I have a friend with an 06 KX250F. He is not using his OEM muffler. If I am able to get the muffler to mount up to the header (I work in a company with a full metal shop), do you think that my 09 KLX250S would run any better? I have done all the free mods. I am jetted at 130/38. If so, would it run better at the top end or bottom? Anyone out there tried this already?

 

All the muffler does is keep the noise down. If it's more free flowing than the OE you'll gain some performance. You can fit it if you like, It will look better and weigh a lot less. Post some pics of the finished job.

 

I thought that was the case. I will also lose the cat converter that is in the OEM muffler on my bike. If I decide to do this project, I will post the pics.

 

If your use to doing metal work it shouldn't be that big of a deal. Good luck.
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PISSING TUBE