Model Years Covered:
1987, 1988, 1989, 1990, 1991, 1992, 1993
Chassis Codes:
2RM, 2RN, 2RW, 2RX, 3ET, 3KC
Segment:
Lightweight Sportbike / Supersport (125cc class)
Key Rivals:
Honda NSR125R, Suzuki RG125 Gamma, Aprilia RS125, Cagiva Mito 125.
Technological Highlights:
YPVS (Yamaha Power Valve System) for improved power delivery, liquid cooling, advanced chassis design for its class, aggressive styling.
Intended Users:
Yamaha TZR125 owners, mechanics, restorers, hobbyists requiring detailed service and repair information.
Engine Mechanical:
Engine assembly, disassembly, inspection, tuning, lubrication, cooling system, fuel system (carburetor, ignition), exhaust system.
Chassis And Suspension:
Frame, front fork (telescopic, damping, seals), rear suspension (monoshock, linkage, adjustments), steering system, wheels, tires, brakes (front and rear disc, hydraulic system, calipers, master cylinders).
Electrical System:
Wiring diagrams, ignition system, lighting, charging system (stator, regulator/rectifier, battery), starter motor, indicators, horn, fuses, troubleshooting.
Bodywork And Trim:
Fairings, seat, fuel tank, fenders, graphics, fasteners, removal and installation procedures.
Maintenance:
Scheduled maintenance, fluid changes (oil, coolant, brake fluid), filter replacements, chain adjustment, spark plug replacement, valve clearance check (if applicable to 2-stroke tuning), general inspection.
Repair And Rebuild:
Complete engine rebuilds, carburetor overhaul, brake system repairs, suspension component replacement, electrical component diagnosis and repair, bodywork repair.
Troubleshooting:
Diagnostic procedures for common and uncommon faults, problem identification, step-by-step troubleshooting guides for electrical and mechanical issues.
Depth:
Comprehensive, covering everything from basic maintenance to complete engine and chassis overhauls. Designed for both professional technicians and experienced DIY enthusiasts.
Printability:
Full Printable
Delivery Method:
Instant Download (No physical binding, digital delivery)
Digital Medium:
Digital file (for display on screen or print on demand)
Reader Software:
Adobe PDF Reader
Extraction Software:
WinRAR (or compatible archive utility)
Operating Systems:
All versions of Windows and Mac OS
Type:
2-Stroke, Liquid-Cooled, Single-Cylinder
Bore X Stroke:
56.4 mm x 50.0 mm (typical, may vary slightly by sub-model)
Compression Ratio:
7.2:1 (typical, for unleaded fuel)
Horsepower:
Approx. 20-30 PS (14.7-22 kW) at 10,000-11,000 RPM (depending on market regulations and specific model variant)
Torque:
Approx. 15-18 Nm at 9,500-10,500 RPM (depending on market regulations and specific model variant)
Carburetor:
Mikuni VM28SS (or similar 28mm slide carburetors)
Fuel Type:
Unleaded gasoline (minimum 91 RON)
System:
Premix or Autolube (Yamaha Hand-o-Matic oil injection system)
Type:
CDI (Capacitor Discharge Ignition)
Coolant Type:
Yamaha Hi-Performance All-Season Motorcycle Coolant or equivalent (50/50 mix of ethylene glycol and distilled water)
Braking System:
Front: Hydraulic Disc (270mm), Rear: Hydraulic Disc (210mm)
Tires Front:
100/80-17 M/C 52S (tubeless)
Tires Rear:
120/80-17 M/C 61S (tubeless)
Lighting:
Halogen Headlight, LED Tail Light (depending on sub-model variant)
Instrument Cluster:
Analog speedometer, tachometer, coolant temperature gauge, neutral indicator, turn signal indicators, high beam indicator.
Ypvs System:
Yamaha Power Valve System (YPVS) controlled by a servo motor to optimize exhaust port timing for improved torque and power across the RPM range.
Diagnostic Ports:
Not applicable for this era; diagnosis relies on visual inspection, physical checks, and interpretation of symptoms.
Oil Change:
Every 3,000 km or 6 months (refer to manual for specific gearbox oil)
Spark Plug Inspection:
Every 2,000 km
Air Filter Cleaning:
Every 3,000 km
Chain Lubrication Adjustment:
Every 1,000 km or after riding in wet conditions
Brake Fluid:
DOT 3 or DOT 4 (refer to manual for specific recommendation)
2-Stroke Oil:
Yamalube 2R or equivalent high-quality 2-stroke oil (specifically for premix or autolube system)
Common Problems:
Carburetor tuning sensitivity, wear on YPVS mechanism, aging electrical components (e.g., regulator/rectifier), front fork seal leaks, exhaust port blockages due to 2-stroke residue.
Legacy:
Yamaha's long history of producing performance-oriented motorcycles, particularly in the sportbike and racing segments.
Tzr Lineage:
Part of Yamaha's renowned TZR series, known for its 2-stroke performance and Grand Prix inspired styling, following earlier models like the TZR250.
Manufacturing Era:
Popular in the late 1980s and early 1990s, representing Yamaha's entry into the competitive 125cc supersport class.
