i live in inkom idoh and got a400ex thats geting a new biggun set up and a k&n soon what sizes jets shud i use and is the biggun any good

 

i would start 3 or 4 sizes bigger, then get a new plug and check it to see if your running lean or not. as for the biggun pipe. i've heard that it only gives you low end but never ridin a 400ex w/ one on so i don't actucally know. i had a white brother e-series and was very impressed w/ the power