Market Segment:
Lightweight dual-sport and supermoto motorcycles, catering to riders seeking versatility and off-road capability (XT660R) or sporty street performance (XT660X).
Competitors:
Competed against models like Honda XR650L, Suzuki DR-Z400S/SM, Kawasaki KLR650, and KTM's LC4 lineup during its production run.
Engine Configuration:
Single-cylinder, liquid-cooled, four-valve, DOHC engine renowned for its torque and tractability.
Fuel Injection:
Electronic Fuel Injection (EFI) system providing precise fuel delivery and improved throttle response.
Frame Type:
Lightweight steel diamond frame, contributing to agility and handling.
Suspension Setup:
Long-travel suspension (XT660R) for off-road use, more road-biased but still capable suspension (XT660X) for performance riding.
Engine:
Complete engine overhaul, disassembly, inspection, assembly, timing, fuel injection (FI), ignition, lubrication, cooling.
Transmission:
Gearbox removal, inspection, repair, clutch system, shift mechanism.
Chassis Suspension:
Front fork (telescopic), rear shock absorber (monoshock), swingarm, linkage system, bearings.
Brakes:
Front and rear brake systems (disc brakes), hydraulic system, caliper overhaul, master cylinder, brake lines, bleeding procedures.
Electrical System:
Wiring diagrams, battery, charging system (stator, regulator/rectifier), starter motor, lighting, instrumentation, ignition system components.
Fuel System:
Fuel tank, fuel pump, fuel injectors, throttle body, fuel pressure regulation, EFI system diagnostics.
Exhaust System:
Exhaust pipes, muffler, catalytic converter (if applicable), oxygen sensor (O2 sensor).
Frame Bodywork:
Frame inspection, subframe, body panels, seat, fuel tank removal/installation, fairings (XT660X), fenders.
Wheels Tires:
Wheel removal and installation, spoke tightening (XT660R), tire changing, balancing, wheel bearing inspection.
Maintenance:
Routine maintenance checks, oil changes, filter replacements, chain adjustment, spark plug replacement, air filter cleaning/replacement.
Troubleshooting:
Diagnostic procedures for common problems, fault code interpretation (if applicable to the EFI system), symptom-based troubleshooting guides.
Repair:
Step-by-step instructions for component removal, repair, and reassembly for all major vehicle systems.
Disassembly Assembly:
Detailed procedures for complete engine teardown and rebuild, transmission overhauls, suspension component replacement.
Torque Specifications:
Crucial torque values for all fasteners, critical engine and chassis bolts, ensuring proper assembly and preventing damage.
Diagnostic Capabilities:
Covers EFI system diagnostics, ignition system testing, sensor testing, and basic electrical system fault finding.
Rebuild Procedures:
Detailed instructions for complete engine rebuilds, including piston ring replacement, valve seat grinding, and bearing clearances.
Wiring Diagrams:
Comprehensive and often color-coded wiring diagrams for easy identification of circuits and components.
Special Tools:
Identification of required special tools for specific maintenance and repair procedures, often with diagrams.
Engine Type:
4-stroke, Liquid-cooled, DOHC, 4-valve
Displacement:
660 cc (659.7 cc)
Bore X Stroke:
100.0 mm x 84.0 mm
Compression Ratio:
10.0:1
Horsepower Peak:
Approximately 48 HP (35 kW) @ 6,000 RPM (varies slightly by market and emissions regulations)
Torque Peak:
Approximately 60 Nm (44.3 lb-ft) @ 5,250 RPM (varies slightly by market and emissions regulations)
Fuel Delivery:
Electronic Fuel Injection (EFI) with dual throttle valves
Fuel Type:
Unleaded gasoline, minimum 87 octane (RON+MON)/2)
Fuel Tank Capacity:
15 Liters (3.96 US gallons)
Overall Length:
XT660R: Approx. 2,215 mm (87.2 in) / XT660X: Approx. 2,175 mm (85.6 in)
Overall Width:
XT660R: Approx. 850 mm (33.5 in) / XT660X: Approx. 800 mm (31.5 in)
Overall Height:
XT660R: Approx. 1,230 mm (48.4 in) / XT660X: Approx. 1,175 mm (46.3 in)
Seat Height:
XT660R: Approx. 865 mm (34.1 in) / XT660X: Approx. 855 mm (33.7 in)
Wheelbase:
XT660R: Approx. 1,485 mm (58.5 in) / XT660X: Approx. 1,480 mm (58.3 in)
Dry Weight:
XT660R: Approx. 170 kg (375 lbs) / XT660X: Approx. 175 kg (386 lbs)
Wet Weight:
XT660R: Approx. 185 kg (408 lbs) / XT660X: Approx. 190 kg (419 lbs) (Estimates, including all fluids and a full tank)
Maximum Load:
Refer to manual for specific payload capacity, typically around 180-200 kg (rider + luggage).
Oil Change Interval:
Typically every 5,000 km (3,000 miles) or 6 months, whichever comes first. Refer to manual for exact mileage/timeframe.
Oil Filter Replacement:
Recommended to replace at every oil change.
Air Filter Cleaning:
Inspection/cleaning every 5,000 km (3,000 miles), replacement as needed.
Spark Plug Replacement:
Typically every 10,000 km (6,000 miles) or as per manual recommendation.
Valve Clearance Check:
Initial check around 1,000 km (600 miles), then every 10,000 km (6,000 miles). This is a critical item for single-cylinder engines.
Engine Oil Type:
Yamalube 4 (or equivalent) 10W-40 API SG or higher, JASO MA certified.
Engine Oil Capacity:
2.4 Liters (2.53 US qt) without filter change, 2.6 Liters (2.75 US qt) with filter change.
Coolant Type:
Permanent type antifreeze coolant (ethylene glycol-based) mixed with distilled water in a 50:50 ratio.
Brake Fluid Type:
DOT 4 hydraulic brake fluid.
Gearbox Oil Type:
Yamalube Gear Oil (or equivalent) SAE 80 API GL-4.
Gearbox Oil Capacity:
0.60 Liters (0.63 US qt)
Fuel Pump Reliability:
Some early models could experience fuel pump issues, particularly if running on low-quality fuel or with clogged filters.
Stator Failures:
As with many motorcycles of this era, stator failure affecting the charging system can occur over time. Regular voltage output checks are recommended.
Clutch Lever Pivot Point:
The clutch lever pivot point can sometimes wear, leading to a sloppy feel. Lubrication and potential replacement are covered in the manual.
Suspension Seals:
Fork seal leaks are a common maintenance item on any motorcycle with telescopic forks, especially with extended off-road use.
Yamaha Motorcycles:
Yamaha Motor Company has a long and illustrious history in motorcycle manufacturing, known for innovation, performance, and reliability across various segments.
Xt Series:
The XT660 series builds upon Yamaha's heritage of dual-sport and single-cylinder off-road motorcycles, dating back to the iconic XT500 and XT600.
Xt660R Xt660X Development:
Introduced as a modern interpretation of the dual-sport concept, leveraging a fuel-injected single-cylinder engine for improved emissions and performance. The XT660X variant was a factory supermoto conversion, featuring stiffer suspension, smaller front wheel, and street tires.
Manufacturing Location:
Primarily manufactured in Japan by Yamaha Motor Co., Ltd.
Production Period:
2004-2008 for the XT660R and XT660X models covered by this manual. The XT660 platform continued in different forms in some markets beyond 2008.
