General Articles

DIY Go-Kart Engine Rebuild

One of the very first things you should do when rebuilding your engine yourself is to get a service manual for the motor you will be working on. Make sure that you consult the manual for various recommendations pertaining to the specifications of the engine and engine tuning. Follow the steps below as a reference for the best way to rebuild a go-kart engine and any other small motor vehicles.


Getting Started

After emptying the oil and taking it out of gear, it needs to be cleaned. Dirt is the biggest enemy of small engines. When the exterior of the motor is washed, proceed to wash worst areas that have oil and sludge residue and be sure to utilize your service guide to disassemble the motor properly. I take pictures along the way as a reference when resembling the motor. Small parts can be hard to identify hours after you have taken them apart. If you get stuck and can’t figure out how to rebuild the motor you can always reach out to a Redmond mechanic for advice and possibly help with rebuilding the engine.

Taking Apart The Engine

Since you’re taking the motor apart, inspect every part for indications of wear. Make notes and/or speak into your camera regarding the issues and possible parts that will need to be replaced. Important things to search for are signs of discoloration (brought on by heat and oil), aluminum which has melted and adhered into other elements, scratches and scuffing. Ideally it would be nice to identify what’s been happening within the engine to prevent the engine from breaking down again. If you don’t resolve the issue that caused the initial breakdown it’s possible that the engine breaks down again. So make an effort to identify where the problem exists so you can prevent it from happening again. If at any point along the way you can identify that the cost of the rebuild will equal 50% of the cost of a new engine then it might just be time to buy a new one.

Inspecting Parts

Now that the motor is apart it’s time to take a few measurements. Consult your owner’s manual for specific dimensions pertaining to the engine. Taking precise measurements of the cylinder bore is essential to ordering the right part. While the motor has been working the piston stones from side to side as it moves up and down the bore. This induces that the bore to become egg shaped. In addition, the bottom of the bore wears over the top. New O Rings won’t seal at a out-of-round cylinder. Cylinders can be revived by dull to Oversize. Oversize is generally .010″, .020″ or .030″ bigger than the conventional bore that is recorded in your guide. You are going to want to utilize the tiniest OS that will fix the cylinder so the motor may be rebuilt more than once. The crankshaft may also have to be reconditioned. If you don’t have the resources to take these dimensions, take the components to the local machine store or mechanic and have them repaired. The machine shop will then inform you exactly what “oversize” piston and ring collection you’ll need. They’ll also inform you what Undersized linking rod is going to be demanded if the crank was turned down to fix wear.

Ordering Parts

It’s time to purchase the components which you want. Some motors have rebuild kits out there. With others, you’ll have to order different pieces. The components you’ll surely want are gaskets. While you’re at it, then rebuild the carb with a Kit. And by all means replace the Oil Filters, Air Filters, and Spark Plugs.


Do not forget the proper oil. Run the motor for approximately 5 minutes in almost full throttle and let it cool a few. Change the oil to eliminate the very first break-in cycles metal residue. Some engines require the head bolts be re-torqued following the motor melts entirely. Again check your guide for those manufacturers recommendations. After the initial 10 hours or significantly change the oil.

Assess the oil often in a fresh engine. New engines and rebuilt engines can and can use more oil throughout their break-in period. Good luck to all of you!