

Search and diagram detail: PDF text search is available. Language and chapter bookmarks lead to contents pages, whose linked entries open the individual sections. Small wiring and connector labels require zooming.

One printable, 658-page PDF contains English, French, German, and Italian text. The total includes the front cover, 22 introductory and contents pages, and one rear imprint page; the technical chapters span 634 pages across the four languages.

Engine, Chassis, Ignition, and Race Setup

These selected coverage highlights outline the main workshop areas rather than the complete contents. Other topics include cold and hot starting, break-in, cleaning, and storage.

• Engine internals: Camshaft timing, valve and spring inspection, cylinder and piston measurement, crankcase separation, and crankshaft installation.

• Clutch and transmission: Wet-clutch repair, kick-shaft and shift-shaft service, plus gearbox, shift-cam, and shift-fork inspection and assembly.

• Fuel and cooling: FCR-MX37 carburetor overhaul, accelerator-pump timing, radiator pressure testing, and water-pump shaft and seal service.

• Chassis repairs: Front-fork rebuilds, steering-bearing replacement, swingarm and linkage service, brake-caliper and master-cylinder repair, and brake bleeding.

• Ignition and TPS: Map-controlled CDI operation, no-spark troubleshooting, electrical component tests, throttle-position sensor replacement and adjustment, and wiring diagrams.

• Race setup: Carburetor symptom charts, sprocket selection, and front and rear suspension spring and damping settings, including European-market differences.

The repair sections suit mechanics familiar with precision measuring equipment and the specified special tools; Yamaha recommends dealer maintenance for the front fork.

Engine Inspection and Bottom-End Repair

Standard dimensions and wear limits let you compare measured components before deciding which parts require replacement. Camshaft, valve-spring, piston, and ring inspection data support overhaul assessment, while the Pad Selection Table supports valve-clearance adjustment.

Step-by-step procedures cover crankcase separation and crankshaft installation, with exploded views and job instruction charts showing component relationships and the extent of removal. The specified crankcase separator is YU-1135-A / 90890-01135.

Balancer timing marks and trochoid oil-pump clearance checks support bottom-end repair. The constant-mesh five-speed transmission section covers gear dogs, shafts, the shift cam, and shift forks. Cylinder-head installation includes staged tightening for the M9 bolts and M6 nuts.

Camshaft-cap cautions explain how uneven bolt tightening can damage the cylinder head, caps, and camshafts.

FCR-MX37 Carburetor Service and Tuning

The carburetor section details float-height inspection, jet cleaning, accelerator-pump inspection, and pump-timing adjustment. Tuning guidance connects atmospheric conditions and throttle response with main and pilot jets, needle diameter and clip position, and leak-jet selection.

Symptom-based setting charts support assessment of rich and lean running. Pilot-screw positions printed as examples are distinguished from the individually established factory setting.

Ignition Fault Tracing and Sensor Adjustment

The Ignition System inspection chart traces no-spark faults through connections, switches, coils, and the CDI magneto before CDI-unit replacement. TPS coverage includes resistance and supply-voltage checks, replacement, and output-voltage adjustment with tester-connection illustrations.

The Wiring Diagram and Cable Routing Diagram support connector and lead tracing. The 3-D Image Map of Ignition Timing explains the control principle; its illustrated characteristics are not an actual calibration map.

Fork, Linkage, and Rear-Shock Coverage

Front-fork procedures cover damper-rod removal, seal replacement, oil-level setting, and reassembly, using tools such as fork seal driver YM-01442 / 90890-01442. An assembly caution explains how a falling damper rod can damage the internal valve.

Swingarm instructions distinguish the polylube linkage bearings and give bearing, collar, and seal inspection and installation details. Suspension setting charts relate handling symptoms to checks and adjustments.

Rear-shock scope: Removal, spring and mounting-bearing replacement, preload, and damping adjustment are covered. The manual prohibits disassembly of the nitrogen-filled cylinder and reservoir; it does not provide an internal damper rebuild procedure.

Support the machine securely for chassis work and follow the manual's precautions for brake service, hot pressurized coolant, and the nitrogen-charged rear shock.

Selected Valve-Clearance and Electrical Test Data

For cold valve-clearance checks, the intake specification is 0.10–0.15 mm and the exhaust specification is 0.17–0.22 mm, with pad-selection tables for adjustment.

Electrical examples include ignition-coil secondary resistance of 4.6–6.8 kΩ at 20°C (68°F), measured between the orange lead and spark-plug terminal. TPS replacement and adjustment specifies 0.58–0.78 V output with the engine running after idle-speed adjustment.