1986 Honda ATC 250R Service Manual

The 1986 Honda ATC 250R is a high-performance three-wheel all-terrain vehicle featuring a 248cc two-stroke engine, 5-speed transmission with manual clutch, front and rear suspension, front disc brake, rear drum brake, and rugged off-road capabilities. This service manual provides comprehensive technical information for maintenance, repair, and troubleshooting procedures. Below are key sections covering specifications, maintenance schedules, engine service, chassis repair, electrical systems, and troubleshooting.

Specifications

Technical specifications for the 1986 Honda ATC 250R all-terrain vehicle.

Maintenance Schedule

Recommended maintenance intervals for optimal performance and longevity.

1. Engine Oil: Change every 6 months or 500 miles
2. Air Filter: Clean every 3 months or 250 miles
3. Spark Plug: Replace every 12 months or 1,000 miles
4. Chain Adjustment: Check every month or 100 miles
5. Brake Inspection: Monthly visual inspection
6. Wheel Bearings: Lubricate every 6 months
7. Suspension: Check for leaks monthly

WARNING! Always perform maintenance in well-ventilated area. Use proper safety equipment.

Engine Service

Procedures for engine maintenance, repair, and overhaul.

1. Cylinder Head Removal: Remove mounting bolts in crisscross pattern
2. Piston Replacement: Measure ring end gap; align arrow toward exhaust
3. Crankcase Splitting: Mark cases before separation
4. Crankshaft Inspection: Check runout and bearing play
5. Reed Valve Service: Inspect for cracks or warping
6. Cooling System: Clean fins regularly for proper heat dissipation

CAUTION! Engine components are precision parts; handle with care to avoid damage.

Chassis & Suspension

Frame, suspension, and steering component service procedures.

• Frame Inspection: Check for cracks at stress points
• Front Fork Service: Replace seals if leaking; check spring tension
• Rear Shock Service: Adjust preload; inspect bushings
• Steering Stem: Check bearing play; adjust as needed
• Swingarm: Lubricate pivot points regularly
• Fasteners: Torque to factory specifications

Electrical System

Wiring, ignition, lighting, and charging system maintenance.

Components: CDI unit, stator, spark plug, voltage regulator, battery, lighting coil.

Testing Procedures: Check resistance values; inspect wiring for damage; verify ground connections. Use multimeter for voltage and continuity tests. Replace damaged wiring immediately.

Fuel System

Carburetor service and fuel delivery system maintenance.

1. Carburetor Cleaning: Disassemble; clean jets with compressed air
2. Float Level Adjustment: Set to 18.5mm specification
3. Fuel Line Inspection: Check for cracks or deterioration
4. Fuel Filter: Replace if clogged
5. Mixing Ratio: Use 32:1 fuel/oil ratio with 2-stroke oil

Tip: Always use fresh fuel; drain carburetor for long-term storage.

Transmission & Clutch

Gearbox, clutch, and drive chain service procedures.

1. Clutch Adjustment: Set free play at lever to 10-20mm
2. Transmission Oil: Change every 12 months or 1,000 miles
3. Gear Inspection: Check for worn or chipped teeth
4. Shift Mechanism: Verify proper engagement of all gears
5. Chain Adjustment: Maintain 1-1.5 inches of free play
6. Sprocket Inspection: Replace if teeth are hooked

WARNING! Transmission contains small parts; work on clean surface to avoid loss.

Brake System

Front disc brake and rear drum brake maintenance.

Front Disc Brake: Check pad thickness; replace if below 1mm. Bleed system if spongy. Rear Drum Brake: Adjust cable tension; inspect shoes for wear.

Wheels & Tires

Wheel bearing service and tire maintenance procedures.

Wheel Bearing Replacement: Remove axle; press out old bearings; install new bearings with proper seals. Tire Pressure: Maintain 3.5 psi for standard terrain conditions.

Troubleshooting

Service Note: Always refer to torque specifications in manual. Use genuine Honda parts for best performance.

Support: Contact authorized Honda dealer for technical assistance.