How to Rebuild a Top End on a 4-Stroke Dirt Bike

Back in the day, rebuilding your two-stroke top end was a simple thing to do. Slap a new piston kit in you were ready to go. You didn't have to worry about camshafts, timing chains, or valves. But today, with the vast popularity increase of 4-strokes, there are a whole new host of moving parts you have to get familiar with when rebuilding your top end. Don't fret! Changing the top-end on your four-stroke dirt bike is easier than you think, especially with the help of our How-To Guides below.

In these guides, we'll refer to the top end of your four-stroke as the piston, cylinder, and head - as well as the components the head houses.

Steps to Rebuild your 4-Stroke Top End:

We’ve come up with separate articles that you can use as a guide when you plan on rebuilding your four-stroke top end.

Read about how to replace your dirt bike piston
Read about how to rebuild your dirt bike head

Pro-X do a great range of Piston Kits, Valves and Gaskets.

Replacing and Installing the Valves in your 4-Stroke

If your engine has been running for quite a long time already, it might be time to have your valves, valve springs, and all the other valve components replaced after you inspect the head. We wrote a guide on how you can install your new valves in a four-stroke.

Doing these maintenance checks all by yourself can help you save a lot of money in labour, although you still have to make sure that you use quality parts. You can find a great range of affordable parts with the best quality at Firestorm Motorcycles.

● Read about how to correctly install the valves in your 4-stroke

If after you’ve rebuilt your four-stroke top end and problems still persist, you will need to look at other causes. It could be anything from the clutch, to the cooling system, and perhaps the bottom end components. If you can’t find the culprit, we’ve listed 12 possible signs your engine might be tired:

● Read more about the 12 signs your four-stroke needs a rebuilding

** Source:
“How To Rebuild a 4-Stroke Top End in your Dirt Bike or ATV”, Pro-X Blog