Get an ehs powerlid. Its a outerwares cover over the airbox lid. I ride in alot of mud also just not deep water. Which you shouldnt be in anyway.
While I'm riding my blue 300fwd my riding buddy is on a 400ex that he bought recently
His lid was missing when he got it so got another one for him
BUT..... Watcha mean shouldn't be in deep water.
That idiot frequently Parks in deep water, not to mention plowing through or across every mud hole he sees!!
Seems if ya get enough speed momentum will either carry ya across or plant ya in a rut wondering how you landed so far from the bike. ?
Did I mention he's a Idiot. ?
Just removing the air box lid alone won't really add much to your noticeable power but it will make it a Lot easier to flood out
Adding a HP exhaust system and then more air is the quickest and easiest way to create more noticeable"power" in pretty much anythingg