Positioning:
The Yamaha XT660 is a versatile dual-sport motorcycle known for its off-road capability and on-road usability. This manual caters to owners and technicians needing in-depth service information for this specific generation.
Competition:
Competes with other middleweight dual-sport motorcycles from manufacturers like Honda (e.g., Transalp), KTM (e.g., LC4 series), and Suzuki (e.g., DR-Z series) in terms of performance and intended use.
Features:
Single-cylinder, liquid-cooled engine; electronic fuel injection; robust chassis for off-road durability; capable suspension system.
Engine:
Complete overhaul, tuning, diagnostics, fuel injection system (EFI), ignition system, lubrication.
Drivetrain:
Clutch operation and replacement, transmission overhaul, final drive (chain and sprockets).
Chassis Suspension:
Front fork service and rebuild (including oil changes and seal replacement), rear shock absorber specifications and service, steering head bearing maintenance, swingarm inspection and lubrication.
Brakes:
Front and rear brake system service (hydraulic lines, calipers, master cylinders, brake pads, rotors), bleeding procedures.
Electrical:
Wiring diagrams, battery maintenance, charging system (stator, regulator/rectifier), starter motor, lighting system, instrument cluster, EFI control unit (ECU) diagnostics.
Fuel System:
EFI system diagnostics, injector servicing, fuel pump operation, fuel pressure testing.
Routine Maintenance:
Oil changes, filter replacement, spark plug replacement, chain adjustment, air filter cleaning/replacement, valve clearance checks.
Troubleshooting:
Diagnostic flowcharts for common performance issues, electrical faults, and starting problems.
Repair Rebuild:
Complete engine rebuild procedures, transmission disassembly and assembly, suspension component servicing.
Electrical Diagnostics:
Detailed troubleshooting guides for EFI system, ignition system, charging system, and all electrical components using multimeter readings and diagnostic codes.
Chassis Maintenance:
Wheel bearing service, steering head bearing adjustment, swingarm lubrication and inspection, chain lubrication and adjustment procedures.
Engine Performance Tuning:
Information on EFI adjustments, idle speed settings, and basic performance tuning principles applicable to the 660cc single-cylinder engine.
Depth:
Comprehensive, suitable for professional technicians and advanced DIY mechanics. Covers detailed diagnostic procedures, torque specifications, and internal component tolerances.
Specifications Detail:
Includes precise torque values for all fasteners, critical component clearances, bearing preloads, and material specifications.
Completeness:
Comprehensive coverage for repair, maintenance, diagnostics, and component overhaul. Intended as a complete reference for servicing the 2004 Yamaha XT660.
Engine Type:
4-stroke, Single cylinder, SOHC, 4-valve
Bore X Stroke:
100.0 mm x 84.0 mm
Cooling System:
Liquid-cooled
Horsepower Approx:
47.3 hp @ 6,000 rpm (varies by region and specific model tune)
Torque Approx:
58.1 Nm @ 5,250 rpm (varies by region and specific model tune)
Compression Ratio:
9.8:1 (typical for the 660 engine)
Fuel Delivery:
Electronic Fuel Injection (EFI) with dual throttle valves
Spark Plug Type:
NGK CR9EIX (Iridium) or equivalent
Engine Oil Capacity W Filter:
Approx. 2.2 L
Infotainment System:
Basic LCD instrument cluster displaying speed, RPM, fuel level, odometer, trip meters, and warning lights. No complex infotainment system.
Assistance Features:
Primarily focused on mechanical reliability and basic rider feedback through the instrument panel. No electronic rider aids like traction control or advanced ABS on the 2004 model.
Connectivity Features:
No integrated connectivity features.
Oil Change Interval:
Every 6,000 km or 12 months, whichever comes first (refer to manual for precise intervals).
Valve Clearance Check:
Every 12,000 km (refer to manual for precise intervals and specifications).
Spark Plug Replacement:
Every 12,000 km (refer to manual for precise intervals).
Fork Oil Type:
Yamalube Fork Oil 10W or equivalent
Fork Oil Level:
Refer to manual for precise level (typically measured from top of fork tube with spring removed)
Common Issues:
Potential for stator failures, fuel pump issues, and occasional ECU glitches. Early models might exhibit some vibration characteristics inherent to large single-cylinder engines.
Oil Filter Part Number:
Yamaha 3XF-13440-00-00 or equivalent
Air Filter Part Number:
Yamaha 5VK-14451-00-00 or equivalent
Heritage:
Yamaha has a long history in motorcycle manufacturing, particularly in off-road and dual-sport segments with iconic models like the XT500 and the more modern XT line.
Evolution:
The XT660 series, introduced in the early 2000s, marked a significant step forward for Yamaha's single-cylinder dual-sport offerings, incorporating modern technology like EFI and liquid cooling. The 2004 model represents an early iteration of this platform, with subsequent updates and variations (e.g., XT660R, XT660X, XT660Z Ténéré) appearing in later years.
Production Period:
The XT660 platform was produced for a considerable period, with the 2004 model year being part of its initial introduction phase.
