2005 Yamaha YZ250(V) Owner's Service Manual (P/N 1P8-28199-31)

This 596-page multilingual PDF contains Yamaha’s Owner’s Service Manual P/N 1P8-28199-31 for the YZ250(V), 1st Edition, May 2005. Coverage is identified by market and model code: YZ250V / 1P85 for the USA and Canada; YZ250 / 1P86 for Europe; and YZ250V / 1P88 for Australia, New Zealand, and South Africa. The publication includes English, French, German, and Italian text. Yamaha specifies this machine for single-rider competition on closed courses, not public-road use. Although titled an Owner’s Service Manual, its sequential, exploded-view format reaches well into internal repair work. It is suited to experienced owners and mechanics familiar with two-stroke engine service and equipped with the specified pullers, holding tools, testers, and suspension tools.

• Top-end and induction work: Covers PWK38S carburetor removal, disassembly, inspection, reassembly, and setting; reed-valve service; and cylinder-head, cylinder, piston, piston-ring, and power-valve procedures.
• Bottom-end and transmission repair: Details complete engine removal, crankcase separation, crankshaft inspection and installation, clutch and primary-drive service, kick and shift mechanisms, and the constant-mesh five-speed transmission with its shift cam and forks.
• Cooling and exhaust service: Includes radiator removal and pressure testing, coolant-system inspection, water-pump disassembly and reassembly, exhaust-pipe service, muffler inspection, and silencer-fiber replacement.
• Chassis overhaul coverage: Walks through wheel and bearing work, hydraulic brake caliper and master-cylinder service, system bleeding, front-fork disassembly and assembly, steering-head service, swingarm and linkage work, plus rear-shock removal and spring setup.
• Electrical fault finding: Provides the complete wiring diagram, ignition-system fault isolation, spark-gap and coil testing, source- and pickup-coil checks, solenoid-valve diagnosis, and TPS resistance, alignment, output, and input-voltage inspections.
• Specification and tuning support: Supplies component torque tables, capacities, wear and runout limits, clearances, electrical test values, market-specific carburetor data, gearing choices, and front- and rear-suspension setup charts.

Routine Service and Repair Depth

The regular inspection section covers the race-use maintenance schedule and pre-operation checks, along with coolant-cap testing, clutch and throttle adjustment, air-filter cleaning, transmission-oil service, pilot-air and idle-speed settings, brake-pad and fluid checks, chain and sprocket inspection, spoke and wheel checks, steering-head adjustment, spark-plug inspection, and ignition-timing verification.

Suspension information goes beyond external clicker settings. The fork chapter covers removal, internal disassembly, seal and bushing inspection, damper bleeding, oil-level setup, and final installation. The rear-shock chapter covers removal, spring and bearing work, inspection, and installation, but not internal disassembly of the nitrogen-charged cylinder or reservoir. Yamaha reserves shock-disposal depressurization for dealers.

Market-Specific Data and Illustrated References

Regional tables distinguish carburetor calibration, cylinder-head specifications, chassis geometry, and suspension data. The neutral-switch circuit and its routing apply outside the USA and Canada, another reason to match the model code and model label before selecting parts or repair data.

Useful named references include the Electrical Components and Wiring Diagram, the multi-page Cable Routing Diagram and brake-hose routing view, the Ignition System inspection chart, the Relationship with Throttle Opening carburetor chart, Examples of Carburetor Setting Depending on Symptom, and the front- and rear-Suspension Setting charts. Exploded assembly views and work-order tables open each major removal and disassembly section.

Special Tools and Component-Specific Cautions

The tool list gives both North American and international numbers. Examples include the crankcase separator YU-1135-A / 90890-01135, flywheel puller YM-1189 / 90890-01189, crankshaft installation tools YU-90050 and YU-90063 / 90890-01274, -01275, and -01278, fork cap tools YM-01500 and YM-01501 / 90890-01500 and -01501, and Yamaha pocket tester YU-3112-C / 90890-03112.

The manual flags two repair traps that matter during teardown. The YPVS push-rod bolt must be restrained with the supplied set pin; omitting it can damage the power-valve components. During fork repair, the air chambers must be fully relieved before the base valves are removed, and the damper-rod locknut must remain in place or the rod can drop into the damper assembly. Factory warnings also address hot coolant, brake-fluid handling, fork contamination, and the high-pressure nitrogen rear shock.