Build your air box out of thin plexiglass. The design is limited to the space you have to work with. Make the box as and intake tube as big as possible. You need to get the two carb boots for the 800 carbs, then start from there. If the box can be fairly square. . .this is the easiest as you can fold and bend the plexiglass to make the majority of the corners seamless. the ones that you can't, use pop rivets and good high temp silicone to seal them up. The plexiglass is forgiving and easy to work with. . .cheap to. In the end you will end up with a airbox that looks pretty stupid, but, will be highly functional. Since the airbox will be clear. .. you could add some neon lighting for some bling if you like. . .
For the filter part. . .the best thing that I have found is panti hose. It stays flexible and if snow starts to plug it, its quick and easy to clear. The trick is to get enough surface area to get your air flow. If your intake tube into your airbox is say. . .3 or 4 inch tube. . .you wouldn't want to just stretch panty hose over the end of the tube. . .that would restrict the airflow to much. Somehow. . .you need to figure out a intake filter box. . .something that gives your filter allot more surface area. This does two things. . .the main one is that it slows down the airflow, thus pulling in less snow. . .allowing to to move on by. It helps if your air intake is behind or under something to keep snow from directly piling on top of it. . .but allow outside air in. The other thing it does is give your filter material more area to plug up, which means more time before you feel the lack of performance. . .and have to take the time to clean. Building an airbox that actually works is much easier said than done. In order to make mine work. . .I had to put a crook in my stirring rod first. . .to get it away from the mag side carb. . .good luck.
