remove the air box, you need a 2" rubber coupler and a small piece of 2" pipe then reduce it to 1 1/2" then just take it up down under the cross bar then out the sideand up the side frame bar. Get a package of 5 or 10 pieces of sprinkler 1/4" splicers (black) dont get the brass to expensive and it makes no diff and a roll of the black 1/4 line all 3 of the lines that go over the cross member over the steering shaft vent them up ( if you want leave the radiator 1 down in case of an over heat it WILL splash you) I did the 2 (fan and differental and the radiator I left down but that is up to you) The K&n filter to a honda 400 at 05 fits perfect to the 1 1/2"pipe just put 2 SS screws 1 on each side to hold in place
you need another 2 2" rubber coupler but you will have to cut them a bit to fit good and another small piece of 2" then reduce it to 1 1/2" again, Remove the plastic half moon piece on the belt vent to install the parts. just route the pieces how ever you like out the side or like I did but the way I did them it is freekn hard and time consuming but it is worth in to me I am picky if you go that route you have to cut out a section in the bed just so u know. If you use the abs flex pvc use them under the cut out because if you paint them I dont know why they stay sticky. so I did it over with pvc and that holds paint well.
you need splicers of 3/8 i think it was plus line you need to vent the grey line out of the bottom of the carb and the gas tank and the line that goes into the frame tube on pass side
this was the end result for me with the textured flat blk paint
Filter on the vent not shown
I only lost 1 mph on the top speed but mine is stock and I dont do 40 mph in mud anyways.
I have yet to overheat or shutoff in water but I do take the radiator and the oil radiator apart to wash every ride I hate being the 1 slowing everyone down. Let me know how it goes