78 evinrude 115, one side getting hotter than the other???

[BigBassin78]

When I have the engine cowling off, the left side of the v4 gets quite a bit hotter than the right. There seems to be good flow through all cooling system outlets. I can hold my hand on the right side indefinitely when the motor is at operating temp. I can only hold my hand on the left side for about a second. Could there possibly be an obstruction in the cooling system. Should I not run it until I figure this out, or is it normal? I have not had an OH horn go off, then again I dont even know it even works. Is there a way to test the overheat horn? Thanks for all's input!

 

[Haffiman]

Re: 78 evinrude 115, one side getting hotter than the other???

My guess is that the 'hot' side is the correct one, your trouble is on the cold side.
Pull out the thermostats (in the housing below the exhaust cover) and check. One is probably permanently open. If so, change BOTH!
Yes, I know they are a bit tricky to get at, not to mention to get back, but that is the game.

 

[emdsapmgr]

Re: 78 evinrude 115, one side getting hotter than the other???

That engine has two thermostats, one controlling the temp on each head. One of them is obviously not working properly and needs to get changed. Since they are both located in the same housing, why not purchase two new stats and change them both out at the same time. That engine should idle between 143 and 150 degrees-if you have a laser temp gun-measured at each head. Since this is a flatback engine, you should not have much problem accessing the thermostat housing.