How to Do a Top-End Rebuild on a Dirt Bike

Dirt bike riders are really hard on their equipment, jumping and dropping the bike and pushing it to its limits every time they take it out. To keep a dirt bike in top running condition and to avoid bigger problems, a top-end rebuild should be done at least once a year, whether you are having any technical problems or not. Some riders do the job every 200 miles or so.

Instructions

Difficulty: Easy

Things You’ll Need:

• Torque wrench
• Base nut adapter
• Rubber mallet
• Razor blades
• Solvent

1. Get out the manual. Unless you are a professional who looks at dirt bike engines all day long, you should have the manual handy before you start taking apart your engine.
2. Drain all the fluids from the bike and remove any parts that are in the way of reaching the motor. Remove the spark plugs and the carburetor.
3. Pull off the cam cover and the cams and chains using the right-size tool for your engine parts. Make sure all the timing marks are lined up.
4. Clean and check all the valves and sprockets to make sure everything is fitting properly. Use solvent and a mild abrasive such as steel wool or razor blades to scrub any build-up.
5. Remove the pistons and rings. Line up all the parts in the order they were removed. Replace worn parts.
6. Put everything back together and tighten all the bolts. Add oil and take her for a spin.

Tips & Warnings

• Don't force any piece off, work it steadily until it comes off.
• Be careful when easing off the cylinder over the pistons rings so you don't snag anything.
• Don't disconnect all the clutch cables, but loosen them so that you can keep them out of your way.