do a quick check of you airbox look closely at the rubber seal. make sure the lid fits the box!!! i have seen several new units that the lid is not sealed. the box is sticking out past the lid on some of these. what this does is let water into air box.

 

My lid is very very hard to remove. Don't have the machine in front of me, but that may explain why mine is sticking (it is being forced onto the slightly larger box???).

 

no its not sticking but when examining the box the lid does not fit well onto the box... have you been getting water in the box?

 

The air box cover on my quad looks fine.