Thank you to all who have helped me get my 2006 klx 250 breathing. Airbox, Filter, screen ectomy, carb jets n mods are done and she runs pretty well. It was about 50 degrees last night and she fired up in 2 cranks with no choke.

The last phase is tweaking the exhaust. I recieved my klx 350 header yesterday. The flange had very abrupt squared edges and there was a fairly tight restriction where the flange was welded to the pipe. The inlet hole was also not very round.

I used a cone grinding wheel to bevel the flange, remove some constriction and round the inlet. I "think" it should make the pipe flow better.



The KLX 300 muffler isn't here yet but when it arrives I want to be ready to wrench.

Any recomendations on "preparring" the KLX 300 can for maximum KLX 250 flow and still keeping the DB level low?

 

There is absolutely nothing that needs to be done to the 300 exhaust other than removing the "but plug" if it already hasn't been removed. Two bolts. An aftermarket tun down tip, which replaces the "but plug" and utilizes the same two bolts, will keep the soot off the fender and make it slightly quieter.

 

Where did you buy the KLX300 Header and Stock Can?
How much was it?
Thanks, Chris

 

Stock KLX250/300 off road exhausts are on e-bay all the time. I have seen them sell for as little as $9.00 up to $75.00. I think the 250S market has driven the price up a little. The header provides no performance gain. It is longer so the 250/300 exhaust will fit. For performance, the biggest bang for the $ is a Four Stroke Works Header, about $150.00, with a stock 250/300 off road exhaust.

 

Cool. Thanks. I'll be on the lookout for one.
I want to see the difference in dB and Power versus the Big Gun.