2004 Yamaha YZ125T1 Owner's Service Manual PDF (P/N LIT-11626-18-33)

Yamaha's Owner's Service Manual covers the 2004 YZ125T1 for the USA and Canada, YZ125 for Europe and South Africa, and YZ125T for Australia and New Zealand. This is the first edition, May 2004, P/N LIT-11626-18-33; the cover also carries document code 1C3-28199-10.

• Engine repair: Engine removal, cylinder-head and piston inspection, YPVS power-valve and governor service, crankcase separation, and crankshaft removal and installation.

• Clutch and transmission: Clutch and primary driven gear repair, kick axle and shift shaft service, transmission inspection, and shift cam and fork assembly.

• Fuel and cooling: Carburetor disassembly, reed-valve inspection, fuel-level adjustment, radiator pressure testing, and water-pump seal and bearing replacement.

• Chassis and suspension: Brake caliper and master-cylinder repair, front-fork rebuilding, steering and swingarm bearing service, and rear-shock spring and bearing work.

• Ignition diagnosis: CDI magneto service, ignition-timing checks, wiring and cable-routing diagrams, and an ignition-system inspection flowchart with electrical tests.

• Maintenance and tuning: Race-based maintenance charts, carburetor setting-parts and symptom tables, sprocket selection, and suspension adjustments for track conditions.

Owners can use the operating and maintenance sections; the repair chapters are suited to qualified mechanics with the specified tools, and Yamaha recommends dealer maintenance for the front fork.

Piston Matching, YPVS and Internal Engine Repair

The piston-and-cylinder combination chart matches cylinder grades A-D to piston markings and colors, helping identify the intended fit before selecting replacement parts. The cylinder section expressly prohibits reboring.

Crankshaft inspections cover runout, connecting-rod play and crank width. Exploded views and job charts show power-valve components, transmission assemblies and shift-fork positions. Special-tool references include the crankcase separating tool YU-1135-A / 90890-01135.

Carburetor Tuning and Cooling-System Service

Carburetor setting-parts charts list jets, needles and part numbers, with separate European settings. Symptom tables and throttle-opening charts connect mixture adjustments to engine behavior, while atmospheric-condition guidance supports track setup. Test runs and spark-plug checks are part of the tuning assessment.

The venturi block and main nozzle are not intended for disassembly; the manual warns that dismantling them can reduce carburetor performance.

Cooling coverage includes radiator-cap testing, system leak checks and impeller-shaft inspection. Water-pump assembly notes identify the risk of damaging the seal lip or dislodging its spring during shaft installation.

Fork Rebuilding, Rear-Shock Limits and Chassis Work

Front-fork exploded views accompany damper and base-valve inspection, seal replacement, oil filling and air bleeding. The listed fork seal driver is YM-01442 / 90890-01442. A specific assembly caution explains how a dropped damper assembly can damage the valve inside the fork.

Rear-shock coverage: Removal, spring replacement, mounting-bearing service and damping adjustments are included. Internal rebuilding of the pressurized damper cylinder and nitrogen tank is excluded; leaking units are replaced as assemblies.

Suspension-setting charts relate handling symptoms to springs, damping and front/rear balance. Brake chapters cover hydraulic components and bleeding, while steering and swingarm sections address bearing inspection and replacement.

Support the machine securely during engine and chassis removal, and let the engine and radiator cool before opening the cooling system.

CDI Ignition Fault Tracing

The ignition inspection flowchart separates connection faults, stop-button operation, spark-plug cap problems, ignition-coil faults and CDI magneto faults before CDI-unit replacement. The wiring diagram, connector views and test-lead illustrations support the individual checks.

Examples of Fluid Capacities, Fastener Torques and Inspection Data

These are a small selection of the manual's service and test specifications. The cylinder-head warpage limit is 0.03 mm.

Transmission oil capacity for a periodic change is 0.66 L. Coolant capacity is 0.9 L, including all cooling-system routes.

Reassembly references specify 145 Nm for the steering shaft nut and 80 Nm for the clutch boss nut. The steering bearing's ring-nut adjustment is a separate procedure.

For ignition diagnosis, source coil 1 resistance is 720-1,080 ohms at 20°C (68°F), measured between the Black/Red and Green/White leads.

PDF Search, Bookmarks and Page Breakdown

Text navigation and diagram detail: The main manual text is searchable, and embedded bookmarks cover the chapters and major sections. The warning page and lettering within some diagrams are not searchable. Small wiring and connector labels are readable when enlarged.

One printable English PDF contains 259 pages: 243 pages of technical chapters, 14 preliminary pages including the warning page, and two covers. All are included in the total.