Mercrusier 350 MPI Operating Temperature

[John Peterman]

Can anyone please tell me the operating temperature range for a sea water cooled Mercruiser 350 MPI engine. Bought the boat recently and was sure it was indicating 150-160 degrees F. on first use, but used the boat today and the temparature gauge did not even reach 140 degrees after 30 minutes use at 3000 RPM.
If anyone has the service manual for the engine, can you tell me if it has any specifications or references to optimum levels like temperature, before I invest in buying one.
Engine is in a 2004 Sea Ray 240 Sundancer. Love it!

 

[Dave S]

A sea water cooled motor will generally run around 160 or 165 degrees. If your engine is only reaching 140 degrees it could be the thermostat is stuck open.

Dave

 

[John Peterman]

Thanks Dave,

it did prove to be the thermostat stuck open. Getting fixed as we speak. Looking forward to getting back out there.
Sorry for the delay in reply. Was getting ready for trip to visit family in Los Angeles.
best regards
John

 

[Dave S]

Glad to help................have a great trip to Los Angeles. :thumbsup:

Dave