1985–1987 Honda FourTrax 250 / TRX250 ATV Service Manual (P/N 61HA802)

This Honda service manual (P/N 61HA802) covers the 1985–1987 FourTrax 250 / TRX250 ATV, with separate '85 and after-'85 service details for the engine, chassis and electrical systems.

• Engine repair: Engine removal and installation, cylinder-head and valve service, camshaft timing, cam-chain tensioner work, and cylinder/piston inspection.

• Clutch and transmission: Centrifugal and manual clutch repair, kick-starter service, gearshift linkage inspection, crankcase separation, crankshaft checks, and transmission disassembly.

• Fuel and lubrication: Dual-valve carburetor overhaul, throttle-valve synchronization, pilot-screw and high-altitude adjustments, plus oil-pump, filter and screen servicing.

• Chassis and final drive: Kingpin and knuckle-bushing replacement, steering-stem service, shock disassembly, swing-arm bearing replacement, and final-drive gear setup.

• Brake service: Front hydraulic drum-brake bleeding, wheel-cylinder and master-cylinder inspection, rear cable-operated drum-brake service, and lining wear limits.

• Electrical diagnosis: CDI ignition, alternator and charging tests, starter-circuit checks, oil-temperature warning troubleshooting, and separate model-year wiring diagrams.

Suited to technicians and mechanically proficient owners equipped for the work. Honda's maintenance schedules reserve some tasks for authorized dealers, and the manual assumes familiarity with standard workshop procedures.

Engine, Clutch and Transmission Repair

Top end and lubrication: The cylinder-head chapter covers valve-guide replacement, valve-seat refacing and camshaft installation. Cylinder and piston inspection includes ring-groove clearance and wear-limit tables, while the lubrication diagram traces oil through the pump, filter and engine shafts.

Internal drivetrain: Crankshaft and transmission repair requires crankcase separation. Exploded-view assemblies distinguish the manual clutch, centrifugal clutch, starter clutch and kick-starter mechanism; gearshift linkage service includes the shift drum, return spring and shifter pawls.

The centrifugal clutch lock nut has left-hand threads; forcing it in the usual loosening direction can damage the threads.

Carburetor and Routine Maintenance

The dual-valve carburetor section explains the relationship between the butterfly and piston throttle valves, with synchronization checks after assembly. High-altitude adjustment is treated separately from standard settings.

Maintenance schedules distinguish '85 and after-'85 versions and call for more frequent service in wet or dusty conditions. Engine-oil and filter changes, final-drive oil servicing, clutch adjustment, reverse-lock cable checks and spark-arrester cleaning are included.

Steering, Brakes and Gearcase Setup

Alignment coverage includes toe-in adjustment and camber/caster checks; the latter angles are not adjustable. Separate output-gear and final-drive sections provide shim or spacer selection, backlash measurements and gear-tooth contact pattern illustrations. The contact-pattern and backlash checks help evaluate gear mesh after bearings or gears have been replaced.

Brake specifications distinguish front wheel-cylinder work from rear brake-cam and cable service. Always verify the vehicle is securely supported on appropriate stands and the exhaust is completely cool before starting inspection or teardown.

Ignition, Charging and Fault Isolation

Electrical reference material includes the ignition schematic, cable-and-harness routing drawings and switch-continuity charts. The no-start and low-power troubleshooting charts connect fuel supply, compression and ignition checks with probable causes, helping narrow the fault before component replacement.

The starter chapter describes Mitsuba motor maintenance and also lists separate ND brush specifications. CDI test tables require the specified test equipment; the manual notes that an unsuitable tester can give false readings.

The oil-temperature warning circuit has separate fault paths for a lamp that stays on and one that fails to light. Interchanging the neutral switch's light green/red wire and the reverse switch's gray wire can indicate neutral while reverse is engaged, creating an unexpected-reversing hazard.

A Preview of Compression and Valve-Service Data

These examples are a small selection of the maintenance and cylinder-head specifications. The maintenance chapter specifies compression pressure of 12.5 ± 1.0 kg/cm² (178 ± 14 psi) for a warm engine cranked with the throttle fully open.

Intake and exhaust valve clearance is 0.08 mm (0.003 in) with the engine cold, below 35°C (95°F). Cylinder-head cap nuts have a 35–45 N·m (25–33 ft-lb) specification, separate from the socket-bolt specification.

Searchable Service Text and Wiring-Diagram Bookmarks

Search, navigation and diagram detail: Most service text is searchable, although OCR errors affect some terms and wiring labels. Chapter and wiring-diagram bookmarks are included; small wiring labels require zooming. Cover and safety-notice text is not searchable.

One printable, English-language PDF with 233 pages total. The cover, safety notice, contents page and seven memo pages are already included in that total.