[96MariahZ220]

First off I have a 96' Z220 with 5.7 mercruiser.... What is the normal running temp of the engine when it's "warmed up"? My temp gauge seems to not move up much. Just over 100... Do these have sensors that go bad? Ran it for several hours yesterday and it sounded great/ ran great. Any input is much appreciated. Thanks!

[finleydj]

Mine is the same setup. I run about 180 degrees give or about 10.

[96MariahZ220]

Originally Posted by finleydj

Mine is the same setup. I run about 180 degrees give or about 10.

Okay, that sounds about right, my temp reads way lower.

[Andy b]

Could be running without a thermostat.

[96MariahZ220]

Originally Posted by Andy b

Could be running without a thermostat.

Well you are exactly right. Pulled the thermostat housing off, not one there... Now I am concerned as to why there was not one in there... I went ahead and ordered a new one I'll put it in and hook it up to the muffs and she what happens.

[Andy b]

It's good practice to pull the stat out when winterising. It may have just been overlooked in the spring rush to get on the water.

[96MariahZ220]

Okay, so I replaced my thermostat today with a 160 degree thermostat, surprisingly very easy to do. I let the boat run on the muffs it took a long time to warm up and finally settled in at the "1" on the 175 degree mark so just below 175 is where it idled at, maybe 165-170? I rev'd the RPMs up a little and it started to cool back down a little bit. Ran it for maybe a half hour or so... Does this sound about normal? Thanks