1987-1990 Yamaha YFM350ER Moto-4 Four-Wheeler Service Manual

• Complete factory coverage for the 1987–1990 Yamaha YFM350ER Moto-4 featuring the 350 cc oil-cooled engine configuration.
• 310 pages of official OEM schematics, exploded-view diagrams, and accurate factory fastener torque specifications.
• The only workshop edition providing comprehensive assembly and disassembly teardowns for the 350 cc platform drivetrain.

Engine and Chassis Documentation

Whether you are rebuilding the top end or dialing in the carb, this technical manual provides the exact factory procedures for your Moto-4. It details everything from routine periodic adjustments to complete overhauls. You get precise data for the fuel system, including carburetor float level settings and air filter maintenance, right alongside the correct engine and final gear oil capacities. Need to check the automatic cam chain tensioner, valve clearances, or compression pressure on the 350 cc power plant? The exact factory measurements are right here.

The chassis section goes just as deep, walking you through steering system inspections, brake lever and pedal adjustments, and tire pressure management. This ensures you maintain complete OEM service coverage for the entire series. Plus, thanks to the instant download feature, you can pull these procedures up on your tablet or phone right at the workbench without waiting for shipping.

Factory Technical Specifications

Mechanics know that guesswork ruins engines. That is why this manual is packed with hard technical data to keep your build accurate and reliable. The engine service tables list cylinder head bolt torque values strictly at 40–50 N·m (29–37 lb-ft), while the cylinder head specification charts put the intake valve clearance precisely at 0.06–0.10 mm (0.002–0.004 in). Electrical troubleshooting is covered down to the exact resistance and fuse ratings for the magneto pick-up coil and related circuitry.

You will also find clear gear lash measurements to ensure your final drive assembly runs flawlessly. Before turning wrenches on these critical systems, ensure you have the proper tools and mechanical background to work safely, as improper maintenance or relying on incorrect specs can lead to serious equipment damage or injury.