Hard clunk when trying to start

[pureinsanity]

The rain can do it, I have personally had it happen. I have a Merc 888 (302 Ford) and was getting the boat ready for the season, checked the oil and all was good. Started the motor on muffs and everything was fine. Shut her down and parked it off to the side at the house. We had a couple real hard rains the next few days. I'm talking you couldn't see anything 10 foot in front of you hard. Next time I tried to start the boat before we took it to the lake it just THUNCKED. Checked the oil...water, pulled the plugs...water. I got everything drained and good. pulled and checked the risers...ok. Then started it back up, run it for a while then shut down. Rechecked the engine after a bit and everything was good. I know for a fact my boat doesn't have the shutters in the Y pipe, they are gone and have been since I owned it. I know they should be in there but I just haven't pulled it back apart to install them. I have never had lake water push back up in the exhaust either I am probably just lucky on that account. I do though now store the boat with a cover over the prop and a plastic bag over the engine just to be safe that it won't get water in from rain again. And for the past couple years this has worked. My sun deck hinges right above the flame suppresser, this is the reason for the bag. I am a true believer that rain can do some weird stuff.