Testing thermostat

[lp142]

I think my thermostats are bad, most of the time the exaust water is cool to the touch, only one time it was really warm. Is there a way to test the thermostats, I have a 1978 Johnson 140HP. Also I am new at this so excuse my stupid question but what is WOT.

Thanks

 

[ezeke]

Re: Testing thermostat

WOT is wide open throttle, variously used for throttle arm full down, optimum operating RPM, optimum full throttle RPM range, depending on who is talking.

What it used to mean was that the throttle plates in the carburetors were fully open, allowing the maximum RPM.

Test your thermostats in a heating pan of water with your meat thermometer in the water. The thermostats are usually either 105 or 143 degrees as marked on the thermostats, though you may need a magnifying glass to see it. You will see them open and can verify the temp at that time with the thermometer. More than half the time you find it isn't the thermostat or vernatherm, but all the accumulated junk in the thermostat housing that causes the problem. Some motors have problems with the seats for the thermostats as well.

 

[Windykid]

Re: Testing thermostat

I open the thermostat a bit and pass a string through it. Then suspend it in the heating pan. When it falls to the bottom of the pan check the temp and you will know when it opens.



Remember a watch pot never boils

 

[johnson1989]

Re: Testing thermostat

I did the same as windy and found a bad stat in my motor, I used a laser temp tester to watch when they opened.

 

[omcgreasemonkey]

Re: Testing thermostat

semple solution i pulled mine they have no buisness in a saltwater v4 crossflow but replaced the poppit valves ,director tubes and headgaskets this thing sat on the water for a long time and the owner never flushed i can pull t-stats due to my weather here in fla its never coldenough to need em but my sugestion is if its saltwater ran pull em out