How to check thermostat

Hoyt79

Petty Officer 2nd Class
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Mar 26, 2011
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172
got a 1972 50 hp johnson...how do I check the thermostat?
 

BonairII

Commander
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Jun 7, 2011
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2,727
Re: How to check thermostat

Pull the thermostat and put it in hot water. If your thermostat is like mine(1977 75hp Evinrude) the t-stat should start to open at 145 degrees.
 

Hoyt79

Petty Officer 2nd Class
Joined
Mar 26, 2011
Messages
172
Re: How to check thermostat

Pull the thermostat and put it in hot water. If your thermostat is like mine(1977 75hp Evinrude) the t-stat should start to open at 145 degrees.

where is my thermostat and how do i remove it?
 

BonairII

Commander
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Jun 7, 2011
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Re: How to check thermostat

You may end up needing a new gasket(s) after you pull off the housing.
 

OLDIRON

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Apr 2, 2008
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Re: How to check thermostat

I wouldn't pull the thermo on that motor unless I had elimintated all other issues. Is it overheating? There's alot of things that can cause overheating besides a themostat.
 

BonairII

Commander
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Jun 7, 2011
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2,727
Re: How to check thermostat

You talking about a new head gasket? I have to pull off the cylinder head?

No. The t-stat housing gasket. Mine was in bad shape and came off in pieces.

Doesn't hurt to check you thermostat regardless of whether it's the cause of problems. If it's old, it's not a bad idea to replace it. They're only $20 bucks.
 

Hoyt79

Petty Officer 2nd Class
Joined
Mar 26, 2011
Messages
172
Re: How to check thermostat

No. The t-stat housing gasket. Mine was in bad shape and came off in pieces.

Doesn't hurt to check you thermostat regardless of whether it's the cause of problems. If it's old, it's not a bad idea to replace it. They're only $20 bucks.

I don't think that there is anything wrong with it...I took my boat out twice this weekend and ran long enough to burn a tank of gas in it and it was fine with water coming out the exhaust ports, but I just wanted to change it out because it probably hasn't ever been done.
 
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