# 1989 Evinrude 150 Crossflow Thermostat Question.



## Kenton (Nov 16, 2007)

Ok so i was running the engine on the muffs yesterday and i touched the port side of the block and it felt a little warm, not bad (thermostat possibly stuck open? Checking today after work). Felt the starboard side and it about left a blister. I turned off the engine and opened up the thermostat housing on the starboard side. Thermostat was dry on the backside that opens to let water through. But my tell tale was peeing just fine. Should the tell tale pee if the thermostat is not opening? I think it is time to replace both thermostats just to be safe. They are super easy to get to.

I looked inside and did not see any major salt build up. Just a slight bit of wall crud. Maybe a mm or so. Salt away or vinager to be safe?

I am def going to replace the thermostat but would like to test it to confirm my theory of it not opening up. Do i do this just like a car thermo, in a bowl of boiling water with a thermostat? 

Thanks.
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## fish4life (Mar 3, 2008)

*Livingston outboard rebuilds and repair*



Kenton said:


> Ok so i was running the engine on the muffs yesterday and i touched the port side of the block and it felt a little warm, not bad (thermostat possibly stuck open? Checking today after work). Felt the starboard side and it about left a blister. I turned off the engine and opened up the thermostat housing on the starboard side. Thermostat was dry on the backside that opens to let water through. But my tell tale was peeing just fine. Should the tell tale pee if the thermostat is not opening? I think it is time to replace both thermostats just to be safe. They are super easy to get to.
> 
> I looked inside and did not see any major salt build up. Just a slight bit of wall crud. Maybe a mm or so. Salt away or vinager to be safe?
> 
> ...



Just take them out and leave them out.


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## Kenton (Nov 16, 2007)

Really? Wont that effect gas milage and start up conditions?


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## Kenton (Nov 16, 2007)

I think i talso will hurt my pistons and fowl plugs. I am going back to thermostats.


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## TheCaptKen (Mar 14, 2011)

Do not run without thermostats. The oil will not burn off properly and will cause a carbon problem otherwise called coking. If you had a thermostat stuck open on the other side, it would rob water from the good side. Replace both thermostats and be sure the relief valves are not stuck open or shut.


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## Kenton (Nov 16, 2007)

I am going to get a full Thermo kit from Iboats.com that replaces all components of the housing and thermostat. To include pressure relief valve.


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## Kenton (Nov 16, 2007)

Thanks for the advice Capt Ken!


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## Kenton (Nov 16, 2007)

Wirelessly posted (Matt)

I afraid of this. Tested the thermostat on the hot side and it was not opening. What kind of damage could I have done? It Was still running strong when I removed them.


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## Sequoiha (Sep 28, 2007)

fish4life said:


> Just take them out and leave them out.


 Not good advise at all,, come on shane lets think about this...


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## floater1 (Oct 31, 2007)

I am currently running a 92 yamaha 200 no thermastats none in my truck either just relieves another problem will not over heat some other people may argue this point i have had 3 outboards none with thermastats and never had any problems with running hot


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## Kenton (Nov 16, 2007)

Wirelessly posted (Matt)

I rePlaced them. Running great now.


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