1987-1990 Yamaha YFM350ER Moto-4 Service Manual

1987–1990 Yamaha YFM350ER Moto-4 Service Manual

• Covers the 1987–1990 Yamaha YFM350ER Moto-4 with 350 cc oil-cooled engine configuration
• Official Yamaha publication dated 1987 with revision coverage for the YFM350ER model series
• Contains 310 pages with comprehensive exploded-view diagrams and factory fastener torque specifications
• Downloads to your account within seconds of checkout
• Permanent availability in your purchase account — no re-buy required
• OCR text layer lets you jump to a torque spec by keyword
• Indexed PDF search covers every chapter and appendix
• This 1987-1990 Yamaha YFM350ER Moto-4 workshop publication is the only edition that provides the full assembly and disassembly schematics for the 350 cc platform drivetrain

Engine and Chassis Documentation

This 1987–1990 Yamaha YFM350ER Moto-4 technical manual details the full scope of engine maintenance, beginning with general information and periodic adjustment protocols. The text explains the maintenance of the fuel system, including carburetor float level settings and air filter servicing, alongside engine oil and final gear oil specifications. Readers find detailed information on the automatic cam chain tensioner, valve clearance adjustments, and compression pressure diagnostics for the 350 cc power plant. The chassis section outlines steering system inspection, brake lever and pedal adjustment, and tire pressure management to maintain what an OEM service publication covers for the Moto-4 series.

Factory Technical Specifications

Technical data is provided throughout the document to assist in component identification and assembly. Cylinder head bolt torque values are documented at 40–50 N·m (29–37 lb-ft) in the engine service data. Valve clearance for the intake is listed at 0.06–0.10 mm (0.002–0.004 in) in the cylinder head specification table. The Yamaha YFM350ER Moto-4 magneto pick-up coil and electrical system rely on specific resistance and fuse ratings documented in the electrical troubleshooting chapter. Gear lash measurements and final drive assembly are clearly presented to aid in the maintenance of the rear axle system. Reference only — always consult a certified technician before performing service on this equipment. An official 310-page Yamaha OEM workshop manual covering the 1987–1990 YFM350ER Moto-4, documenting engine, chassis, electrical, and drive system specifications for the early 350-class build.