I have built a dynaflite super decathlon and I got a supertiger 2300. The motor runs great still breaking it in, but the muffler I got is a bisson inverted muffler. The problem I am haveing is I have to cut up the muffler so it fits. Bission makes a wraparound inverted should I invest in another muffler? I have already cut on this one.

If your cuts do not do any structural damage or weakening, and say you merely cut down the exhaust tube length, you should be fine.

Otherwise I'd replace the muffler.