Jetting help

[TRX400EX02]

I am going to purchase a White Bros. E-Series pipe for my 400ex and I was wondering if I will need to rejet, and if I do what do I need to buy? I have a K&N airfilter with the airbox lid on if that matters.

[TRX400EX02]

Oh yeah....I mostly ride at 600-800f ft above sea level.

[Pappy]

pick up a 152 and a 155 main jet

install the pipe and the 155. if she feels a bit sluggish on top go down to the 152.

[TRX400EX02]

Thanks I will try that.