Honda Fourtrax 90 ATV Repair Manual 1993-2000

This chapter provides information for the removal, inspection and replacement of the major assemblies that make up the engine top end.

This includes the cylinder head, camshaft, valve, cylinder and piston. The parts can be removed with the engine mounted in the frame.

This chapter shows the engine removed for clarity. Refer to the tables at the end of this chapter for specifications.

Read this chapter before attempting any repair to the engine top end. Become familiar with the procedures, photos and illustrations to understand the skill and equipment required.

Refer to Chapter One for tool usage and techniques. When special tools are required or recommended, the part number is provided. The special tools can be ordered from a Honda dealership.

Procedures, photos and illustrations are representative of the model years covered in this manual. When necessary, information that is specific to a model year(s) is provided.

Separate the engine crankcase to remove the transmission (Figure 1) and shift drum (Figure 2). Remove and install the transmission assembly as described in Chapter Five, Crankcase Disassembly and Assembly.

Once the transmission is removed from the crankcase, disassembly, inspection and assembly can be performed. Carefully measure the parts and keep them oriented. The gears, washers and circlips must be installed in the same direction.

Since some of these parts are identical on both faces, remove and store the parts on each shaft in the order they are disassembled and in their direction prior to disassembly.

Use a piece of wire threaded through the parts or an identification mark on each part.

Always install new circlips. The circlips will fatigue and distort when they are removed. Do not reuse them, even if they appear to be in good condition.

• General Information
• Troubleshooting
• Lubrication, Maintenance and Tune-up
• Engine
• Clutch and External Gearshift Linkage
• Transmission and Internal Shift Mechanism
• Fuel and Emission Systems
• Exhaust System
• Electrical System
• Wheels, Tires and Drive Chain
• Front Suspension and Steering
• Rear Suspension
• Brakes
• Body and Frame
• Wiring Diagram