Could it be that the stock system has a gasket between the muffler and head pipe. Looking at Tom's bike today it looked like there was some sort of asbestos[sp] like gasket. Sock muffler looked like the female part?. I will look at my stocker tomorrow.

 

I don't see any kind of gasket on the stock header. It does have what appears to be a sleeve/flange mechanism welded to the header pipe, which receives the receives the muffler pipe. Then the clamp is tightened around that.

Ok, I've not worked with metal so I had no idea it would be an easy job for a muffler shop to simply expand the diameter of the header pipe. There happens to be such a shop within walking distance of my house. This is a good thing because I bought the muffler online and the merchant has not returned my emails.

Thank you for the much needed help and discussion.

 

My stock head pipe. Gasket OD=37MM, ID is 31MM. My bike is a 09, part# on FMF box 042173.





Yours may vary.

 

Yep, my stock headpipe looks much the same, minus the silver gasket material. I don't have that. However, what I do have is the answer to close this entire thread. Wish I would have done this earlier and I wouldn't have had to waste everybody's time by starting this thread.

I loosely installed the header on the bike again, and wanted to get and idea of how much of the header's diameter would need to be expanded. Well, I got a much more specific answer. This pipe doesn't even line up to any of the brackets that receive the muffler bolts. Not to mention, the midpipe doesn't even reach the Powerbomb header when it's in place. The entire muffler is a misfit.

I have a bad feeling I'm gonna take it in the shorts on this one. Sadly, I can't even identify what Model this FMF Powercore 4 muffler is in order to try and re-coup my cost by selling myself.

I'll cross my fingers the merchant will soon respond to my emails but I'm not holding my breath.

Thanks to all who helped.

 

Sorry my fix didn't help you...try selling what you have on CL and get some $ back...GL

 

Thanks deuce. I would try selling it, however, this muffler is marked #042000(for KLX250/300's) yet it clearly will not fit a KLX250/300. I have no idea what it will fit so I can't really advertise it accurately. I certainly don't want anyone else experiencing a raw deal like i did.

Thanks again to all.

 

Sounds like a 250 header and a 300 muffler. 300 has a longer header.

 

Ok, I have some updates for this post which I think are of value. I decided to take my chance with FMF customer service and discuss what's going on. I was slightly dreading it after reading all the unhappy things said about their customer service. However, those fears quickly evaporated.

I spoke with Mike Moyer, and let me tell you, his customer service and attention to detail was so outstanding, he re-defined the standard. After asking a few questions and requesting some pictures by email, he was back on the phone with me, explained the steps I needed to take, and FMF would do the rest to get me the appropriate pipe.

If I were gonna change anything, it would have been AWESOME if they'd have paid the shipping back to FMF since technically, they packed the wrong pipe in the box. However, I'm not one to complain, but damn pleased my dilemma will soon be corrected.

Thanks to all.

Note: Soon, I'll most likely have a stock, full exhaust off of 2007 KLX300R on my shelf until someone takes interest in it.