Honda TRX250EX / TRX250X ATV Service Manual, 2006–2011

This Honda service manual covers the 2006–2011 TRX250EX and TRX250X ATVs, with maintenance, troubleshooting, and internal engine and drivetrain repair procedures.

Searchable Text, Chapter Bookmarks and Diagram Detail

Search and diagram access: The workshop text has an OCR search layer and embedded chapter bookmarks. Recognition errors can affect exact-word searches. Small wire-color codes and connector labels in the wiring diagrams are readable when enlarged.

One printable, English-language PDF contains 369 pages, including the cover, three preliminary pages, and nine memo pages.

Engine, SportClutch and Chassis Service

These selected workshop topics highlight the manual’s repair and diagnostic coverage. Other included subjects range from body-panel and exhaust removal to spark-arrester cleaning.

• Engine repair: Engine removal and installation, cylinder-head disassembly, valve-guide replacement, valve-seat refacing, piston inspection, and camshaft service.

• Fuel and lubrication: Carburetor disassembly, pilot-screw adjustment, high-altitude jetting, oil-pump inspection, relief-valve service, and oil-cooler removal and installation.

• SportClutch and transmission: Centrifugal and change-clutch overhaul, gearshift-linkage service, crankcase separation, and internal gearbox inspection.

• Shaft drive: Rear-axle removal, final-drive disassembly, bearing replacement, gear-backlash inspection, and tooth-contact-pattern checks.

• Brakes and chassis: Front hydraulic brake bleeding, master-cylinder and caliper repair, rear drum-brake service, suspension-bearing replacement, and steering repairs.

• Electrical diagnosis: Charging and ignition tests, starter-motor overhaul, relay and switch checks, system diagrams, and model-specific wiring diagrams.

Honda wrote this manual for qualified professional technicians and specifies dedicated tools and equipment for some procedures.

Engine, Carburetor and Lubrication Work

Step-by-step procedures extend to valve-guide replacement and valve-seat refacing. The rocker arms, cylinder head, valves, cylinder/piston, and camshaft can be serviced with the engine installed; transmission and crankshaft service require engine removal and crankcase separation.

The PDC1G carburetor section details main and slow jet identification, float-valve inspection, and idle-drop pilot-screw adjustment. High-altitude modifications and restoration of the original low-altitude settings receive separate treatment.

For the air-cooled engine’s lubrication system, the manual provides oil-pump clearance checks, relief-valve inspection, and oil-cooler leak and obstruction checks. The Lubrication System Diagram shows how oil reaches the engine’s working components.

SportClutch, Gearbox and Final-Drive Rebuilds

Clutch inspection covers the one-way mechanism, weight linings, discs, plates, springs, and lifter bearing. Gearbox data extend to gear bushings, shaft wear, shift-fork dimensions, and shift-drum condition.

Reassembly cautions: The centrifugal-clutch locknut has left-hand threads, with specific precautions against crankshaft-thread damage. Final-drive instructions also warn that an excessively thick ring-gear shim can lock the gears under light tightening.

Gear Tooth Contact Pattern illustrations accompany the final-drive shim-selection and backlash procedures. Torque information distinguishes actual torque from indicated wrench readings when the specified locknut tools change the wrench’s leverage.

Steering Repairs and Electrical Fault Isolation

Steering coverage includes ball-joint replacement, steering-shaft bearing replacement, and toe adjustment. Rear suspension procedures extend to swingarm pivot bearings and rear-axle bearings. Rear-brake instructions also cover the brake cam, cables, and parking-brake adjustment.

Electrical checks address alternator charging-coil resistance, regulator/rectifier wiring, ignition-coil and CKP-sensor peak voltage, and starter-relay circuits. Symptom-based troubleshooting connects starting difficulties, power loss, and poor running with the relevant fuel, ignition, and compression checks, helping technicians select the appropriate inspection before disassembly.

Variant-specific references: Separate wiring diagrams distinguish 2006–2007 models from models after 2007. Cable & Harness Routing drawings, crankcase-emission-control illustrations, and charging-system diagrams provide additional component and connection references.

Follow the manual’s vehicle-support and electrical-isolation precautions during engine and chassis disassembly.

A Preview of Valve and Carburetor Settings

Valve adjustment: Intake and exhaust valve clearance is specified at 0.13 mm (0.005 in) with the engine cold, below 35°C (95°F). The maintenance section covers the associated screw-and-locknut adjustment.

Carburetor inspection: The float-level specification is 14 mm (0.55 in), measured with the float valve seated and the float arm just touching it. The float is nonadjustable; the manual specifies float-assembly replacement when the level is outside specification.