Optimal running Temp for 74 650 merc

[imported_Rycher]

I did a search but couldn't find an answer..


What is the Optimal running Temp for 74 650 merc... any help would be appreciated..

 

[Texasmark]

Re: Optimal running Temp for 74 650 merc

How about 120-130 degrees F? I think that marine engines have to run cooler than their auto counterparts due to salt water scale that can buildup due to water evaporation at higher temperatures.

The thermostat pellet in my 90 3 cyl is stamped 120 (starts opening). The overtemp sensor is at either 165 or 195....forgot......probably 195 as you need some room for tolerances to build up.

HTH

Mark

 

[Chris1956]

Re: Optimal running Temp for 74 650 merc

Rycher, Does that motor have a thermostat? Most inlines don't. If no thermostat, then it will run hotter or colder depending on the temp of the water and how hard you run it. The plan is not to overheat it by lugging it, or having a bad impeller, or clogged carbs.