I have mine jetted with a 150 main, and a Twin Air filter kit. After I installed them my quad bogged real bad in 2nd gear until i took the air box cover off. Does anybody have any suggestions to prevent water from openly getting in the air box?

 

ehs lid but if ya take your llid off u should have a pro design clamp on unit in there its a super tight seal so u dont gat anything in there between the filter and the stock seal

 

I am running a K&N Powerlid and really like it, not only does it give you much more flow but block off the snorkle and it makes it so that only fresh clean air is getting into your engine. With the outerwear on the lid, it stops the little bit of water that would fall into the airbox.

For jetting I am running a DynoJet 160 main jet, needle clip in the 3rd groove with the DJ shim, and 3 turns out on the stock pilot. It pulls hard from the bottom but seems a little rich on top end, I could probably go down to the 155 MJ. This is for a Pro Circuit slip on exhaust, K&N powerlid, K&N filter and adaptor plate. Just note that the DynoJet main jets are numbers a little different then the mikuni jets, a 150 mikuni is close to a 160 Dynojet.