The Factory 4.1 system will give you a noticeable increase in all around power, and also shed some weight from your machine. Superior power on stock and big bore motors and the centralized mass improves handling.
FMF takes fun seriously, so they built the Mini Factory 4.1. This is an all out performance exhaust for play bikes. With the Mini Factory 4.1, you will be the king of backyard motocross and look great doing it!
Note: For closed course competition use only. Not intended for street use.