All installed, off road riding for a couple of days, very noticeable difference. Does not bog down on a steep dirt hills now, just twist and go.
I need recommendations on a pipe and jetting with the stock carb. Pumper carb sometime in the future.

Mick

 

bill told my mechanic what to do jetting wise and i love it with the stock pipe

 

You really should use a complete system ( header and silencer) - The Barker system offered thru Bill, the complete Four Stroke Works system (their KLX300 header and silencer), complete FMF system ( using the Powerbomb or Megabomb ), the complete Big Gun system, etc etc.. Read the sticky on performance exhaust choices...

If you are sensitive about noise, only the FMF system, using the Quiet Core 4 silencer, is known to be relatively quiet..

If you also want to open up the induction side - by running the airbox lidless - I have lidless 351 CVK setups that are "known working" based off the lidless 250 setups..