2006 400 auto goes into water up to food rests and stalls and will not restart until it is pulled out on dry land and away it goes like nothing happened until entering water once again. It seems once the bottom of engine hits with water it cools so quickly it causes some kind of vapour lock and stalls the engine.
No water getting even close to carb or electrical or exhaust, only takes about 10inchs water to cause stall.
This unit runs very hot has since new but has never gave me a problem in water until this year, very weird/

Anyone have a similar experience or a solution.
I have dealer talking to Arctic Cat Engineering but this will take a while.

 

I don't really have a clue but I can make a guess. Sounds like an ultra lean condition. Maybe you could try a 150 main jet.

 

I had the same problem with mine you might not believe this but it was steam being sucked into the air box I made a rubber shield to go over the air box and no more problem

 

Sounds to me like you have an electrical short somewhere and when you hit the water it is grounding out and you have no fire! Hope this helps!!!!

 

Solution found on water stall: after a great deal of investigation and diagnosis I found the problem with a water stall, the air intake top had a large gap matching to bottom so each time I would run hot and touch water to the bottom of engine it would steam up and get into the air box causing a stall.
Fix: Sealed up the top to bottom air box and cured the problem.
Also noticed specification for oil is 3.08L but in fact 3.8L of oil is better and helps engine run much cooler, also using 5-40w synthetic to reduce even more heat, still warmer than other ATV's but much better, this after dealer BS "It runs fine at the temp".