Market Segment:
High-performance motocross competition bike
Key Competitors:
Honda CR500, Yamaha YZ490, Suzuki RM465/RM490
Engine Type:
Liquid-cooled, two-stroke, single-cylinder
Power Delivery:
Known for its broad, tractable powerband and significant torque
Handling:
Stable and predictable handling characteristics
Engine Service:
Complete overhaul, internal components, cooling system, lubrication system
Fuel System:
Carburetor service, fuel tank, fuel lines, petcock
Ignition System:
CDI unit, ignition coil, spark plug, timing
Transmission Service:
Clutch, gearbox, shift mechanism, lubrication
Suspension Front:
Fork assembly, seals, springs, damping adjustments
Suspension Rear:
Monoshock, linkage, shock absorber, spring preload
Brakes Front:
Disc brake caliper, master cylinder, brake lines, pads, fluid
Brakes Rear:
Disc brake caliper, master cylinder, brake lines, pads, fluid
Cooling System:
Radiator, hoses, coolant, water pump
Electrical System:
Lighting, charging system, wiring diagrams, battery
Exhaust System:
Muffler, expansion chamber, mounting
Frame And Bodywork:
Frame, subframe, seat, fenders, plastics
Wheels And Tires:
Spokes, rims, hubs, tire installation, balancing
Maintenance:
Scheduled maintenance, oil changes, filter replacements, chain adjustment
Troubleshooting:
Diagnosis of common problems, electrical issues, engine performance issues
Disassembly And Assembly:
Step-by-step instructions for component removal and installation
Adjustments:
Carburetor tuning, suspension settings, clutch engagement, brake levers
Repair:
Detailed repair procedures for all major components and systems
Special Tool Usage:
Identification and illustration of required special service tools
Wiring Diagrams:
Comprehensive electrical schematics for troubleshooting and repair
Depth:
Comprehensive (Bumper-to-Bumper Coverage)
Target Audience:
Mechanics and DIY enthusiasts
Illustrations:
Detailed pictorial diagrams, exploded views, photographs, and drawings
Specifications:
Service data, factory specifications, allowable limits, torque values
Engine Type:
Liquid-cooled, two-stroke, single-cylinder
Displacement:
494cc (approximately)
Bore X Stroke:
86.0 mm x 86.0 mm (typical for later models)
Compression Ratio:
Varies by year, typically around 6.8:1 to 7.4:1
Horsepower:
Estimated 50-60+ HP (depending on year and tune)
Torque:
Strong low-to-mid range torque
Carburetor Size:
Typically 36mm or 38mm Keihin PWK
Fuel Type:
Unleaded gasoline with appropriate two-stroke oil pre-mix
Premix Ratio:
Refer to manual for specific recommendations (typically 40:1 or 50:1)
Oil Change Interval:
Refer to manual; typically after every few races or a set number of riding hours for motocross use.
Air Filter Cleaning:
Frequent cleaning and oiling recommended, especially in dusty conditions.
Spark Plug Replacement:
Refer to manual; periodic replacement based on usage.
Piston Ring Replacement:
Recommended during top-end rebuilds, interval dependent on riding conditions.
Engine Oil:
Refer to manual for specific grade and viscosity (e.g., SAE 10W-40, API SG or higher).
Coolant:
Permanent type anti-freeze coolant (e.g., ethylene glycol based) mixed with distilled water.
Brake Fluid:
DOT 3 or DOT 4 hydraulic brake fluid.
Power Valve Sticking:
Carbon buildup can cause the power valve to stick, affecting engine performance. Requires regular cleaning.
Clutch Wear:
Heavy use can lead to clutch plate wear and potential slippage. Proper adjustment and timely replacement are key.
Suspension Seals:
Fork and shock seals can wear over time, leading to leaks. Regular inspection and replacement are necessary.
Kickstarter Engagement:
Some models may experience issues with the kickstarter engagement mechanism if not properly maintained.