Positioning:
The TT-R90 was positioned as an entry-level, youth-oriented off-road motorcycle, designed for recreational riding and introducing younger riders to the sport of motorcycling.
Competitors:
Competed with similar-sized models from brands like Honda (e.g., CRF70F), Kawasaki (e.g., KLX110, though slightly larger displacement later), and Suzuki (e.g., JR50, LT-Z50).
Features:
Easy-to-use power delivery, automatic clutch, low seat height, durable construction, and the iconic Yamaha reliability.
Value:
This manual is an essential tool for owners and mechanics to maintain, diagnose, and repair the 2001 Yamaha TT-R90, ensuring its longevity and optimal performance, mirroring the resources used by authorized Yamaha service centers.
Engine:
Complete engine disassembly, assembly, inspection, and repair; including cylinder, piston, crankshaft, camshaft, valves, cooling system (if applicable), lubrication system.
Transmission:
Gearbox inspection, disassembly, assembly, lubrication, and troubleshooting.
Fuel System:
Carburetor adjustment, cleaning, overhaul, fuel tank, fuel lines, and fuel pump (if applicable).
Ignition System:
CDI unit, spark plug, ignition coil, wiring, timing checks.
Electrical System:
Wiring diagrams, lighting system, battery, charging system (stator, regulator/rectifier), starting system.
Chassis:
Frame inspection and repair, sub-frame.
Suspension:
Front fork disassembly, assembly, oil levels, seals, rear shock absorber inspection and adjustment.
Brakes:
Front and rear brake system inspection, service, including brake levers, calipers, master cylinders, brake pads, brake fluid replacement, and bleeding procedures.
Wheels And Tires:
Wheel bearing inspection, tire replacement, spoke tensioning, wheel balancing.
Exhaust System:
Exhaust pipe and muffler inspection, removal, and installation.
Control Systems:
Throttle control, clutch control, shifter operation, cable adjustment.
Routine Maintenance:
Oil changes, filter replacements, chain adjustments, lubrication points, spark plug checks, air filter cleaning/replacement.
Troubleshooting:
Systematic diagnosis of common problems with step-by-step solutions.
Repair Procedures:
Detailed instructions for component removal, installation, and overhaul.
Overhaul Instructions:
Comprehensive rebuild procedures for major components like the engine and transmission.
Diagnostics:
Explains how to identify and fix mechanical and electrical faults.
Specifications And Tolerances:
Provides critical measurements, clearances, and torque values for proper assembly and function.
Depth:
Comprehensive, covering everything from basic rider maintenance to full engine rebuilds and component overhauls.
Target Audience:
Professional technicians, experienced DIY mechanics, and serious enthusiasts.
Engine Type:
Four-stroke, SOHC, air-cooled
Displacement:
88cc (Actual displacement may vary slightly based on bore/stroke specifics for the 2001 model)
Bore X Stroke:
47.0 mm x 51.1 mm (Typical for this engine family)
Compression Ratio:
9.5:1 (Typical)
Horsepower:
Approx. 6-7 HP (Estimated for this class of engine)
Torque:
Not typically advertised, but designed for tractable low-end torque for off-road use.
Carburetor Type:
Mikuni VM Series (e.g., VM16SH or similar) or Keihin
Fuel Type:
Unleaded gasoline
Fuel Tank Capacity:
Approximately 3.0 Liters (0.8 Gallons)
Overall Length:
Approx. 1580 mm (62.2 inches)
Overall Width:
Approx. 700 mm (27.6 inches)
Overall Height:
Approx. 930 mm (36.6 inches)
Wheelbase:
Approx. 1105 mm (43.5 inches)
Seat Height:
Approx. 665 mm (26.2 inches)
Dry Weight:
Approx. 72 kg (159 lbs)
Curb Weight:
Not typically specified for this model, but likely around 75-77 kg.
Front Suspension Travel:
Approx. 110 mm (4.3 inches)
Rear Suspension Travel:
Approx. 110 mm (4.3 inches)
Engine Oil Change:
Every 1000 km (600 miles) or 6 months, whichever comes first. (Refer to manual for exact factory spec)
Spark Plug Check:
Every 1000 km (600 miles).
Air Filter Cleaning:
Every 500 km (300 miles) or more frequently in dusty conditions.
Valve Clearance Check:
Every 2000 km (1200 miles).
Chain Maintenance:
Lubricate and adjust chain every 500 km (300 miles).
Engine Oil Type:
Yamaha recommends Yamalube 4 (or equivalent SAE 10W-40 API SG or higher) motorcycle oil.
Engine Oil Capacity:
Approximately 0.95 Liters (1.0 US qt) without oil filter change, 1.0 Liter (1.1 US qt) with oil filter change. (Verify in manual)
Brake Fluid Type:
DOT 3 or DOT 4 hydraulic brake fluid.
Transmission Oil:
Engine oil is shared with the transmission in this design.
Common Wear Items:
Clutch plates (due to automatic clutch), chain and sprockets, front fork seals, carburetor jets (clogging).
Potential Problems:
Carburetor performance can be sensitive to altitude and fuel quality. Ignition coil or CDI unit failure is possible but less common than wear items.
Heritage:
Yamaha has a long and storied history in motorcycle manufacturing, renowned for innovation, performance, and reliability across all classes of motorcycles, from racing superbikes to off-road machines.
Evolution:
The TT-R line was introduced to offer a range of reliable and user-friendly off-road bikes. The TT-R90 served as a smaller displacement option, evolving from earlier smaller Yamaha dirt bikes, and paved the way for later models with electric start and slightly larger engines.
Production Years:
The TT-R90 was produced for several years, with the 2001 model being a key iteration in its lifecycle.
