Ok, real quick. I bought a DTX Raze last week. So far everything is stock (will get a few hop-ups next week) and runs great. But in a quest to get more performance, I'm looking to reduce some rotating mass from the drivetrain. Not only will it help with acceleration and braking, but also with overall weight reduction. The most powerful engine in the world doesn't do any good if you have a crappy power to weight ratio. So here's my question, the stock flywheel is 38mm in diameter. I have found a couple that are aluminum and should fit, but they are 1 or 2 mm smaller in diameter. What negative effect, if any, will the smaller diameter flywheel have on the engine?

I just noticed there is an engine section and I should've posted that there. Feel free to move thread mod.

uhmmm depending on how much lighter your flywheel is there may not be much of a difference, but if the difference in weight is a lot then you may experience your engine not idling right or not even being able to stay running, if to much weight is taken off..... Now with just 1 or 2 mm difference between the two I dont think you will have a problem with it......

The only thing that would be a problem is the reduced rotational mass of the drivetrain. The weight of the flywheel is a factor in getting the buggy moving. If you have a heavier flywheel it is easier to keep the buggy moving quickly and the engine doesn't have to work as hard to keep the buggy moving. A lighter flywheel will help the engine to hit higher revs more quickly, but will make it tougher on the engine to keep the buggy rolling and put a little more stress on the engine from the buggy itself. This is especially true after catching some air. When the buggy lands it will put immediate stress on the engine to get the buggy going again with a light flywheel, whereas if you have a heavier one, it will be easier to keep the buggy going after the landing and reduce shock and stress on the engine.