Waterproofing airbox

[PunkA$$]

Ok, so I cut a hole in the airbox lid of my 400ex and used some 1/2" or so stainless steel strapping and a crud load of rivets to hold a hacked up old prefilter from my K&N on top. It went together real nice and looks great, thing is that old prefilter does'nt keep out water for crap. Any suggestions on a different material I could use or maybe something I could spray on my prefilter to make it waterproof?? I was thinking maybe scotchguard? Thanks!

[Rootar]

i dont know anything but when i had my 250 we added a k&n filter i took the stock snorkel off and made a custom one out of plumbing hose and made smooth curves for the air to flow better and i put it right at the top behind the light and i could tell it was gettin more air cause we went up one jet size

[PunkA$$]

Good Idea!

[400-416EX]

Not sure about the water. I run a uni with the lid off for mx and if the track is real wet, I get water in my air box also

[BassGin3]

There's a store around my way called Lids that sells only hats, and they have this waterproof aerosol spray for hats that still allows it to breathe but yet the water beads off the hat. If there's a Lids around you, it might be worth grabbing a can for a few bucks and trying it out.

[PunkA$$]

I was able to find a silicone spray, a sealer water repent type thing and a can of scotchguard today, I'll try them all tonite on samples and let you know what works best.

[400-416EX]

Cool good luck

[PunkA$$]

Holy crud.....I tried a bunch of different products but what worked the best was tent sealer or tent waterproofing mist. Barely lets a drop of water through but still breathes good. The only thing I could'nt test is how long it'll last. Think I'll spray my airbox lid and get another prefilter and spray that too.

[2001-400ex'er]

I was thinking, wouldnt just drilling holes in the air box work? then when you go into mud just put some duct tape over them if its dusty or wet out?

[PunkA$$]

Ya, that would work but you'd still have to rejet every time you took the tape off or put it back on. Too much dang work if you ask me. Personally I'd rather leave it one way or the other. This tent sealer works great, I held it under the faucet and the water just rolls off.