Story from my boss - Honda VTR250 was totally submerged in a flood, up and over the tank. Bike was found bobbing around in the water of a flooded underground park. New battery, plug out to spin it over, blew out the exhaust with compressed air, and then it started. Same oil and fuel, before a service anyway. Shows that Honda put thought into properly sealing stuff like air box, crank breather, fuel tank etc.