Yamaha YFM225 Service & Factory Manual | 1986-1988 ATV

• Covers 1986–1988 Yamaha YFM225 Moto 4 ATVs, including chassis, engine, and electrical system diagnostics for the YFM225S model
• Official 100-page Yamaha OEM publication (P/N LIT-11616-04-83, 1st Edition February 1985)
• Contains dozens of technical exploded-view diagrams, torque reference tables, and wiring system schematics
• Provides the foundation for all subsequent 1986–1988 YFM225 service and maintenance intervals

Documentation Overview

This factory service publication provides the technical data needed to maintain the 1986–1988 Yamaha YFM225 Moto 4 series. You will find sections detailing general machine identification, periodic inspection routines, and complete engine overhaul procedures. The manual breaks down engine removal, along with the disassembly of the cylinder head, transmission, and clutch assembly. Internal components get comprehensive specifications for inspection. The electrical chapters outline system troubleshooting. Chassis sections explain brake adjustments, steering inspection, and suspension settings. Appendices offer additional supporting data for technicians digging into advanced diagnostics. Keep in mind that working on ATVs involves significant physical hazards. Always observe proper shop safety protocols and use appropriate lifting equipment before applying any specifications found in these reference materials.

Technical Reference and Specifications

Inside, the manual lays out extensive technical tables covering routine maintenance, fuel-delivery specifications, and internal clearances. Detailed torque values for critical fasteners are specified throughout the chapters. For example, it lists the 43 Nm requirement for the drain plug and 15 Nm for clutch cover components. The cylinder head specification table puts the intake valve clearance at 0.05–0.09 mm. Compression pressure at sea level is documented at a standard 883 kPa. The final gear assembly requires 0.23 liters of SAE 80 API GL-4 gear oil. This documentation offers a complete contents overview of the factory structure for these early ATV models.