System fault warning

[Gary B Townsend]

Was boating in my 26 foot Sea Ray last week on the Eastern Chesapeake, when I received a system fault warning that the Mercruiser 300 inboard/outboard was overheating. I turned off the engine and called a tow back to my dock. There, I was able to motor the boat onto the lift.

What might be the issue(s) that caused the system fault warning, and how might I check to find how serious the problem is?

 

[Boater420]

Welcome to CSR!

It could be any number of things:

1. Impeller in lower unit of out-drive needs to be replaced.
2. Water not making it's way to the engine. Bravoitis
3. Bad thermostat
4. Bad circulating pump on engine
5. Risers or manifolds need replacing
6. Water flow restriction in the system.

If you're a DIYer, you start at the lower unit and follow the path of the water. Do you know when the impeller in the lower unit was last changed? How about the risers and Manifolds?

When you run the engine on the hose, are you seeing a good flow of water leaving through the outdrive?

You'll have to try a few of these things to narrow it down. Let us know what you found.