Honda TRX250 Fourtrax ATV 1985-1987 - Comprehensive Service Manual

Honda TRX250 Fourtrax ATV Service Manual (1985-1987)

Master the maintenance and repair of your classic Honda ATV with this definitive, professional-grade service manual. Covering the legendary TRX250 Fourtrax models produced between 1985 and 1987, this guide is the ultimate resource for owners, restorers, and mechanics who demand factory-accurate technical data.

This manual provides comprehensive coverage for the 246cc air-cooled 4-stroke engine and the specialized semi-double cradle chassis that made the Fourtrax a pioneer in the ATV industry.

Complete Model Coverage & Specifications

The guide includes specific data for the original 1985 release and updated specifications for the '86-'87 ("After '85") models:

• Engine Performance: Single cylinder inclined at 20°, delivering 19.3 HP @ 7,000 rpm (SAE).
• Transmission: 5-speed constant mesh with reverse, featuring a dual-clutch system (wet multi-plate semi-automatic and centrifugal).
• Chassis Dimensions: Overall length of 1,875 mm (73.8 in) with a robust dry weight of up to 217 kg (478 lb) for later models.
• Tire Specifications: Precise pressure settings for the 21x7.00-10 front and 25x12.00-9 rear tires to ensure optimal trail stability.

Professional Maintenance & Identification

Never guess which part or setting you need. This manual provides exact locations for your vehicle's identification numbers to ensure compatibility:

• Frame Serial Number: Stamped on the arm hinge of the frame.
• Engine Serial Number: Stamped on the upper side of the right crankcase.
• Carburetor Identification: Marked on the left side of the carburetor body (Standard: QA04A).

Deep-Dive Technical Content

With 19 dedicated sections, this manual goes far beyond a basic owner's guide:

• Precision Engine Tuning: Detailed procedures for valve clearances (0.08 mm for both intake and exhaust) and idle speed calibration (1,400 ± 100 rpm).
• Torque Specifications: Comprehensive tables for every critical component, from cylinder head cap nuts (25–33 ft-lb) to the engine drain bolt (11–18 ft-lb).
• Fuel System Mastery: Complete teardown instructions for the dual-valve carburetor, including high-altitude adjustment settings (above 5,000 ft).
• Electrical Diagnostics: Full schematics for the CDI ignition, 200W alternator, and the neutral/reverse indicator systems.
• Systematic Troubleshooting: Expert charts to help you diagnose engine noise, low compression (Standard: 178 ± 14 psi), or transmission issues quickly.

Engineered for Practical Use

• Safety First: Includes vital warnings regarding carbon monoxide, battery hydrogen gas, and flammable fuel handling.
• Specialized Tooling: Lists all required Honda special tools and their equivalent commercial alternatives available in the U.S.A.
• Step-by-Step Guidance: Clear instructions for complex tasks like swing arm pivot bearing service, front hydraulic brake bleeding, and final drive oil changes.

Whether you are performing a routine oil change (2.1-liter capacity) or a complete top-end rebuild, this manual provides the technical depth and clarity required to keep your Honda TRX250 Fourtrax running like a legend.