2002–2008 Yamaha YFM660FP Grizzly ATV OEM Service Manual (P/N LIT-11616-15-01)

This Yamaha service publication (LIT-11616-15-01, manual code 5KM-28197-E0) details periodic maintenance schedules, engine overhauls, and electrical troubleshooting for the 2002–2008 YFM660FP Grizzly ATV. The specifications identify model codes 5KM1 and 5KM5.

Text search and wiring detail: The technical chapters contain searchable PDF text, but the file has no embedded bookmarks. Small wiring labels and connector details require zooming.

• Engine repair: Liquid-cooled SOHC four-stroke engine removal, cylinder-head and valve inspection, piston checks, crankcase separation, and crankshaft installation.

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

• Fuel and cooling: Mikuni BSR42 carburetor overhaul, fuel-level adjustment, radiator-cap testing, thermostat inspection, and water-pump seal replacement.

• Shaft drive: Front and rear constant velocity joints, differential gear-lash measurement, final-drive pinion and ring-gear positioning, and shim selection.

• Brakes and chassis: Brake-disc inspection, master-cylinder and caliper overhaul, hydraulic brake bleeding, steering-knuckle service, toe-in adjustment, and suspension checks.

• Electrical troubleshooting: Ignition, starting, and charging tests, switch-continuity checks, and circuit diagrams for the 2WD/4WD selecting system.

Written primarily for Yamaha dealers and qualified mechanics, the manual assumes a basic understanding of mechanical service and machine repair.

Engine, Sheaves, and Transmission Repair

The engine section covers camshaft and decompression-system inspection, valve-guide replacement, valve-seat work, and timing-chain installation. Service checks include valve-clearance and idle-speed adjustment, spark-plug inspection, and compression testing.

Bottom-end procedures include oil-pump and relief-valve checks. The recoil starter and AC magneto have separate removal, inspection, and installation procedures.

Sheaves and shifting: Primary-sheave weights and secondary-sheave torque cams have their own inspection criteria. The procedures identify spring compressor YM-04134; transmission repair extends to the shift cam, shift forks, reverse-drive chain, and parking mechanism.

Differential and Final-Drive Service

Drivetrain documentation explains the operation of the front differential in 2WD, 4WD, and Diff-Lock modes alongside rear final drive assemblies. Its explanation of Diff-Lock standby and engagement helps distinguish a normal flashing engagement indicator from a system fault.

Differential and final-drive procedures cover gear-lash measurement, shim selection, and pinion/ring-gear positioning. The factory-assembled internal differential unit and the gear motor are not intended for disassembly.

Middle-gear repair notes identify the left-hand-thread bearing retainer and warn about shaft-thread damage during press work.

Carburetor and Cooling-System Work

The Mikuni BSR42 carburetor section covers the vacuum piston, coasting-enricher diaphragm, needle-valve/seat inspection, and float-height adjustment. Fuel-level measurement uses gauge YM-01312-A.

Cooling coverage includes radiator-cap pressure testing, thermostat operation checks, and water-pump seal installation using mechanical seal installer YM-33221. Impeller-shaft alignment is checked after assembly.

Brake, Steering, and Suspension Service

Chassis tear-downs cover front and rear brake disc procedures, master cylinders and calipers, steering knuckles, wheel bearings, and suspension arms. Toe-in and shock-spring preload adjustments are included.

The brake repair section warns that cleaning solvents can swell and distort caliper seals. Working on high-torque ATV drivetrains and suspension systems carries inherent physical risks; the manual specifies secure support for a raised ATV.

Electrical Circuits and Fault Isolation

Ignition, electric-starting, charging, lighting, cooling-fan, and 2WD/4WD selecting-system circuit diagrams accompany troubleshooting charts and connector tests. Ignition-coil tests cover both primary and secondary windings. The 4WD checks distinguish relay, handlebar-switch, gear-motor, and wiring faults.

Separate signal-system tests cover the gear-position and differential-lock indicators; horn checks are marked for Europe and Oceania. The full-machine wiring diagram includes wire-color codes and connector views.

Factory Specifications and Assembly References

Component-specific torque tables, fluid-capacity charts, wear limits, clearances, and electrical resistance specifications accompany the procedures. Exploded diagrams are paired with job instruction charts. Coolant flow diagrams, oil flow diagrams, and cable routing views provide additional installation references.

English PDF and Included Pages

Supplied as one printable English PDF. The 407-page PDF includes 387 pages across ten technical chapters, 18 opening pages (cover, reader instructions, contents, and one blank page), one back cover, and one full-machine wiring-diagram page. All are included in the total.