Why melting your exhaust flappers is not good.

[DanoC33]

A few weeks ago, I managed to overheat my boat and in the process, I managed to melt the exhaust flappers / water shutters. All that was left of the flappers were the small pins that the flappers hinge off of.

After asking around, I was given a lot of advice ranging from "the pieces will just blow out the exhaust" to "pull the motor" as well as "remove the outdive and check for missing parts". After weighing my options, I decided to remove the outdrive and check for any missing pieces. Well, I just got around to doing that today and along with a few pieces of burnt up rubber, here is what else I found.

In case you are wondering, those are the metal pieces that each flapper is made up of, and there is no chance that they would have been blown out the exhaust. At this point the boat is almost ready to be put back into the water, and with any luck, I hope to never have to deal with an overheat situation again.

D-

 

[beachcombersc]

Glad you were able to get them both. What caused the overheat???

 

[DanoC33]

Kind of hard to tell from the pic but there are actually 4 metal pieces in there from both of the melted flappers.

The boat overheated when the rear freeze plug fell off. As soon as it fell off, the motor sounded like the exhaust was inside of the boat. I immediately throttled back and shut down but it was too late as my motor proceeded to bake and smoke like crazy.

The freeze plug has since been replaced and all of the exhaust tubing, the gaskets, and the flappers have been replaced. The moral of the story is don't overheat your motor because I can assure you it is not cheap to fix!