Temp Range For 1976' 888 Mercruiser

Joined
Apr 21, 2002
Messages
15
I have a 1976 888 Mercruiser on a 21' 4000lb Larson. 17" Pitch prop, 140 deg thermostat. 2bbl rochester, Fresh Water Cooling and cabin heater. At idle (800rpm) temp is at 140 or returns to 140 when slowed(800 rpm). At 3000 RPM (23 mph) temp creeps up to just under 180 deg. Good temp gauge, sender, new water pump, exhaust manifolds and mallory distributor last year (end of season). water passages in engine and cooling system clear. Engine runs and starts great. Is 180 deg normal or OK?
 

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Fleet Admiral
Joined
Mar 25, 2001
Messages
8,217
Re: Temp Range For 1976' 888 Mercruiser

Buy a thermostat with a known opening temp,and install it...That is, unless you know the opening temp of the one that is in there.<br />It's not overheating under 220, but it's good that you are watching this!<br />If it is out of the ordinary, something isn't right,and I suspect the thermostat opening temp.<br />If it's an auto thermostat, it's the wrong one. (learned that here myself). I think autop opens at 160, marine opens at 120...But not sure.
 
D

DJ

Guest
Re: Temp Range For 1976' 888 Mercruiser

russel,<br /><br />180 is not out of line.
 
Joined
Apr 21, 2002
Messages
15
Re: Temp Range For 1976' 888 Mercruiser

The thermostat that is now installed was a new marine 140 deg thermostat put in at the end of last season.
 
Joined
Apr 21, 2002
Messages
15
Re: Temp Range For 1976' 888 Mercruiser

djohns19, <br /><br /> thanks, i had called and asked a mechanic at a local marina and they had told me that the temperature should always be 140 or 160 depending on the thermostat installed, and that 180 was not good.
 
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