Category Description:
The Yamaha Tri-Z 250 was a highly regarded, high-performance sport ATV during its production run, known for its agility and powerful two-stroke engine, competing with models like the Honda TRX250R and Kawasaki Tecate-4.
Key Competitors:
Honda TRX250R, Kawasaki Tecate-4 (KXT250), Suzuki LT250R.
Unique Selling Points:
Liquid-cooled two-stroke engine, powerful acceleration, advanced suspension for its era, lightweight design, and a dedicated fanbase for its off-road capabilities.
Engine:
Complete engine overhaul, top-end rebuild, bottom-end inspection, carburetor tuning, cooling system maintenance, lubrication system diagnostics.
Transmission:
Clutch operation and adjustment, gear shifting mechanisms, transmission fluid checks and changes, internal transmission component inspection.
Chassis:
Frame inspection, suspension tuning (front and rear), steering system overhaul, brake system maintenance (hydraulic lines, calipers, pads), wheel bearing service, swingarm and linkage lubrication.
Electrical:
Ignition system diagnostics, lighting circuits, charging system (stator, rectifier/regulator), battery maintenance, wiring diagrams, troubleshooting of common electrical faults.
Maintenance:
Scheduled maintenance intervals, oil changes, filter replacements (air, fuel), spark plug replacement, coolant flushes, chain adjustment and lubrication.
Repair:
Engine component replacement, suspension damper rebuild, carburetor cleaning and rebuilding, brake caliper servicing, electrical component diagnosis and repair.
Troubleshooting:
Step-by-step diagnostic procedures for common performance issues, starting problems, electrical failures, and mechanical malfunctions.
Depth:
Comprehensive, covering basic maintenance to full engine and chassis rebuilds, including detailed torque specifications and diagnostic flowcharts.
Printability:
Printable sections as needed, allowing users to print only relevant pages.
Image Resolution:
High-resolution scans for clear diagrams, illustrations, and text.
Binding:
Digital (PDF Download) - Not applicable for physical binding.
Paper Type:
Digital (PDF Download) - Not applicable for physical paper type.
Engine Type:
Liquid-cooled, 2-stroke, reed valve induction
Displacement:
239cc (for most common models)
Bore X Stroke:
68.0 mm x 64.0 mm
Compression Ratio:
Approx. 7.1:1 (varies slightly by year/model)
Horsepower:
Estimated 30-35 HP (at crankshaft, depending on tuning and year)
Torque:
Estimated 20-23 lb-ft (at crankshaft, depending on tuning and year)
Carburetor:
Mikuni VM34SS (single carburetor)
Fuel Type:
Unleaded gasoline (minimum 91 octane recommended), mixed with 2-stroke oil
Fuel Oil Ratio:
50:1 (Yamalube 2R recommended, consult manual for alternatives)
Cooling Method:
Liquid-cooled
Coolant Type:
Ethylene glycol-based antifreeze, 50/50 mix with distilled water
Lubrication Type:
Premix (fuel/oil) and separate oil injection system for crankcase lubrication (on some models/configurations)
Transmission Type:
Constant-mesh 6-speed manual
Clutch Type:
Wet, multi-disc
Drive System:
Chain drive to rear wheel
Gear Ratios:
Specific ratios detailed in the manual for each gear.
Transmission Fluid:
Yamaha Gear Oil (or equivalent specified API GL-4, SAE 80W transmission oil)
Overall Length:
Approx. 1830 mm (72.0 in)
Overall Width:
Approx. 765 mm (30.1 in)
Overall Height:
Approx. 1060 mm (41.7 in)
Dry Weight:
Approx. 163 kg (359 lbs)
Fuel Capacity:
Approx. 11.0 L (2.9 US gal)
Front Tire Size:
21x7-10 (common)
Rear Tire Size:
20x10-9 (common)
Wheel Bolt Pattern:
4/110 (common, may vary slightly)
Oil Change Interval:
Every 1000 km (600 miles) or annually, whichever comes first. Engine oil change interval for transmission oil is also crucial (consult manual for specifics).
Air Filter Cleaning:
Every 10-20 operating hours or as needed based on conditions. Replacement every 1-2 years.
Spark Plug Replacement:
Every 3000 km (1800 miles) or annually. Inspect at 1000 km (600 miles).
Engine Oil Type:
Yamalube 2-stroke oil (or specified equivalent meeting JASO FD or FC standards) for premix.
Transmission Fluid Type:
API GL-4, SAE 80W Gear Oil.
Coolant Capacity:
Approximately 1.5 L (1.6 US qt)
Common Problems:
Carburetor gumming due to fuel age, clutch wear, suspension seal leaks, occasional electrical connector corrosion, reed valve failure if not maintained properly.
Performance Tips:
Proper jetting for altitude, regular carburetor cleaning, and correct fuel/oil mix are crucial for optimal performance and engine longevity.
Yamaha Atv Legacy:
Yamaha has a long history of producing high-performance ATVs, with the Tri-Z 250 being a significant model in the development of sport ATVs. Yamaha's motorsport heritage extends across motorcycles and other recreational vehicles.
Tri Z Development:
The Tri-Z 250 was Yamaha's answer to the burgeoning sport ATV market, building upon earlier ATV designs and incorporating advanced features for improved performance and handling.
Manufacturing Locations:
Primarily manufactured in Japan.
