Bigben - Tell your uncle to look at how his carburetor vent hoses are routed. I had a Warrior that was doing the same thing when I went through water. I cleaned all (and I mean every) electrical connections, packed them in dielectric grease, and siliconed the ends of the connections where the wires go in. Went riding and the quad would still cut out when I went through water. Ended up that a vent hose was routed up and over the air boot and pointed straight down. Well, steam coming off the engine would find it's way into that hose. It would then condense at the top of the hose where it bent over the boot. Then the water would run down into the carburetor making it cut out and sputter. I rerouted the vent tube into the airbox and had no more issues.