2004–2007 Honda CR125R Factory Service & Repair Manual (P/N 61KSR03)

This Honda factory service manual covers the 2004–2007 CR125R, with separate procedures and specifications for 2004 and later models.

• Engine repair: Engine removal and installation, cylinder-head inspection, cylinder and piston replacement, crankcase splitting, crankshaft inspection, and bearing replacement.

• Clutch and transmission: Clutch inspection and assembly, kickstarter rebuilding, gearshift linkage service, and mainshaft, countershaft, shift-fork, and shift-drum inspection.

• RC valve: Exhaust-valve decarbonizing, shaft inspection, servo-motor and cable diagnosis for 2004, and governor/valve-linkage service for later models.

• Fuel system: Carburetor disassembly and assembly, temperature-and-altitude tuning charts, throttle position sensor adjustment, reed-valve service, and air-cleaner maintenance.

• Cooling system: Radiator-cap and system pressure testing, coolant replacement and air bleeding, radiator removal, and water-pump bearing and seal replacement.

• Suspension and brakes: Fork and shock-absorber overhaul, swingarm and linkage bearing replacement, steering-stem service, hydraulic brake bleeding, and master-cylinder and caliper rebuilding.

• Electrical diagnosis: Ignition and alternator testing, connector references, model-specific wiring diagrams, cable-routing drawings, and troubleshooting charts for starting and performance faults.

This manual is suited to experienced mechanics equipped for internal engine work, precision measurement, and suspension service with dedicated pullers and bearing tools.

Engine, Clutch and Crankcase Work

Race-based maintenance schedules accompany VIN and engine-number location illustrations, engine and frame torque tables, and lubrication-point references. Frame, body-panel, subframe, and exhaust removal procedures provide access for the mechanical work.

The top-end section explains A/B cylinder and piston matching, ring inspection, and cylinder-to-piston clearance checks. It identifies a specific assembly hazard: rotating the cylinder during installation can catch and break the piston ring at a cylinder port.

Crankshaft and transmission service requires engine removal; cylinder, piston, clutch, kickstarter, and gearshift-linkage work can be performed with the engine installed. Transmission exploded views identify gear, bushing, washer, and snap-ring positions, while the crankcase section specifies the puller and assembly tools.

RC Valve Versions and Fault Tracing

The 2004 troubleshooting sequence separates cable movement, carbon-related valve sticking, servo operation, potentiometer checks, and harness continuity. This helps narrow the cause of an RC valve that will not operate before treating it as a failed servo.

Later models use the governor and valve linkage, with procedures for the tie rod, pinion gear, and governor-shaft bearings. The governor itself is handled as an assembly; internal governor disassembly is expressly excluded.

Carburetor Tuning and Water-Pump Service

The fuel-system specifications distinguish the TMX04A carburetor for 2004 from the TMX05A for later models. Separate Carburetor Tuning Charts relate jetting to temperature and altitude, with additional guidance for track conditions and throttle-range symptoms.

Cooling coverage includes the Coolant Gravity Chart and separate component layouts for the two model groups. Water-pump procedures extend to shaft inspection and replacement of the bearings, water seal, and oil seal.

Fork, Shock and Hydraulic Brake Repairs

Fork procedures cover the damper, bladder, bushings, seals, and fluid filling. The manual warns that overtightened fork pinch bolts can deform the outer tubes and make replacement necessary.

Shock service includes bladder replacement, damper-rod disassembly, valve-stack handling, and air bleeding. Detailed rider-weight preload and damping setup is referred to the separate Owner's Manual. The pressurized nitrogen reservoir requires the specific safety precautions described in the shock-service section.

Brake coverage extends beyond pads and fluid to piston cups, caliper seals, slide pins, and fault diagnosis for dragging or spongy brakes.

Ignition Tests and Wiring References

Electrical testing distinguishes the 2004 ECM and regulator/rectifier arrangement from the later ICM and exciter-coil system. Peak-voltage and resistance checks compare component and harness readings to help separate component faults from connection problems.

Separate wiring diagrams show the two configurations. Cable & Harness Routing drawings supplement the connector illustrations used in the diagnostic procedures.

Oil, Fastener and Ignition Specification Preview

The transmission oil-change section specifies 0.57 liter after draining and 29 N·m for the drain bolt. Cylinder-head installation includes staged tightening with a final nut torque of 27 N·m.

Ignition timing is specified as 30° ± 2° BTDC at 3,000 rpm for 2004, and 33.7° ± 2° BTDC at 4,000 rpm for later models. The timing check uses a warmed engine with the throttle position sensor disconnected.

Bookmarks, Text Search and PDF Contents

Search and diagram detail: An existing OCR text layer supports searches, but recognition errors can cause missed terms, particularly in diagram labels. Embedded bookmarks link to the contents, numbered sections, and both wiring diagrams. Small wiring labels require zooming, and fine lettering remains soft.

One printable English PDF contains 351 pages, including the cover, two introductory pages, and eight memo pages. Its 17 numbered sections include the index.