2000 Yamaha YZ250(M)/LC, YZ250LC, YZ250M1 Owner's Service Manual (P/N 90890-01135)

The 2000 Yamaha YZ250 Owner’s Service Manual covers factory maintenance, repair, and race setup for the liquid-cooled two-stroke motocross bike. The repair sections are written for mechanics, while the owner material explains operation, basic maintenance, and inspection. Whether you are rebuilding the top end or dialing in the suspension for race day, the manual provides assembly-specific procedures and reference data.

Always review the safety guidelines before tearing down major components, especially the warnings for pressurized coolant and the nitrogen-charged rear shock.

Core Repair Coverage

• Cylinder head, cylinder, piston, and YPVS: Top-end disassembly, wear inspection, piston-to-cylinder matching, power-valve assembly, and governor service.
• Clutch and primary gear service: Friction-plate and clutch-plate inspection, clutch release mechanism repair, and removal and installation of the primary drive and driven gears.
• Crankcase separation and crankshaft installation procedures extend to internal transmission repair, including gear inspection, shift-cam and shift-fork checks, and assembled shifting checks.
• Keihin PWK38S carburetor and reed valve: Disassembly, jet and needle inspection, float-height adjustment, reed-valve checks, and reassembly.
• Cooling-system coverage includes radiator-cap and system pressure tests, radiator removal, and water-pump impeller-shaft, bearing, and oil-seal service.
• Front and rear brake procedures cover caliper and master-cylinder disassembly, seal replacement, and air bleeding. Chassis work also includes fork overhaul, steering bearings, and swingarm linkage service.
• Electrical diagnosis combines a wiring diagram with separate ignition, solenoid-valve, and TPS (throttle position sensor) inspection flowcharts, plus TPS replacement and adjustment procedures.

Model Coverage and Regional Differences

This 568-page PDF contains English, French, German, and Italian text within one multilingual publication. It covers YZ250LC for Europe, YZ250M1 for the USA, and YZ250(M) for Canada, Australia, New Zealand, and South Africa.

The model-code assignments are 5HC1 for the USA, Canada, and South Africa; 5HC2 for Europe; and 5HC4 for Australia and New Zealand. Identification instructions locate the frame or vehicle identification number, engine serial number, and model label.

Regional distinctions matter when selecting setup data. The specifications identify different European carburetor settings and suspension specifications. The tuning section distinguishes equal-pitch and unequal-pitch springs, with European standard selections identified in the spring tables.

Document Scope & Technical Data

The specifications chapter provides component-specific torque tables, fluid capacities, clearances, wear limits, and electrical test values. Transmission oil data distinguish a periodic oil change from the total fill. Ignition references cover the ignition coil, both CDI magneto source coils, and the pickup coil; sensor checks include variable resistance and input voltage.

For top-end repair, the piston-and-cylinder matching chart ties cylinder identification marks to piston size groups and color markings. The cylinder section explicitly prohibits reboring. Assembly notes also flag a specific YPVS risk: push-rod fastener work without the specified set pin can damage power-valve components.

Cable-routing diagrams show hose and lead placement around the frame, radiators, and controls. Exploded views for the water pump and front fork accompany parts-and-job charts. The fork repair notes explain that a dropped damper rod can damage the internal valve during assembly.

Special-tool references include the crankcase separating tool YU-01135-A / 90890-01135 and piston pin puller YU-01304 / 90890-01304. The tool section distinguishes US/Canadian tool numbers from those used in other markets.

Race Tuning and Suspension Service Limits

Carburetor tuning includes a throttle-opening chart showing where the different metering components act, weather and track-condition examples, and symptom-based setting tables. Optional jets, needles, sprockets, and suspension springs are listed with part numbers.

Suspension guidance covers rider sag, spring selection, fork oil-level effects, rebound damping, and separate low- and high-compression adjustments at the rear shock. Front-fork and rear-shock setting charts relate handling symptoms to inspection and adjustment areas.

Yamaha recommends dealer maintenance for the front fork. Rear-shock coverage includes removal, spring and bearing replacement, and external adjustment; it does not provide an internal damper or nitrogen-reservoir rebuild procedure.

This is the 1st Edition, June 1999, bearing cover code 5HC-28199-30.