'06 WR450 header pipe diameter

[bkridin]

Bought this bike a few years ago and decided to put an FMF slipon exhaust because the stock pipe is loud. I suspect someone has tampered with the internals because I don't think the stock pipe should be this loud. Anyways, the slip on inside diameter is nearly identical to the od of the header pipe. Is there a chance that someone has put a YZ exhaust on my bike? Not sure if the header pipe is slightly larger on a YZ versus a WR. I have purchased an enlarging tool to open the id of the slip on but it may be just as easy to find a stock WR header pipe and swap it out. Anyone have the OD dimension of the stock WR pipe on an 2006?

Any help would be greatly appreciated.

Bob

[flynz]

Yes the WR headers are smaller YZ header will fit or buy a Power Bomb of Mega Bomb.