So as the title says, I was cleaning my bike yesterday and noticed the two bros stamp and some numbers on my pipe leading to the engine, the stamp and numbers were real close to where the pipe disappears under the fairings. So I'm assuming that it's not just a slip on? and if so im guessing I'm running rich or something and need a mapped out PC. I looked on the two bros website but for f4i's it only has one slip on option for 01-07(I know they stopped in 06 so idk why 07 is there) and nothing else, and that slip on doesn't look like my pipe. At work posting on my phone so I can't put a picture up at the moment, but any help is appreciated!

 

I don't think two brothers ever made a full system for the f4i, you are probably looking at their mid-pipe. The exhaust goes from muffler/slip-on to mid-pipe to the header/exhaust manifold. The mid-pipe is just a pipe that goes from the slip-on to the header.

 

Your right that sounds like it, thanks for clarification! So it doesn't effect the bike at all?

 

A full system included headers. That's what makes it a full system. A slip on is a canister and a mid-pipe which bolts to the headers. Some bikes don't really have a long mid-pipe. No it will not affect the bike at all.

 

Mkay cool, appreciate the info