Last night I camped my equipment outdoors. Rain was forecast so I covered my Metro walkbehind with a tarp that had many small holes. Well it rained to the tune of 6". The mower started up fine at the first property, I made it up the driveway when it killed. It started back up again, and died. I do all the regular maintenance so I was miffed. The only thing that was different was that I left it outside...and the 6" of rain. I stopped at the Auto parts store and bought some starting fluid and HEET. With the starting fluid the engine came to life again. Only to die out when the fluid was stopped. I added HEET to the tank, which had approx 4 gallons of 87 octane remaining. Engine wouldn't run even with the HEET fuel system dryer. So I put to good use my High School drop-out education, I drank the gas...I mean drained the gas. Then I removed the carb from the 16 HP Briggs Vanguard and drained the fuel bowl, filled it with Isopropyl alcohol and drained it again. I reinstalled the carb, refilled the tank with new waterless 85 octane and the mower runs as good as new. It even has a higher rev? I dont know if the water was in the tank, or in the carb...or both? My question for you all. Is the isopropyl alcohol overkill for drying the carb? And, how often should a guy remove the carb and clean it? The bowl has a bolt on the bottom and a smaller screw into the side of it, what are these for? Any tips or suggestions are appreciated.