Airbox lid off question

I was going to take of my airbox lid and I was wondering how far and what I would have to jet up on, like my main jet, needle, etc.

[redrider ex]

do you or do you still have the stock one on there if its still got the stock pipe on there then it won't do much good but if you have on a after market pipe it will make a big difference but don't ride in the water because it will get in there real easy i now a guy that just raced in a cross country race and he had his lid off and hid a creek crossing and filled up the air box and it sucked in a lot of water and it compressed it and it bent the rod on his brand new 400ex