2004 Yamaha Raptor 660 YFM660RT Owner's Manual (P/N LIT-11616-14-21, LIT-11626-18–12)

• 545 pages across two PDFs — a 359-page service volume containing the 329-page YFM660RN/YFM660RNC Service Manual and 30-page YFM660RP Supplementary Service Manual, plus a separate 186-page YFM660RT Owner’s Manual. Yamaha publication numbers are LIT-11616-14-21 (July 2000), LIT-11616-15-31 (August 2001), and LIT-11626-18-12 (March 2004), all first editions.
• Model-code coverage is explicit: the full repair manual is written for YFM660RN/YFM660RNC, the supplement adds changed YFM660RP service data, and the operating manual is identified as YFM660RT.
• Engine repair sections cover removal, cylinder head and camshaft service, decompression and timing components, valves, piston and cylinder, AC magneto, clutch, oil pump, shift mechanism, crankcase, crankshaft and balancer, and transmission inspection and reassembly.
• Chassis work includes front and rear wheels, rear axle and hubs, hydraulic brake master cylinders and calipers, steering stem and tie-rods, front arms and shocks, rear shock and relay arm, swingarm, and O-ring drive-chain service.
• Cooling, carburetion, and electrical chapters document radiator, thermostat, and water-pump repair; twin-carburetor disassembly, synchronization checks, and fuel-level adjustment; and circuit-based diagnosis of ignition, starting, charging, lighting, signal, and cooling-fan systems.
• The YFM660RT owner’s volume explains controls, reverse operation, cold and warm starting, shifting, engine break-in, pre-ride checks, suspension adjustment, hill and side-slope riding, shallow-water operation, routine maintenance, and troubleshooting charts.
• Exploded job diagrams, job-order charts, coolant-flow and cable-routing views, model-specific wiring diagrams, torque tables, fluid and lubricant data, inspection limits, adjustment specifications, and electrical test values support the covered repair work.

Service Manual Repair Coverage

The service PDF is a Yamaha dealer-level workshop publication, not merely an operating guide. Its base volume identifies model codes 5LP1 for non-California YFM660RN and 5LP3 for California YFM660RNC. The YFM660RP supplement identifies 5LP5 for the U.S. model and is intended to be used with the RN/RNC manual rather than as a stand-alone book. It adds revised specifications and cable routing, updated maintenance information, rear-shock and relay-arm procedures, swingarm and drive-chain changes, AC-magneto coverage, and a separate RP wiring diagram. Buyers looking specifically for an RT-labeled repair manual should note that YFM660RT appears on the owner’s manual, while the workshop coverage is labeled RN/RNC and RP.

The repair depth runs well beyond scheduled maintenance. Periodic-check sections cover valve-clearance adjustment, compression testing, carburetor idle and synchronization checks, clutch and brake adjustment, steering inspection and toe-in, suspension setup, drive-chain alignment, charging-system checks, and lighting adjustment. Major component chapters use exploded assemblies and ordered job charts for removal, inspection, disassembly, reassembly, and installation. Separate troubleshooting sections trace hard starting, poor idle or high-speed performance, shift faults, clutch slip or drag, overheating, weak brakes, unstable handling, shock problems, and lighting failures.

Operation and Maintenance Overview

The YFM660RT owner’s manual retains the practical material needed before and during operation. Control-function coverage explains the main switch, warning and indicator lights, handlebar switches, throttle and speed limiter, clutch and brake controls, parking brake, shift pedal, reverse knob, fuel cock, starter choke, seat, and front and rear suspension adjusters. Pre-operation checks address brakes, fuel, engine oil, coolant, chain condition, throttle action, fasteners, lights, switches, tire condition, and tire-pressure inspection.

Operating guidance covers cold and warm starts, reverse use, shifting, acceleration and deceleration, parking, loading, and the factory break-in period. The riding chapter is specific to a high-performance sport ATV, with illustrated guidance for turning, climbing and descending hills, crossing side slopes, shallow water, rough terrain, and controlled recovery from sliding or stalling. Owner-level maintenance includes engine oil and filter service, coolant replacement, spark plug and air-filter care, spark-arrester cleaning, carburetor and idle adjustment, brake and clutch checks, drive-chain care, battery and fuse service, bulb replacement, troubleshooting charts, cleaning, storage, and a maintenance record.

Specifications, Diagrams, and Shop References

The specification chapters provide the data categories a technician needs while carrying out the procedures: model identification, engine and chassis specifications, component-specific torque tables, lubrication points, approved fluids, capacities, carburetor setup data, wear limits, clearances, suspension and steering adjustment data, and electrical resistance and output checks. These tables are more useful in context than isolated numbers because the service volume separates base RN/RNC information from the changed RP data.

Useful visual references include the complete YFM660RN/YFM660RNC wiring diagram, the revised YFM660RP wiring diagram, coolant-flow diagrams, cable-routing views, and circuit diagrams for the ignition, electric-starting, charging, lighting, signal, and cooling-fan systems. The repair chapters also open with exploded views for assemblies such as the brake calipers, steering stem, clutch, crankcase, water pump, and carburetors.

Special-tool listings give both U.S./Canada numbers and the corresponding 90890-series numbers. Examples include the crankcase separating tool YU-01135-A / 90890-01135, flywheel puller YU-33270 / 90890-01362, clutch holding tool YM-91042 / 90890-04086, and water-pump mechanical-seal installer YM-33221 / 90890-04078.

Several manual-specific repair cautions are worth noting. Direct hammering on the rear axle can damage its threads and splines, while striking crankcase mating surfaces during separation can ruin the sealing faces. The brake chapters warn that wrong or mixed fluid can deteriorate rubber seals and cause leakage, and the drive-chain section warns that pressure washing, steam, gasoline, harsh solvents, or a coarse brush can damage the chain’s O-rings. Brake hydraulics, the gas-charged rear shock, battery work, and internal engine repair should be handled with the safety precautions and skill level specified by Yamaha.