1987 Honda TRX350D Service Manual
The 1987 Honda TRX350D is a four-wheel ATV featuring a 350cc four-stroke engine, electric start, shaft drive, independent rear suspension, dual-range transmission, reverse gear, front and rear hydraulic disc brakes, and full instrumentation. This manual covers maintenance procedures, specifications, troubleshooting, and repair instructions for proper servicing and operation.
General Information
This manual provides technical information for the 1987 Honda TRX350D four-wheel ATV. Includes identification numbers, safety precautions, and general maintenance guidelines.
| Component | Location |
|---|
| Vehicle Identification Number | Right side of frame near steering head |
| Engine Serial Number | Right side of crankcase |
| Model Code | TRX350D |
| Manufacture Date | Stamped on VIN plate |
Specifications
- Engine Type: 350cc 4-stroke OHC single cylinder
- Bore x Stroke: 79.0mm x 71.5mm
- Compression Ratio: 8.5:1
- Carburetor: 28mm constant velocity
- Ignition System: CDI electronic
- Starting System: Electric with auxiliary recoil
- Transmission: 5-speed with reverse and dual-range sub-transmission
- Drive System: Shaft drive with independent rear suspension
- Front Suspension: Independent double wishbone
- Rear Suspension: Independent swingarm
- Brakes: Hydraulic disc front and rear
- Fuel Capacity: 3.7 gallons (14 liters)
- Dry Weight: 462 lbs (210 kg)
Periodic Maintenance
Regular maintenance schedule for optimal performance and longevity.
| Service Item | Interval | Procedure |
|---|
| Engine Oil Change | Every 100 hours or 6 months | Drain and refill with 10W-40 |
| Oil Filter | Every 200 hours or 12 months | Replace with genuine Honda filter |
| Air Filter | Every 50 hours | Clean and re-oil foam element |
| Spark Plug | Every 100 hours | Clean and gap to 0.028-0.031 in |
| Valve Clearance | Every 200 hours | Adjust to 0.004 in (0.10mm) |
| Front Differential Oil | Every 200 hours | Check and refill as needed |
| Brake Fluid | Every 2 years | Replace DOT 4 fluid |
Engine Service
Complete engine maintenance and repair procedures.
- Oil Change: Warm engine, remove drain plug, drain completely, refill with 2.4 quarts of 10W-40.
- Valve Adjustment: Remove valve cover, set engine to TDC compression, adjust intake and exhaust valves to 0.004 in.
- Cylinder Head: Torque bolts in sequence to 20 ft-lbs.
- Piston & Rings: Standard bore 79.0mm, oversize available.
- Timing Chain: Check tensioner operation, replace if stretched.
WARNING! Always disconnect battery before servicing electrical components.
Fuel System
Carburetor service and fuel delivery system.
- Carburetor Removal: Disconnect fuel line, throttle cable, and vent lines.
- Float Level: Set to 12.5mm from carburetor body.
- Main Jet: #122 (standard)
- Slow Jet: #38 (standard)
- Fuel Filter: Replace annually or if contaminated.
- Fuel Pump: Mechanical type, check for proper pressure.
Electrical System
Battery, charging, and ignition system specifications.
| Component | Specification |
|---|
| Battery | 12V 14Ah |
| Charging Output | 14V 15A at 5000 RPM |
| Spark Plug | NGK DR8ES-L |
| Ignition Timing | Fixed at 15° BTDC |
| Starter Motor | 0.8 kW |
| Fuses | Main 30A, Headlight 10A |
Drive System
Transmission, differential, and shaft drive maintenance.
- Transmission Oil: Change every 200 hours with 80W-90 gear oil.
- Front Differential: Check oil level monthly, refill with 80W-90.
- Drive Shaft: Lubricate U-joints every 100 hours.
- Sub-Transmission: Dual-range selector operation and adjustment.
- Reverse Gear: Engagement procedure and troubleshooting.
Suspension & Steering
Front and rear suspension service procedures.
- Front Shocks: Oil capacity 200cc per leg, spring preload adjustable
- Rear Shocks: Gas charged, rebound damping adjustable
- Wheel Alignment: Toe-in 0-10mm, camber non-adjustable
- Steering Stem: Check bearing play, torque to 35 ft-lbs
- Tire Pressure: Front 3.6 psi, Rear 3.6 psi (standard)
Brakes
Hydraulic disc brake maintenance and service.
- Brake Pads: Replace when worn to 1mm thickness.
- Brake Fluid: Use DOT 4, bleed system annually.
- Rotor Thickness: Minimum 3.5mm front, 4.0mm rear.
- Calipers: Clean and lubricate slide pins every 100 hours.
- Master Cylinders: Check for leaks, rebuild if necessary.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|
| Hard starting | Weak battery, dirty carburetor | Charge battery, clean carb jets |
| Overheating | Low coolant, clogged radiator | Check coolant level, clean fins |
| Poor performance | Clogged air filter, worn spark plug | Clean filter, replace plug |
| Transmission noise | Low oil level, worn gears | Check oil, inspect gears |
| Brake drag | Stuck caliper, contaminated fluid | Clean caliper, flush fluid |
| Electrical failure | Blown fuse, bad connection | Check fuses, clean connections |
Wiring Diagrams
Complete electrical schematics for the TRX350D including color codes and connector locations.
- Main Harness: Color-coded wiring with connector identification
- Ignition System: CDI unit, pulse generator, coil connections
- Charging System: Stator, regulator/rectifier, battery connections
- Lighting Circuit: Headlight, taillight, brake light wiring
- Starting System: Starter relay, solenoid, safety switches
Service Support: Contact Honda Customer Service at 1-866-784-1870 or visit www.ahm-ownerlink.com
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