KFX 400 won't start.

Hello everyone. My husband and i have a kfx 400 which we lost the key to so we hot wired it. After riding at the river for a while and going through alittle water (nothing major) the 4-wheeler shut off and will not crank. It's getting gas and firing. The battery is fully charged, the wires are correct, and the fuse is good. When we do try to crank it, it will backfire but will never crank up. Any suggestions on what it could be????

[stickitracing]

Kinda sounds hydro locked pull the spark plug and turn it over.