Yamaha Grizzly 350 IRS YFM35FGI 2007–2010 ATV Service Manual (P/N LIT-11616-20-46)

• Coverage: Covers 2007–2010 Yamaha YFM35FGI Grizzly 350 IRS ATV applications. The factory specifications identify model codes 4S21 and 4S25, and the publication is a 373-page PDF.
• Engine work: Documents engine removal and installation, cylinder-head and valve service, cylinder/piston inspection, crankshaft and crankcase repair, oil-pump and balancer service, plus recoil-starter and AC-magneto work.
• Automatic transmission: Breaks down the V-belt drive, primary and secondary sheaves, centrifugal clutch, internal transmission, and middle gear, with sheave disassembly, shim selection, and backlash measurement.
• Shaft-drive and chassis systems: Covers front CV joints and differential, rear CV joints and final drive, the final-case wet multiple-disc rear brake, front hydraulic brakes, steering, and front/rear double-wishbone suspension.
• Electrical diagnosis: Supplies component tests, continuity checks, system-specific fault charts, cable-routing views, and the complete YFM35FGI wiring diagram.
• Factory reference data: Provides torque tables, fluid capacities and lubricant specifications, inspection limits, clearances, electrical test data, and region-specific special-tool numbers.

This is a workshop-level Yamaha service manual, not an owner's maintenance booklet. Yamaha states that it was produced primarily for its dealers and qualified mechanics and assumes a basic understanding of mechanical concepts and vehicle repair procedures. It is therefore suited to readers who already have that background, along with the measuring equipment and special tools called for by the job. The procedure format combines exploded assembly drawings, numbered job/part order charts, and illustrated step-by-step supplements.

Engine, Carburetor, and V-Belt Drivetrain

Coverage matches the 348 cm³ air-cooled SOHC single with wet-sump lubrication, oil cooler, BSR33 carburetor, electric and recoil starting, DC-CDI ignition, and shaft drive. This matters when distinguishing it from EFI or liquid-cooled models. Maintenance and diagnostic procedures cover valve-clearance adjustment, idle speed and throttle free play, ignition-timing and compression checks, engine-oil service, oil-temperature warning operation, air-filter service, and V-belt inspection.

Beyond routine service, the repair sections take the engine through removal and installation, valve train and cam timing, piston/cylinder inspection, AC magneto and starter clutch, balancer gears and oil pump, crankcase separation, crankshaft installation, and transmission inspection. Separate chapters cover carburetor inspection and reassembly, float/fuel-level adjustment, primary and secondary sheave work, the wet centrifugal clutch, and the middle-drive gear.

Final Drive, Brakes, Steering, and Suspension

The driveline chapter starts with noise diagnosis and a decision chart, then moves into front CV/differential and rear CV/final-drive repair. Factory procedures cover universal-joint disassembly, differential gear motor testing, ring-and-pinion positioning, shim selection, gear-lash measurement and adjustment, and a functional check of the 2WD/4WD/differential-lock mechanism. The rear brake is the sealed wet multiple-disc unit inside the final gear case, so the manual ties brake service to the specified friction-modified shaft-drive oil.

Chassis work covers wheel hubs and brake discs, front pad replacement, master-cylinder and caliper service, hydraulic bleeding, steering-stem bearings, tie rods and knuckles, front arms, rear arms, shock absorbers, stabilizer, and toe-in adjustment. Brake work, spring-loaded sheave service, and repairs with the ATV raised require the correct tools and secure vehicle support; follow the factory warnings before disassembly.

Electrical and Fault Diagnosis

Electrical coverage is organized as testable systems rather than a single wiring sheet. System drawings cover the ignition circuit, electric-starting circuit operation, charging circuit, signaling circuit, oil-cooler fan circuit, and 2WD/4WD selecting circuit, backed by the two-page full-machine wiring diagram. The test sections give expected resistance and voltage data for the AC magneto, pickup and rotation-sensing coils, ignition coil, rectifier/regulator, starter motor and relay, lighting, switches, relays, oil-temperature controls, and differential gear motor. A final troubleshooting chapter separates starting, idle, high-speed, driveline, shifting, clutch, overheating, brake, handling, and lighting faults by likely system.

Special Tools and Repair Cautions

The special-tool catalog gives both 90890-series and U.S./Canadian YM/YU numbers. Notable examples are the crankcase separator 90890-01135 / YU-01135-B, gear-lash measurement tool 90890-01467 / YM-01467, and sheave spring compressor 90890-04134 / YM-04134. These listings let a shop confirm tooling before committing to an internal repair.

The middle-driven-shaft bearing retainer has left-hand threads, so treating it as a conventional fastener risks thread or retainer damage. After differential or final-drive reassembly, too little gear lash is explicitly identified as destructive to the gear teeth; the manual pairs the repair with dedicated measuring tools and adjustment data.