Engine Temp

[Mystiko]

What should the temp gauge read on the Yanmar 4JH2 50hp from 1996. This powers a 40’ Sailboat, currently the temp gauge reads 190 degrees after warming up and running at 2,500 RPM’s. Is this correct? If not what should the temp gauge read. Please email me if you know, thanks, jeffrey54@comcast.net

 

[Stu Jackson]

It depends on what temperature thermostat you have installed. There are two: 160 & 180 for Universal engines, perhaps yours, too. Engines usually run a few degrees warmer than the stats.

 

[Don S/V ILLusion]

The OEM thermostat for your engine is 180 deg. Whether or not you have that thermostat, as Stu suggests, is the determining factor on what temp your engine will run.

 

[larryw]

190 is right on the money for operating temp.

 

[Gary_H]

My little 5411 runs at 150 but I'm strictly sea water cooled.

 

[sailaway78]

That sounds pretty close to right, maybe a few degrees high. The alarm buzzer for the fresh water cooled engines is set for 200 degrees.