2001 Yamaha Grizzly 660 YFM660FP ATV Service Manual (P/N LIT-11616-15-01)

This Yamaha service manual covers the 2001 Grizzly 660 YFM660FP, including the 5KM1 and 5KM5 variants. P/N LIT-11616-15-01, first edition May 2001, documents the original YFM660FP configuration.

Text search and wiring detail: The PDF has searchable text but no embedded bookmarks. Small wire-color codes and connector labels in the ignition, 2WD/4WD and overall wiring diagrams are readable when enlarged.

• Engine repair: Engine removal, cylinder-head and valve work, piston inspection, crankcase separation, crankshaft service, and valve-clearance adjustment.

• V-belt drive and transmission: Primary and secondary sheave service, centrifugal clutch inspection, shift-fork and shift-cam checks, and middle-gear adjustment.

• Shaft drive: Front and rear constant velocity joint service, differential and final-drive gear-lash adjustment, shim selection, and drive-shaft inspection.

• BSR42 carburetor: Disassembly, diaphragm and jet inspection, float-height measurement, fuel-level adjustment, and throttle and starter-cable settings.

• Cooling system: Radiator and cap checks, thermostat testing, water-pump disassembly, mechanical-seal replacement, and cooling-fan troubleshooting.

• Brakes and chassis: Hydraulic brake bleeding, master-cylinder and caliper repair, steering-stem service, wheel-bearing replacement, and suspension-arm inspection.

• Electrical diagnosis: Ignition, electric-starting, charging and 2WD/4WD tests, with circuit diagrams, connector views, and switch-continuity charts.

Yamaha wrote this manual primarily for its dealers and qualified mechanics, assuming an existing understanding of mechanical principles and machine repair.

Engine Repair and Service Specifications

The engine chapter covers rocker arms, the decompression system, camshaft timing, piston rings, balancer gears and oil-pump inspection. Recoil-starter rebuilding, AC-magneto removal and starter-clutch checks have their own procedures.

Periodic maintenance tables accompany component-specific torque tables, fluid capacities, inspection limits and clearance specifications. Oil Flow Diagrams trace the lubrication passages, while exploded views and job instruction charts identify parts and their assembly relationships.

V-Belt Drive, Differential and Final Drive

Transmission coverage extends to the reverse-drive chain, parking mechanism, clutch dogs and one-way clutch bearing. Secondary-sheave procedures identify the YM-04134 sheave spring compressor and YM-04135 sheave fixed block. Torque specifications cover the clutch carrier assembly nut.

Middle-gear and final-drive repair sections explain shim selection and backlash measurement. Front-differential coverage adds preload checks and gear-lash adjustment. The lash-measurement instructions warn that excessive force on the ring-gear holding bolt can damage the ring gear.

Internal-service limits: The factory-assembled differential gear unit and the gear motor are not intended for internal disassembly. Gear-motor testing and installation are covered, including how its position relates to differential-lock operation and the indicator display.

Carburetor and Water-Pump Service

Carburetor inspection: The Mikuni BSR42 section distinguishes the piston-valve diaphragm from the coasting-enricher diaphragm. It links float and fuel-level adjustment to needle-valve and valve-seat condition, with inspection criteria for the jets and starter plunger.

Water-pump repair: The procedures address the impeller, rubber damper, mechanical seal, oil seal and bearing. Seal installation specifies the YM-33221 mechanical seal installer, with a caution about oil or grease on the seal face. Coolant Flow Diagrams show the radiator, thermostat and connecting hoses.

Brake, Steering and Suspension Work

Separate front and rear brake procedures cover pad shims, master-cylinder kits, caliper seals and brake-hose routing. Chassis coverage includes tie-rod checks, toe-in adjustment, rear-knuckle bearings and stabilizer inspection.

Brake and steering repairs require adherence to Yamaha's safety precautions and torque specifications to prevent component failure or loss of control.

Electrical Fault Tracing

The Ignition System and 2WD/4WD Selecting System circuit diagrams accompany component tests. The overall YFM660FP Wiring Diagram supplies component and wire-color keys, and Cable Routing views show harness placement.

Electrical test specifications cover coil resistance, starter interlocks, charging output, cooling-fan control and indicator circuits. Horn diagnosis is identified specifically for Europe and Oceania.

The 2WD/4WD troubleshooting sequence checks the selection switch, relays, gear motor and wiring separately. That helps narrow down a drive-selection fault before choosing a component to replace.

PDF Contents and Page Breakdown

One printable, English-language 408-page PDF contains 387 chapter pages, 19 preliminary pages including the front cover, contents and one blank page, one publisher back page, and one final wiring-diagram page. All are included in the total.