Hey i have a hsp pipe and K&N filter. I moved the needle jet "E" clip up one and ran it...it was lean so i put it back to stock and it seemed like it would sputter in the 1/2 throttle range...so i put it down one and it still sputters... Think it is the main jet??? cuz i only thought the main jet was 3/4 to WOT... i did a plug test for the needle and the plug was tan(which im pretty sure means right on the money almost) So i have no clue why its doing this. someone please help...thanks

 

If you pull off the air box lid, does it get better or worse? Im thinking its lean, and pulling the lid will make it worse. this article has some good tips on figureing out the jetting.jetting