I run mine completely submerged with my snorkle and i have my pull start sealed all the way around the housing and in the drain hole and the top where the cord comes out of the top and also I have all my vent lines run to the snorkle other than the one coming from the carb bowl and i have never had a problem other than forgetting to plug the carb bowl hose before i go deep and then the only problem is I get water in my fuel and have to drain it and run the engine for a minute to get all the water out and i have pumped water out of my exaust at least ten times and have never had a single issue yet and my foreman is 1 1/2 years old. I spend 90% of my time in water.