Yamaha YZ250 2001–2006 Service & Parts Manual Set (P/N 5MW-28199-30)

Use the matching annual edition to check regional carburetor and electrical data, cable routing, specifications, and repair procedures. The parts catalogs complement the service instructions with exploded assembly references.

Parts catalog limits: The two catalog PDFs contain exploded illustrations and reference callouts, without itemized replacement-part-number lists. Catalogs for the other model years are outside this set. The 2005 catalog also references Assembly Manual LIT-11666-18-33, which is not included.

Text Search, Bookmarks, and Wiring Detail

Search and navigation: The seven service manuals support text search, apart from the warning page in the U.S. 2005 PDF; the parts catalogs do not. Bookmarks in the 2001–2005 annual files mainly open contents pages. The 2006 edition adds detailed section links, with some inactive parent items; the U.S. 2005 edition has direct section bookmarks. Catalog bookmarks use image filenames. Small wiring labels are readable when enlarged.

The ZIP contains nine printable PDFs totaling 3,874 pages. The six annual manuals combine English, French, German, and Italian; the additional U.S. manual is in English. All covers and introductory material, 17 memo pages, and six blank pages are already included in that total.

Two-Stroke Engine Repair, Chassis Service, and Race Setup

These selected coverage highlights are not a complete contents list. Further topics include starting and break-in, cleaning, and storage.

• Engine and transmission: Step-by-step procedures for top-end repair, clutch and primary-drive service, crankcase separation, crankshaft work, and transmission/shift-mechanism disassembly.

• Fuel and cooling: Carburetor and reed-valve inspection, radiator service, water-pump repair, and carburetor-setting information for changing operating conditions.

• Brakes and wheels: Master-cylinder and caliper service, hydraulic disc-brake bleeding, wheel-bearing and spoke checks, and drive-chain alignment.

• Suspension and steering: Front-fork disassembly and seal/oil service, steering-head work, swingarm/linkage bearings, and rear-shock spring and bearing procedures.

• Electrical diagnosis: Wiring diagrams and factory inspection charts for ignition, solenoid-valve operation, and throttle position sensor testing, replacement, and adjustment.

• Track setup and service references: Symptom-based carburetor and suspension tuning, sprocket selection, maintenance schedules, torque tables, and component wear limits.

These manuals are suited to mechanics comfortable with internal engine work and electrical testing using the specified measuring equipment and special tools.

Internal Engine Inspection and Repair

Top-end sections cover cylinder measurement, piston inspection, power-valve service, and reassembly. The cylinder instructions explicitly rule out reboring.

Separate procedures address the kickstarter and shift shaft, YPVS governor, water-pump impeller shaft and seals, and flywheel/CDI magneto removal. Transmission coverage extends to shift-cam and shift-fork inspection, reassembly, and operating checks.

Yamaha’s cautions address damaged crankcase sealing faces from forced separation or hammer blows, plus damage from hammering the crankshaft or piston pin; the procedures specify dedicated separating, pulling, and installing tools.

Fork Service and Rear-Shock Scope

The 2006 front-fork section includes base-valve work and damper-assembly bleeding, supported by exploded views. Fork-seal instructions warn that scratches on the inner tube can damage the seal and cause leakage.

Rear-shock coverage includes removal, spring and bearing work, inspection, adjustment, and installation. Internal disassembly of the nitrogen-filled cylinder and reservoir is outside the described service scope.

Brake, ignition, crankcase, and suspension repair should follow the correct year/model section and Yamaha safety notes before the machine returns to closed-course competition use.

Ignition, Solenoid, and TPS Fault Isolation

The no-spark inspection chart covers the spark-gap test, connections, engine-stop switch, ignition-coil windings, plug cap, CDI magneto pickup/source coils, and CDI unit. The 2006 edition adds the regional neutral-switch check, except for U.S. and Canadian models.

Separate inspection charts address solenoid-valve operation and coil testing. TPS coverage includes fixed and variable resistance checks, replacement, adjustment, and input-voltage testing.

Jetting, Suspension Settings, and Workshop References

Track-side tuning explains how temperature, humidity, and altitude affect mixture. Throttle-opening charts relate the pilot circuit, needle, throttle valve, power jet, and main jet to operating range; symptom tables support carburetor-setting decisions.

Chassis tuning covers final-drive ratio and sprocket selection, tire-pressure adjustment, front-fork oil/spring/damping setup, rear-spring preload, and compression/rebound adjustment. Suspension symptom/adjustment charts connect handling complaints with the relevant settings.

Reference material includes pre-operation checks, torque-check points, component torque tables, capacities, wear and runout limits, clearances, electrical test values, and jetting data. Cable Routing Diagrams and the Electrical Components and Wiring Diagram support hose, cable, and electrical work.

Special-Tool Identification

Tool tables cross-reference North American YM/YU numbers with international 90890 numbers. Engine examples include the YU-1135-A / 90890-01135 crankcase separating tool, YM-1189 / 90890-01189 flywheel puller, and YU-1304 / 90890-01304 piston-pin puller.

Other references include the YU-24460-01 / 90890-01325 radiator-cap tester, YM-91042 / 90890-04086 clutch holding tool, and YM-34487 / 90890-06754 dynamic spark tester/ignition checker.

A Preview of Piston and Ring Inspection Limits

For the 2005 YZ250T1, the U.S. manual lists standard piston-to-cylinder clearance at 0.045–0.050 mm, with a 0.1 mm limit. The same section includes A–D piston/cylinder matching charts.

Installed piston-ring end gap is specified at 0.40–0.55 mm, with a 0.95 mm limit. The top-end chapter explains the measurement checks used to compare the components with these standard and limit values.