331 kit installed. power sort of weak at high rpm .dj jets .klx 300 header and muffler.air box off.do i need a O/S header?any one have one for sale ? dave.

 

I still say from lots of racing and jetting many kinds of bikes and atvs taking the airbox lid off hurts the power unless you change to a bigger carb and most important do larger valves and head work......your just trying to put to much air through a hole thats not big enough to take it...... I think the KDX Snorkle makes it run much better .....I tried it both ways with the stock bore and it pulled better with KDX snorkle and with a bigger bore at 331 makes it even worse.....if you want power the head is always where to get it but it costs big $$$$ so everyone never does it...Just a thought form someone that been there ......

 

klx300 owners report that the stock header is a major bottle neck. The muffler is good if you remove the butt plug in it. Give jerry a call at four strokes works and get one of his head pipes.

 

I found with my stock bike with the BG, I tried the cover off, and it definetly robbed the power. THe KDX snorkle on, ran much better and didn't sound bogged out as itdid with the cover off.

 

A performance header will give you such a minimum amount of extra power it will only be noticeable in your mind! Now putting on a high performance muffler, jetting mods, big bore kit, KDX snorkel and 13T sprocket - YES, major improvements! I ride with several others with KLX250's, one is set up like mine only difference is I'm running the stock header. Neither one of us can pull away from the other even after switching bikes - save your money and use it for gas!

 

do have 331 on bike.300klx pipe and open muffler.looking for some one who has a 331 and has used stock and a over size header.thanks. dave

 

Interested. How's your jetting. ? Sizes etc.

 

a DJ 132. NEEDLE 4TH FROM TOP.RUNS BETTR THEN BEFORE WITH STOCK 250 BORE.HEADER 250/300 KLX ARE THE SAME SIZE.MAYBE A o/s HEADER WOULD BE BETTER WITH THE 331?RUNS AS STRONG AS MY FREE MOD KLX 300 DID WITH 14/50 .MY 331 RUNS STOCK 14/42. DAVE

 

Give Jerry a call at www.fourstrokeworks.biz