Need a littel help here guys. I have heard about gutting the stock muffler for freer flow and thus pwer gains. What is the procedure and is this worth doing? Has anyone tried this modification? Or another question would be has anyoen tried a universal aftermarket muffler, or for another bike like I think I have heard of guys trying the rancher exhaust?

Will someone please explain backpressure and how it appluis to power gains. I dotn understand this stuff very well. thanks in advance guys/

 

When i first got my arctic cat 250 i wanted a better exhaust and i spent so much time looking for a decent aftermaket exhaust. My search brought me to the kawasaki dealer down the street from my house. The guy at the counter asked what i wanted and i said i wanted my bike to be noticed, i wanted it loud and to get better perfomance. He looked for me and found no high performance exhaust for my machine but what he did find was a 2 stroke silencer that dg makes for the suzuki quadracer 500, all i had to do was make my own brakets in auto shop and it worked great. The silencer is so loud it rattles the windows in my house and gave the ol'250 alot of pep.

Do yourself a favor, don't try messing with your stock muffler, just spend the 100 bucks for a silencer that can be made to fit your quad.

 

Now for your next question...backpressure. in a perfect world you don't want any backpressure so the fuel air mixture entering the engine has as little restriction as possible, with more backpressure thoughyou don't need as much gas in the air fuel mixture so your engine runs more efficient using less gas. However with too much back pressure you will melt your exhaust valves because excessive backpressure causes your exhaust valves to superheat.
Back to lowering your backpressure. Doing this is a great way to increase the power on your machine...however with big bore machines 300cc and higher its necesary to jet your carb so you have enough fuel to compensate for the unburned gas you'd typically get with the stock backpressure.
When i first put my muffler on it ran fine, the fuel demands for a 250cc engine isn't too crazy, it ran it all summer without a problem. This fall i jetted it just to give it an extra kick. that on top of the k&n makes my 250 get more power than most 300's.

i hope that helps out a little, i've taken college courses on engines so i know a little about what i'm talkin about.

 

thanks mudcat now backpressure is "clear as mud". I will be looking for a muffler to fit my 300. What pipe did you go with?

 

super trapp make a universal exaust its LOUD it can be heard over 3 ATVS