I have a client buying a 353 Formula. Twin 500EFI's with 50 hours on the whole package. The Headers on the port engine have a copper look to them. The company selling the boat says there is no history of overheating or a blown head gaskett. I have to pull the B.. card by the way things look. What are some visual trouble shooting techniques to finding if an engine has run too hot? This boat has Silent Thunder Exhuast. I will have a survey done and will see if both engines have serial ## that match the hull. Any information would be appreciated. I do not want my client to get burned on this deal. Thank you in advance.

Matthew W.DeLisio

I know this kinda seems far fetched.....but plugs will show overheating of course.........but the chances of them being the ones that were in there is pretty remote....... So another way is too smell the oil and see if it smells burnt?????

But here too...it could be fresh.......so another idea is to....look for a "new" impeller......that would be a sure sign of something fishy........at 50 hours I wouldn't think this would be "maintenence".......

I bet you thought I would do something smart......Huh????

The ECM module might keep track of this. One of the Merc techs should be able to tell you if it does.

I would do a compression test and a thermal scan of the engine while it's running. Check for blow by when warm, and look for excessive moisture in the crankcase vent system. Also check all the exhaust hoses for melting or distortion. One other note-if they are chromed headers they may have blued due to a leaking injector causing a rich mixture during operation.

Check the sequence of the sleeves and thermostat in the housing. We took mine apart to clean everything, and found the wrong thermostat in there, and they were in the wrong sequence according the Merc books. As soon as you see the diagram, you will know what I am talking about. You will need to remove the throttle body to check this out.

A Merc shop will have the Scantool for the ECM, that will record highest RPM, highest temp, time on the rev limiter and a host of other information.

If you don't have access to a Merc shop, I have a scantool you're welcome to borrow. It simply plugs into the unattached plug next to the ECM. However, mine has the older card in it, and your Merc Shop (assuming there is one near you) will have the latest cartridge which I believe gathers more data?

Steve

You mentioned the "copper look"...
It's a steel header, I'm sure, it should not have the copper look. Usually this is an indication of extreme heat, not quite the heat to turn it blue-ish, but it's a beginning. For whatever reason, that section of exhaust didn't get sufficient water for some time.

Thank you for all the help. I will print this up and hand it over during the mechanical survey. Now that I have my answers, I can go back to viewing OSO Porn!!! Thanks again.