2005–2006 Yamaha TT-R125 / TT-R125E / TT-R125LW / TT-R125LWE Owner's Service Manual (P/N 1B2-F8199-81)

Yamaha's Owner's Service Manual, publication 1B2-F8199-81, first edition (May 2005), covers the 2005–2006 TT-R125, TT-R125E, TT-R125LW and TT-R125LWE in their kick-start, electric-start and large-wheel configurations. Regional specification tables also identify the North American TT-R125L(V) and TT-R125LE(V) names.

Supplied as one 610-page PDF with English, French and German content.

• Engine repair: Cylinder-head and valve service, camshaft and rocker-arm inspection, piston replacement, crankcase separation, crankshaft installation and balancer alignment.

• Clutch and transmission: Friction-plate inspection, clutch adjustment, primary-drive service, and removal and assembly of the transmission, shift cam and shift forks.

• Carburetor and lubrication: Mikuni VM20SS disassembly, coasting-enricher inspection, fuel-level adjustment, oil-pump inspection and rotary-filter service.

• Brakes and chassis: Drum-brake service, large-wheel front-disc overhaul and bleeding, front-fork repair, steering-bearing work and swingarm-linkage inspection.

• Electrical diagnosis: CDI magneto tests, starting-circuit checks, starter-motor repair and charging-system fault tracing, with separate coverage for electric-start models.

• Scheduled maintenance: Pre-ride inspections, valve-clearance checks, throttle adjustment, air-filter service, drive-chain inspection and lubrication schedules.

• Illustrated procedures: Exploded diagrams and job instruction charts identify parts and removal scope; cable-routing diagrams and sectional views support assembly.

Owners can use the operating and basic-maintenance sections; Yamaha presents the repair procedures as a mechanic's reference requiring the appropriate special tools.

Engine, Carburetor and Transmission Repair

Internal-engine coverage includes valve-guide replacement and seat lapping, timing-chain installation and crankshaft inspection. The cylinder-mark/piston-color matching chart helps select the correct piston group before a cylinder-and-piston repair.

The crankcase procedure warns against forcing the case halves apart or striking gasket faces, which can damage the sealing surfaces.

Transmission drawings identify the three shift-fork positions and their guide-bar arrangement.

Carburetor coverage includes float-valve inspection, coasting-enricher diaphragm checks and the documented high-altitude main-jet option.

Brake and Suspension Variants

Drum-front-brake procedures apply to TT-R125/TT-R125E; front-caliper, master-cylinder and bleeding procedures apply to TT-R125LW/TT-R125LWE. All four use a rear drum brake.

The TT-R125LWE has separate fork-preload and rear-shock compression/rebound adjustments. Fork sections cover damper-rod and seal work; Yamaha recommends dealer maintenance for this assembly.

Damper-rod handling notes explain how the rod can be damaged if it drops inside the fork tube.

Rear-shock coverage includes external adjustment, removal, inspection and replacement. It does not include internal overhaul of the nitrogen-charged damper.

Ignition, Starting and Charging Diagnosis

The wiring section distinguishes kick-start and electric-start circuits. Ignition, no-crank and charging troubleshooting flowcharts link symptoms to switch, relay, coil and wiring checks.

The starting circuit cut-off schematic explains the clutch/neutral interlock, helping distinguish an interlock fault from a starter-motor problem. Starter-motor work includes armature insulation, commutator and brush inspection.

Battery-charging charts distinguish variable-voltage and constant-voltage chargers.

Specifications and Special Tools

VIN, engine-number and model-label locations support machine identification before ordering parts.

Reference data includes camshaft runout, valve-seat widths and piston clearances. Fluid capacities, wear limits, electrical test values and component-specific torque tables accompany the repair information.

The tool list distinguishes regional part numbers, including crankcase separator YU-1135-A / 90890-01135 and flywheel puller YU-33270-B / 90890-01362.

Observe Yamaha's safety precautions for brake service, battery charging and hot engine parts.

PDF Navigation and Diagram Readability

The total includes front and back covers (2 pages), five memo pages and two blank pages. Bookmarks cover all six chapters and subsections in the three languages; the main text supports search, but some wiring labels, cable-routing text and battery-charging charts do not. Small labels in the wiring diagrams require zooming.