if you ever pay attention when you shut off your bike that the last thing it does it blows out a big blast of air then shuts off...and if it is running water cant get in becuase of the exhaust going out..i have never had a problem with one quitting while under water just pull it out and tip it backwards to drain the water out and remove the plug on the bottom side of the pipe and let drain...when you feel comfortable enough water has come out, start it back up after checking the oil just to be safe...