Ok here is my problem. My brother and I both ride Polaris Sportman 500s mines a 2007 EFI his is a 2010 Carbureted model. We are have a bad issue with water getting into the intake. We have recently gotten into creek riding which is a ton of fun but we get a lot of water in the intake. Mine handles it better than his I think because of the efi but his will just start sputtering and eventually want to quit running.
We drain the box every time we stop which is basically about every mile of riding. The water rarely ever is above the floorboards in fact I think the last time I went it was never above the floorboards but there is a lot of splashing and thrashing going on. Other quads are splashing us and so on.
Point is what is the best way of isolating the intake without the use of snorkels. I also use my bike for hunting and the snorkels get in the way.
My brother cut some foam and placed between the gas tank and the body which did help but he still eventually had problems. We have siliconed around where the intake meets the top of the airbox and the next step will be to make a new gasket for the top and and the airbox meet. We know water riding is going to call for more regular maintenance but everyone else who are almost exclusively riding hondas do not have these problems. Sure they take on some water every now and again but never in the amount we see in just a short stint through the creek.

 

I would bet it's coming it through the snorkle when you splash. I've got water in my clutch housing while blasing through water, never had a problem with the airbox. How much water are you getting in the box? I wonder if you could put some foam at the tip of the snorkle. If your gasket around the airbox is good, I can't see it entering there.

 

Usually its fills the drain tube at least every time we stop. Sometimes a little more. Eventually the filter gets soaked and the quads start losing power. I am pretty sure it is coming through the snorkel just trying to figure how to stop it. As far as I am aware we have not had any water in the clutch housing. I have tried to drain it while we were out but no water has ever came out and we have never really had any problems with belt slippage.

 

I would check to make sure everything is sealed properly first because I have had water to just below the seat and never had any problem with it getting in the air box. You may have a warped air box lid or something like that. I just can't figure that water not even to the floorboards could get to the top of the fuel tank and enough to soak the filter but not fill the clutch housing up when they both get air from the same area. Maybe I am missing something here but the clutch should have the same problem if it was just from the splash and spray.

 

That makes sense. I've had water on the belt, but very little, just enough to feel it slip, and it dried up from the heat, nothing to drain. Might want to spray some starting fluid around the box with the box sealed up, and see if it gets sucked into the box. As you can see from my avatar, I like going through water and have never had a problem.

 

i am going to make a new gasket and see how that goes. Never thought that the lid could be warped. I'll have to take a look at that.

 

Like reno82 said starting fluid is a easy check to see if you have a leak. Get it up to operating temp. first so everything that is going to expand from heat will do its thing and then check it. IMO anything that gets hot and then has cold water sprayed on it could possibly warp.