I have been thinking about buying a big gun exhaust system for my 650 prarie, my question is if i run this pipe, will it be nessessary to re-jet the carbs, i will be getting the entire pipe not just the silencer, i was also thinking about k&n filter and uni-vents...i live in pennsylvania, in the appalacians,
what does everyone think?

i do want to say that this site is very informative, ive been reading the posts for several weeks now but this is the first time i posted. nyroc, your site is awesome, i cannot believe some of the things you put your 650 through, unreal....

 

There have been several previous dicussions RE: Mufflers/pipe. I haven't started a serious search yet. I DO KNOW that that the HMF muffler DOES NOT have a U.S. Forestry Service approved spark arrester. I have to run one, as I operate in several Federal Forests and State Forests. I am told that there is a VERY large fine for not use one in the required areas. Something to consider!

 

My HMF does indeed have a approved spark arresror, must order it seperate with the quiet baffle, as far as jetting with the pipe. yes I would, because they are jetted lean already and it's better to be safe than sorry, also you won't be getting the maximun benefit from the exhaust if you don't rejet.

 

I have a Big Gun on my 650, havn't re-jetted, but I live 100 ft. below sea level. More than likely that makes a difference. Non-the-less, I can feel an immediate difference in the performance of the bike with the pipe on. I have never used the spark arrestor, but it did come with one. Just never hit the national forest. I have 2000 acres only 3 minutes from my house, that I can ride on, so not a whole lot of need to go elsewere.

 

Stakk-- You may want to look again, at your muffler. Two weeks ago I called the HMF factory in Cleveland OH. and was told specificly that the HMF muffler for the Kaw. KVF650 A-1 WAS NOT equipped with a "U.S. Forestry Service Appproved " spark arrester. Is the above quote stamped in to your muffler housing? If so, those people at the factory customer service dept. are not very bright!?! You may have an arrester.....but is it an approved one?

 

As far as I know, and saw when I recieved mine. The arrester is not built into the pipe itself, so the service techs would be right in saying it doesn't come with one. But rather it is a seperate piece that can be removed when not in a restricted forest area.

 

Well....I guess that I will call HMF again to see what answer I get THIS time! I would have bought their muffler IF I was assured that it was U.S. Forestry Service approved! I was told (2 weeks ago) that it WAS NOT!!!???!!!!

 

OK... The HMF spark arrester is NOT APPROVED by the U.S. Forestry Service. It is stated on HMF's website. Click on "spark arrester". Go to: www.hmfengineering.com

 

The one I have is the screen type that is built into the quiet core baffle,just like the Pro-circuit, the fine mesh screen that looks like a cone, showed it to the wildlife agent and he said Yep, you're good to go.