i have a new 400 ex, if I remove the lid on the airbox will it boost anything, also if I remove the whole box and put a staulking over the filter will that doanything more, plus do I need to rejet it as people call it??

 

ny buddy tried no lid and it didn't help...so you will have to re-jet and maybe even add a pipe to run no lid

 

thanks squeege I was just curious as I've heard so much about it and if anyone else has any input that would also be great

 

I think removing the airbox lid and rejetting would make a noticable difference. I gained a few hp when I cut the lid off of my warrior, and the honda's airbox is even more restrictive becasue of the small size of the snorkel.