Yamaha Grizzly 450 (YFM45FGX) 4x4 2007–2008 Owner's Manual (P/N LIT-11626-21–46, LIT-11616-16-01)

• 2008 Yamaha Grizzly 450 YFM45FGX 4x4: coverage is tied to the factory YFM45FGX and 17S-series identification, including panel-wheel and cast-wheel configurations.
• 756 PDF pages total / 732 non-duplicated pages: a 182-page owner's manual, P/N LIT-11626-21-46, plus the assembled service file containing P/Ns LIT-11616-16-01, LIT-11616-17-25, LIT-11616-18-35, and LIT-11616-21-46. One 24-page YFM450FAS supplement is repeated in the service PDF.
• Covers engine removal, cylinder-head and valve-train repair, cylinder and piston inspection, crankcase separation, crankshaft and oil-pump work, transmission inspection, and final assembly checks.
• Details primary and secondary sheave service, centrifugal clutch repair, Mikuni carburetor disassembly and fuel-level adjustment, plus radiator, thermostat, and water-pump procedures.
• Provides front differential, CV-joint, rear final-drive, drive-shaft, and universal-joint work, including differential gear-motor testing, pinion and ring-gear positioning, gear-lash measurement, and shim adjustment.
• Addresses the YFM45FGX wet multi-plate rear brake, front hydraulic brakes, steering, wheel hubs, suspension, rear knuckles and stabilizer, along with ignition, starting, charging, lighting, cooling, and On-Command 2WD/4WD fault tracing.
• Owner coverage includes warning-label locations, pre-ride checks, cold and warm starting, drive-select and reverse operation, cargo and trailer limits, terrain-riding procedures, periodic maintenance, troubleshooting charts, and minor repair.

Operational and Maintenance Coverage

The owner's manual is Yamaha's first edition dated June 2007. It explains the multifunction display, indicator and warning lights, fuel gauge, handlebar switches, On-Command four-wheel drive and differential lock, speed limiter, drive select lever, recoil starter, shock adjustment, carriers, trailer hitch, and auxiliary DC jack. The operating chapters separate cold-start and warm-start procedures, then cover reverse, break-in, parking, load handling, hill travel, side slopes, shallow water, rough terrain, and recovery from stalls or slides.

Pre-operation and owner-maintenance sections cover fluid levels, brakes, tires, controls, fasteners, spark plug and oil-filter service, air-filter and spark-arrester cleaning, V-belt cooling-duct checks, carburetor idle and throttle adjustment, valve-clearance inspection, drive-select safety-cable adjustment, axle boots, bearings, battery, fuses, lamps, and wheel removal. The loading section sets the total ATV load limit at 210.0 kg (463 lb) and separately lists carrier, storage-compartment, trailer-pulling, and tongue-weight limits. This is the operating and minor-maintenance document; internal diagnosis and repair belong to the service material.

Factory Repair and Diagnostic Coverage

The service material is cumulative. Yamaha directs the YFM45FGX supplement to be used with the YFM450FAR base service manual and the YFM450FAS and YFM450FAT supplements, all included here. The final supplement is not a stand-alone repair manual. The base volume supplies the engine, carburetion, cooling, drivetrain, chassis, electrical, and troubleshooting chapters; the later supplements carry forward changes needed for the YFM45FGX build.

Engine repair runs from removal and installation through the cylinder head, camshaft, rocker arms, valves, cylinder, piston, recoil starter, A.C. magneto, primary and secondary sheaves, clutch, crankcase, crankshaft, oil pump, transmission, and middle gear. Shop procedures use exploded diagrams, numbered job charts, inspection limits, installation notes, and component-specific torque data. Cooling-system work covers the radiator, thermostat, and water pump, while the BSR33 Mikuni carburetor section handles disassembly, inspection, reassembly, and float-chamber fuel-level setting.

Drivetrain coverage goes well beyond fluid changes. It covers front and rear constant-velocity joints, the differential and gear motor, drive shafts and universal joints, final-drive pinion and ring gears, bearing replacement, thrust-clearance checks, gear-lash measurement, shimming, and operational checks. Electrical diagnosis uses system circuit diagrams and test charts for ignition, electric starting, charging, lighting, signals, cooling-fan control, switches, and 2WD/4WD selection. General troubleshooting addresses hard starting, poor idle or high-speed performance, shifting and clutch faults, overheating, braking, unstable handling, and shaft-drive noise.

Model-Specific Reference Depth

The covered machine uses the 421cc liquid-cooled SOHC single-cylinder engine with a Mikuni BSR33 carburetor. The YFM45FGX supplement distinguishes 17S1/17S5, 17S2/17S6, 17S3/17S7, 17S4, and 17SA/17SB/17SC market and wheel configurations. Reference sections provide fluid specifications and capacities, tightening-torque tables, wear limits, clearances, carburetor settings, electrical test values, lubrication points, and cable-routing data.

Named visual references include the Coolant Flow Diagrams, Oil Flow Diagrams, Cable Routing views, Ignition System Circuit Diagram, 2WD/4WD Selecting System Circuit Diagram, and YFM45FGX 2008 Wiring Diagram. Yamaha tool listings identify the crankcase separating tool YU-01135-A/90890-01135, fuel-level gauge YM-01312-A/90890-01312, sheave spring compressor YM-04134/90890-04134, gear-lash tool YM-01467/90890-01467, and universal-joint holder YM-04062/90890-04062.

Two cautions show why the factory procedures matter. The drivetrain chapter warns that insufficient gear lash after reassembly can destroy the gear teeth, and the crankcase section requires transmission operation to be checked before the case bolts are torqued. The service manual assumes mechanic-level repair knowledge and carries section-specific warnings for fuel, hot pressurized coolant, brake fluid, battery service, rotating parts, and raised-vehicle work.