Tried Sinking My Boat

So I have an expansion plug in place of one of the frost caps on the engine. Simply to make winterizing a little easier. I'm hear to say that if you have something similar, it might be useful to pull them out and check them every once in a while to make sure they're good.

I put my boat in the water for the first time of the season and everything was running just awesome. A few miles down the river I decided to get on the throttle a little bit. Soon I smelled something burning. I opened up the dog house and sure enough there was practically a waterfall coming out of the hole where the plug was supposed to be. Water was starting to come through the floor by the time I got back to the trailer and the burning smell was the rubber on the exhaust starting to melt.

Everything is fine now, thank God. I eventually found that plug down in the hull and it was pretty well weathered, couldn't hold a seal anymore. Bought a new one from Autozone for $3, put it in, and ran it all afternoon.

Never heard of using an expansion plug on the engine block. Glad you made it back to your trailer!

Yeah the previous plug lasted the previous owner probably 10 years and it lasted me all season... who knows

For $3, I would carry a spare in a glove box just to be able to put it in right away.

Yeah, water doesn't come through the hole when the engine is off so I don't really have to worry about it. Just turn the boat off, run the bilge pump for a bit, find the plug and stick it back in. I know what you mean though, I should knock on wood now because the next time it happens the plug will probably end up somewhere where I can't reach it.

I'd put the OEM frost plugs back in -- pretty simple to replace, and then use the block drain plugs, from now on. They'll drain the water in about 30 seconds, and no more worries.

I wouldn't run a rubber freeze plug in anything, especially a marine engine with risk of sinking.

What OUI and cadunkle said. My $.02

Just some FYI, These plugs you are talking about, "frost plugs, freeze plugs" are not intended as so. They are acctually casting plugs, Only in the block to remove the sand from the casting proceedure. Do not rely on these to "pop out" when the block freezes. However this does happen sometimes when someone forgets to drain the block. The cast iron actually expands from the ice and the plug just falls out. I suggest installing the proper "brass" core plug and utilize the proper drain plugs on each side of the engine block for winterizing. Good luck Al

The boat sinking was just to get your guys' attention ; ) Water won't come through the hole when the engine is off.

I like the advice about putting the original caps back in though so I just don't have to worry about it. However, the reason the expansion plug was in in the first place was because the previous owner said he was having trouble getting all of the water to come out. When I winterized it last fall I pulled that plug out and extra water did come out. Maybe this is because the previous owner and I live in the same neighborhood and our driveways sit at similar angles? Maybe there's something weird going on with how we're parking the boat and how it allows water to drain?

Try harder next time. I'm sure you'll accomplish it. LOL :)



Seriously, though, I'm glad it didn't end catastrophic.

A little water left in the block is no problem. If you're worried about that. Flush some anti freeze throogh the system.