1986 TRX250R Service Manual

The 1986 Honda TRX250R is a high-performance sport ATV featuring a liquid-cooled 246cc two-stroke engine, Pro-Link rear suspension, and manual 6-speed transmission. This service manual covers maintenance procedures, specifications, troubleshooting, and repair instructions for the complete ATV system including engine, chassis, electrical, and suspension components.

1. General Information 2. Specifications 3. Periodic Maintenance 4. Engine Service 5. Fuel System 6. Electrical System 7. Chassis & Suspension 8. Transmission & Drive 9. Brake System 10. Troubleshooting 11. Wiring Diagrams

General Information

This manual provides complete service information for the 1986 Honda TRX250R. Includes safety precautions, tool requirements, and general maintenance procedures.

ComponentDescription
ModelTRX250R
Year1986
TypeSport ATV
Engine246cc liquid-cooled 2-stroke
Transmission6-speed manual
Final DriveChain
Suspension FrontIndependent double wishbone
Suspension RearPro-Link swingarm

Specifications

Periodic Maintenance

Regular maintenance schedule and procedures to ensure optimal performance and longevity.

  1. Engine oil change: Every 6 months or 500 miles
  2. Air filter cleaning: Every 3 months or 250 miles
  3. Spark plug replacement: Every 12 months or 1,000 miles
  4. Chain adjustment: Every 200 miles
  5. Brake fluid change: Every 2 years
  6. Coolant replacement: Every 2 years

WARNING! Always use genuine Honda parts and recommended fluids. Follow torque specifications precisely.

Engine Service

Complete engine disassembly, inspection, and reassembly procedures.

  1. Cylinder head removal and installation
  2. Cylinder and piston service
  3. Crankshaft and connecting rod inspection
  4. Reed valve service
  5. Water pump repair
  6. Exhaust system maintenance

CAUTION! Engine must be completely cool before disassembly. Use proper sealing compounds during reassembly.

Fuel System

Carburetor service, fuel tank maintenance, and fuel line procedures.

ComponentSpecification
Carburetor Type34mm PJ
Main Jet#165
Pilot Jet#58
Needle Clip Position3rd groove
Float Level12.5mm
Fuel PressureGravity feed

Electrical System

Complete electrical system diagnosis and repair procedures.

  1. CDI ignition system testing
  2. Stator and flywheel service
  3. Lighting system repair
  4. Starting system maintenance
  5. Battery service (if equipped)
  6. Wiring harness inspection

Tip: Always disconnect battery before electrical work. Use multimeter for proper diagnosis.

Chassis & Suspension

Frame, suspension components, and steering system service.

Transmission & Drive

Transmission, clutch, and final drive system service procedures.

  1. Clutch disassembly and inspection
  2. Transmission gear service
  3. Shift mechanism repair
  4. Drive chain adjustment and replacement
  5. Sprocket service

WARNING! Transmission work requires complete engine disassembly. Follow factory service procedures exactly.

Brake System

Hydraulic disc brake maintenance and repair procedures.

ComponentSpecification
Brake Fluid TypeDOT 4
Front Disc Diameter174mm
Rear Disc Diameter190mm
Pad Thickness (min)1.5mm
Rotor Thickness (min)3.0mm

Troubleshooting

SymptomPossible CauseCorrective Action
Hard startingFouled plug, stale fuelReplace spark plug; drain old fuel; check compression
Poor performanceClogged carb, air leakClean carburetor; check reed valve; inspect base gasket
Transmission noiseWorn gears, low oilCheck oil level; inspect transmission gears
OverheatingLow coolant, water pumpCheck coolant level; inspect water pump impeller
Electrical failureBad stator, CDI unitTest stator output; check CDI unit; inspect wiring

Wiring Diagrams

Complete electrical schematics and wiring diagrams for the 1986 TRX250R. Includes color-coded wiring, connector locations, and component identification.

Service Support: For technical assistance or genuine parts, contact authorized Honda dealership or visit Honda's official service website.

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