Ok, I ended up ditching the single carb set up for a dual carb. The carbs are from a rotax 580 in a 96 SeaDoo XP. I got the whole unit, cables and all. And the air box is frankly, much nicer than anything I could do. Only one problem, it hits the outlet for the cooling system. So after a minute, an idea, just flip the cooling flanges! Take the 90 degree thats on top, and move it to the side.
Works great! That plus I had to turn the scoop on the air box around to face the rear. I started digging through the pile of crap I have in the garage, and found a air box to an 89 Seadoo, low and behold, it make the perfect top for the 96. Plus a standard 3 inch K & N cone filter fits on the end of it!
In case anyone else thinks of doing this, here's a little info on the rotax cooling system. It does have an internal water pump, basiclly looks like a long screw. When the engines cold, the coolant enters the bottom flange, and bypasses the radiator out the top flange and back to the res. When the thermostat opens, it blocks that upper flange, and it goes out the top rear flange, into the radiator, then the res, then back to the engine. Supposed to help heat the motor up faster.
I of course was wondering if this was needed, and would I be hurting the engine if I just capped the bypass?? Is it going to burn up the pump since the water won't be able to flow until its "warm"