Any Yamaha ATV Mechanics On Here?(07 Grizzly 660)

[Old Grizzly]

I just started having a sputtering problem with my grizzly about 3-4 month ago.When i take it through deep water the thing starts to sputterbut not all the time.Could this be a steam issue where the water hits the hot engine and creates steam and the intake suck in the steam and sputters.Please help its driving me nuts.The dealer cant find anything wrong but then again the dealer does not have a deeper water hole in the parking lot.Now when i say deep im only talking 2.5 feet not covering the 4 wheeler.Do you think a snorkel would help.
Thanks

[Mars]

I'm thinking you just have a bad spark plug cap or wire. Inspect the cap for hair line cracks.
Take a garden hose to the spark plug and wire while it's running and see what happens.

[Old Grizzly]

Cool ill try that tonight but the funny thing is that i have a rally 200 that does the same thing only it shuts down if you hit the water to fast any more ideas?