Yea you're probably right, I called it the "under" muffler... Did the '07 have a converter? :idk: What I do know is that there is an insert that can be removed in many Yosh models. We did my buddy's GSXR600 last year and I almost begged him to put the silencer back in! OMG fucking loud! Like you said, we removed the muffler/exhaust tip and the "under-muffler" on muffler/converter combo. Anyway, before anyone breaks out a fucking drill, they should first determine what model slip-on they have (wasn't mentioned in OP) and give Yoshimura a call!

The Yoshi I had on my last bike ('06 R6s) had that, it was wasy to pull out and that's the sound/volume I am looking for. :wink:

Don't worry, I won't do anything without checking with Yoshimura or have a mechanic do it for me. :D

The 08 and 09 GSXR600/750s had the cat welded to the header. You could pull the stock can and put on any aftermarket slip on and it doesn't change sound or performance. You might have the same thing going on. If your cat is not welded on pull it off and have a pipe custom fitted to go between the slip on and the header.

or punch out that cat. Gonna need a pcIII after you do it though

All '06+ new bodies have a cat.

I just yanked my silencer out last night. It was a beeyotch.

Well, was it technically held in with an allen head screw?:lol: Seriously, one thing I've found with the inserts is if you leave them in for a while they are MURDER to get out and if you leave them out for a while, you can forget ever getting it back in!:lol:

Took the silencer out of the Yosh when I installed it on the SV... Thought it was a bit loud at first, but got used to it.

Now... compared to the Buell, it sounds stock :lol:

Well, did you have to drill or did it come out with a screw?:lol:

2 allen screws.

I could put it back in, but then it would be REALLY quiet.