1987–1997 Yamaha Big Bear 350 4WD YFM350FW ATV Service Manual Set (P/N LIT-11616-FM-37)

Yamaha’s service documentation for the 1987–1997 Big Bear 350 4WD (YFM350FW) is compiled under P/N LIT-11616-FM-37. The set combines a base service manual and model supplements with a separate YFM350FWJ owner’s manual.

Text search, bookmarks and wiring labels: Both PDFs have OCR text and embedded bookmarks. Text recognition is incomplete on some covers and small diagram labels; dense wiring details need enlargement. The owner’s manual omits printed pages 7-8 and 7-9.

• Engine repair: Engine removal, cylinder-head and piston overhaul, crankshaft inspection, oil pump checks and recoil starter disassembly and reassembly.

• Carburetor repair: Mikuni BTM32SH teardown, float and fuel-level checks, jet and needle inspection, plus throttle and starter-cable adjustments.

• Transmission and 4WD: Clutch replacement, shift mechanism inspection, transfer and middle-drive gear service, front differential removal and rear final-drive overhaul.

• Brakes and chassis: Front hydraulic brake bleeding, rear brake service, steering knuckle inspection, toe-in adjustment and suspension bearing maintenance.

• Electrical diagnosis: CDI ignition and stator testing, starter and charging-system troubleshooting, lighting checks and model-specific circuit diagrams.

• Periodic maintenance: Valve clearance adjustment, air-filter and spark-plug service, ignition timing verification, lubrication schedules and exhaust inspection.

Yamaha wrote the service material primarily for its dealers and qualified mechanics with a grounding in mechanical repair; the owner’s manual addresses operation, routine maintenance and minor repairs.

Model Supplements and Brake Configurations

The supplements update carburetor, electrical and chassis information and are used with the base procedures. The base manual covers a mechanically operated rear disc brake; the FWH supplement and FWJ owner’s manual describe a rear drum brake. Their component and adjustment sections distinguish these configurations before brake parts are selected.

Engine, Carburetor and Clutch Repair

Engine coverage extends beyond top-end work to crankcase separation, crankshaft inspection and transmission shift forks. Clutch procedures distinguish the primary centrifugal assembly from the secondary wet multiplate clutch.

The Carburetor Sectional View shows the main, starter and float circuits. Related repair sections address the coasting-enricher diaphragm, piston valve and needle-valve seat. Carburetor specifications are revised in the model supplements.

Differential, Middle Drive and Final Drive

The Differential Gear and Constant Velocity Joints exploded view accompanies shaft, bearing, seal and boot service. The factory-assembled differential unit itself is not intended for internal disassembly. Middle Drive Gear and Driven Gear Positioning diagrams cover shim selection and gear engagement, with separate procedures for rear axle and final gear repair.

Special-tool references include the middle/final-drive gear-lash dial gauge (YM-03097) and rear axle nut wrench (YM-37132). The front drive-gear instructions warn that overtightening can deform the collapsible collar, requiring its replacement.

Starting Circuits and Electrical Tests

The Starting Circuit Operation schematic and associated flowcharts trace the neutral, reverse and brake interlocks. These checks help distinguish an interlock fault from a starter fault before parts are replaced. The YFM350FWJ wiring diagram documents the later electrical configuration, including the auxiliary DC circuit.

Component tests provide magneto source- and pickup-coil resistance readings, charging outputs, starter-motor inspection limits and oil-temperature warning-system checks.

Brake, Steering and Service Specifications

Chassis procedures cover master- and wheel-cylinder repair, brake pedal and lever adjustment, steering knuckles and tie-rod ends. Suspension coverage includes front-arm bushings, swingarm-bearing lubrication and shock-spring preload; engine removal and installation procedures also address the exhaust assembly.

Reference tables list wheel-hub, rear-axle and brake fastener torques, piston-to-cylinder clearance, camshaft dimensions and other wear limits. Machine-identification, physical-dimension, oil-requirement and differential-capacity tables accompany the maintenance schedules. Yamaha’s service precautions cover brake work, supporting the ATV and engine disassembly.

Owner’s Manual and PDF Contents

The FWJ owner’s manual covers controls, pre-operation checks, riding, routine maintenance, cleaning and storage.

The two printable PDFs contain 588 pages in total: a 442-page service compilation and a 146-page owner’s manual (4UM-28199-61). The service volume includes the YFM350FWT base manual (326 pages), YFM350FWW (12), YFM350FWA (13), YFM350FWB (17), YFM350FWF (20), YFM350FWH (28) and YFM350FWJ (25) supplements, plus one compilation cover. All covers, publication pages and the owner’s conversion table are already included in these totals.