mercruiser 260 emitting steam

[tuantom]

5 gpm sounds like more cold water than the thermostat will pass at anything short of sustained wot - I doubt cooling capacity is your culprit in this.

Just out of curiosity, how do you define excessive steam?

I'd have agree with the suggestion that something's clogging up one side in either the manifold, thermostat housing, or hoses. I took my engine apart earlier this year - the flake scale was built up to the top of the freeze plugs. I could easily see this being problematic if it travelled to more confined passages.

[Marshall1]

With regards to the steam pic. see the attached. Photo does not do it justice as it is difficult to photograph steam without a dark background.

The Corsa Performance exhaust was on the boat when I purchased it. I can switch from "normal" to side exhaust. This has no effect on how much steam is generated. I checked with Corsa and they indicated it was the correct installation.

Frosty, what do you mean by "But youve got swop overs on it??"

[Frosty]

Marshall --sorry 'swop overs' I think we used to call them that is when you swop over the exhaust, from normal to side.

Regarding steam--I understand what you mean about photographing steam but taking that into consideration your steam photo looks perfectly notmal to me. What is the outside temp.

If the engine temp guage is reading normal I dont think you have a problem.

[bajaboy]

I know this is a way old thread but why is it an issue if its steaming while running? cold water entering a heated manifold usually emits steam no?