[toomanytoys2]

True, for optimal performance, you want a 4T muffler on a 4T engine and vice a versa. However, due to the fact that a 2T has a shorter power band then the 4T, the 2T will suffer more ill affect from the wrong muffler then a 4T will. Now, if I needed a muffler and I had a 2T one lying around, I would give it a shot. However, if I had to buy one from the start, I would buy the correct one 1st. Also noise is an issue as well. As master mentioned, the 2T and 4T motor have a different frequency exhaust output. While a 2T motor may sound obnoxious up close, the sound doesn’t carry very far. However, the 4T motor’s sound waves tend to carry a large distance and this is one of the reasons for the different construction. I have a left over muffler from my KX250F dirt bike that would probably make a pretty good muffler for a buggy. However, it would probably be on the loud side and doesn’t have a SA, so it is useless to me out here in CA. That is one of our biggest challenges when it comes to exhaust. We have to find the balance between what the law books say and the search for the best power for the least $