There was a time when building a dirt bike engine was not complicated at all. However, with time as things change, dirt bike engines have become a bit complicated. Today, you have to implement new techniques and install many different parts as standard since the engine types have changed as well. Therefore, in this blog, we look at rebuilding a dirt bike’s engine so that you are of the process should your bike need an overhaul. Before starting, make sure to buy all the necessary parts and tools from a dirt bike parts store. Let’s begin!
1. Install Piston Rings On Piston
After removing all the seals and other engine parts and inspecting the engine for wear and tear, it is time to install new piston rings and pistons. However, even before that, you need to check the ring end gap.
To do this, place the piston inside the cylinder so that it is square. Then, use a feeler gauge to measure and check the gap. Once you have achieved the correct ring size, you can install the ring pistons. You should check the ring for any markings or lettering before installing facing up.
2. Install Needle Bearing, Piston, Wrist Pin & Circlips
Before installing the piston, you should install one of the circlips on it. Furthermore, use your thumb to install the circlip. However, make sure that the circlip is not bent in any way and the ends are either facing up or down. Then, slide the needle bearing into the connecting rod’s small-bore. Proceed with installing the piston, making sure it is facing the right direction.
3. Install Base Gasket & Cylinder
It is now turn to install the basket gasket to the cleaned surface. Now that the gasket is in place, it is now time to slide the cylinder over the piston in order to reinstall. Using 2 stroke oil, make sure that you lube the sides of the cylinder inside, the rings and piston. Now that you need to drop the cylinder over the piston, using your free hands, compress the piston rings ensuring that the rings are lined up with the locating pins.
4. Install Head Gasket
Now that you are done lining up the rings with the locating pins, grab the head gasket and put it on the clean cylinder deck. Then, put the cylinder head on it, and torque the head bolts as specified in the service manual.
5. Install Power Valve Linkage
Make sure that you do not overlook the spacer when performing this step.
6. Install Other Engine Parts
Now that the major installation is done, continue with assembling other engine parts such as the exhaust, hoses, plastics, and mounts, etc. Lastly, fill the radiator with coolant and you have successfully performed the job.
Rebuilding a dirt bike engine can be a bit tricky at first but this article aimed to help you with that. As you can see, once you are aware of the basics, the rest comes easy. Just follow the steps above and build yourself an engine in a few hours.