1990–1995 Yamaha Moto 4 350 / YFM350ER (A-G) ATV Service & Repair Manual (P/N LIT-11616-07-51)

Yamaha's service manual P/N LIT-11616-07-51 covers maintenance and repair for the 1990–1995 Moto 4 350 / YFM350ER (A-G). The internal specifications and circuit diagrams identify the YFM350ERA, model code 3HP2.

Delivered as one 331-page PDF in English.

• Engine repair: Engine removal, crankcase separation, valve and cylinder-head service, crankshaft inspection, cam-chain timing, and oil-pump inspection.

• Clutch and transmission: Primary centrifugal and secondary multi-plate clutch service, dual-range transmission inspection, and High/Low/Reverse selector-cable adjustment.

• Carburetion: Mikuni BTM32SH teardown and assembly, float-height and fuel-level adjustment, coasting-enricher inspection, and wire-cylinder cable service.

• Shaft drive: Middle-gear overhaul, universal-joint service, pinion and ring-gear shim selection, and final-gear lash measurement and adjustment.

• Brakes and chassis: Front drum and rear disc brake repair, rear-axle and steering-knuckle inspection, toe-in alignment, and swingarm bearing replacement.

• Electrical diagnosis: CDI ignition, electric starting, charging, lighting, and indicator-circuit troubleshooting, with wiring diagrams and component test specifications.

Written primarily for Yamaha dealers and qualified mechanics, this manual assumes an understanding of mechanical repair procedures and access to the specified workshop tools.

Engine Overhaul and Service Specifications

Engine technical data covers tolerances for cylinder head warpage, piston-to-cylinder clearance, and camshaft dimensions, plus valve and guide wear and clutch-plate condition. The cylinder and piston inspection criteria help assess whether reboring or replacement is called for.

Engine exploded views accompany assembly procedures covering balancer-gear alignment, CDI rotor installation, primary-clutch one-way-bearing orientation, and the secondary clutch's different friction and steel plates.

Compression-pressure testing includes a diagnostic comparison for low readings, alongside valve-clearance and ignition-timing checks. Component-specific torque tables distinguish fastener sizes; lubrication schedules and engine/final-drive fluid-capacity data support servicing and reassembly.

Mikuni Carburetor and Cable Controls

The carburetor sectional view identifies the main metering, starter, and float systems. Repair coverage includes the piston valve, jet needle, starter plunger, needle-valve seat, and coasting-enricher diaphragm, with separate checks for float height and running fuel level.

The wire-cylinder section covers the sliders and linked piston-valve and throttle-valve cables, including inspection and reassembly.

Middle Gear and Final Drive Repair

The middle-gear section includes damper-spring disassembly and shim calculations based on markings on the gears, housing, and crankcase. Final-drive coverage adds thrust-washer selection, ring-gear stopper clearance, and a symptom-based troubleshooting chart for shaft-drive noise and jerky operation.

Yamaha warns that overtightening the middle-gear bearing housing during lash setup can leave insufficient clearance and damage the gears.

Tool references include the universal-joint holder YM-04062 and final-drive bearing-retainer wrench YM-04050.

Brake, Steering, and Suspension Service

Rear-brake instructions address the cable-operated caliper, brake-pad and disc wear, and both lever and pedal adjustment. Steering repair includes tie-rod-end positioning; suspension coverage includes front-arm bushings, swingarm pivots, and rear-shock spring-preload adjustment.

The rear-axle section warns that direct hammer blows can damage axle threads and splines. Follow the manual's support precautions during rear-wheel-drive and swingarm removal.

Starting, Charging, and Indicator Troubleshooting

The starting-circuit diagram and no-crank test chart connect the neutral/reverse switches, front stop switch, and cut-off relay to their diagnostic checks. This helps distinguish an interlock fault from a starter-motor problem.

Testing covers pickup and source coils, the A.C. magneto generator's charging coils, and the rectifier/regulator. Starter-motor brush, commutator, and armature inspections are included, along with “OIL TEMP” checker and indicator-circuit tests. Cable-routing diagrams locate the harness and associated control cables.

File Format and Readability

The page total includes 12 preliminary pages (cover, notices, symbols, index, and contents), one blank page, and the final one-page YFM350ERA wiring diagram.

Text search: Not available in this PDF.

Navigation: 63 embedded PDF bookmarks provide access to chapters, subsections, and the final wiring diagram.

Diagram readability: Small wire-color codes and connector labels on the final wiring diagram are readable when enlarged.