1986 Honda TRX 250 Service Manual

The 1986 Honda TRX 250 is a four-wheel all-terrain vehicle featuring a 246cc four-stroke engine, 5-speed transmission with reverse, shaft drive system, front and rear suspension, hydraulic disc brakes, and electric start. This service manual covers maintenance procedures, specifications, troubleshooting, and repair instructions for proper servicing and operation of the ATV.

General Information

This manual provides technical information for the 1986 Honda TRX 250 ATV. Includes identification, safety precautions, and general maintenance guidelines.

Specifications

• Engine Type: 246cc air-cooled 4-stroke OHC
• Bore x Stroke: 66.0 x 72.0 mm
• Compression Ratio: 9.2:1
• Carburetor: 22mm piston valve
• Ignition System: CDI
• Starting System: Electric and auxiliary recoil
• Transmission: 5-speed with reverse
• Final Drive: Shaft
• Suspension: Front: Independent double wishbone, Rear: Swingarm
• Brakes: Front and rear hydraulic disc
• Tires: Front: 22x7-10, Rear: 22x11-10
• Fuel Capacity: 2.6 gallons

Periodic Maintenance

Regular maintenance schedule for optimal performance and longevity.

1. Engine Oil: Change every 100 hours or 6 months
2. Oil Filter: Replace with oil change
3. Air Filter: Clean every 50 hours, replace as needed
4. Spark Plug: Clean and gap every 100 hours
5. Valve Clearance: Check every 200 hours
6. Drive Shaft: Lubricate every 100 hours
7. Brake Fluid: Check level monthly, replace annually
8. Tire Pressure: Check before each use

WARNING! Always use Honda Genuine parts and recommended lubricants.

Engine Service

Engine disassembly, inspection, and reassembly procedures.

1. Cylinder Head Removal: Remove camshaft, valves, inspect for wear
2. Cylinder/Piston: Measure cylinder bore, piston clearance
3. Crankshaft: Check runout and bearing clearance
4. Camshaft: Inspect lobes for wear, check timing
5. Oil Pump: Disassemble and inspect for wear

Torque Specifications: Cylinder head bolts: 20 ft-lb, Connecting rod bolts: 14 ft-lb

Fuel System

Carburetor service and fuel system maintenance.

1. Carburetor Removal: Disconnect fuel lines and throttle cable
2. Float Level: Adjust to 12.5mm
3. Main Jet: #112 (standard)
4. Slow Jet: #38 (standard)
5. Fuel Filter: Replace annually or when clogged
6. Fuel Tank: Inspect for rust and clean as needed

CAUTION! Use clean fuel and avoid ethanol blends when possible.

Electrical System

Battery, charging system, ignition, and lighting.

Drive System

Transmission, clutch, and final drive service.

1. Transmission Oil: Change every 200 hours
2. Clutch Adjustment: Adjust free play at lever
3. Drive Shaft: Inspect universal joints for wear
4. Front Differential: Check oil level monthly
5. Rear Gearcase: Change oil every 200 hours

Transmission Oil Capacity: 1.5 quarts SAE 10W-40

Suspension & Brakes

Front and rear suspension, steering, and brake systems.

1. Front Suspension: Check ball joints and bushings
2. Rear Suspension: Inspect swingarm bearings
3. Shock Absorbers: Check for oil leaks
4. Brake Pads: Replace when worn to 1mm thickness
5. Brake Fluid: DOT 4, bleed system annually
6. Steering: Check for play and adjust as needed

Troubleshooting

Wiring Diagrams

Complete electrical schematics for the 1986 TRX 250. Includes color-coded wiring, connector locations, and component identification for proper electrical system diagnosis and repair.

Service Information: Contact Honda Customer Service at 1-866-784-1870 or visit www.honda.com