replacement high-temp sensor - 60's Johnson

H

highangle

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Found that my 60hp Sea King does not have a high-temp sensor on the motor. There is a "overheat" light on the dash, but the wire is capped inside the engine cowling.

Have not been able to locate one outside of doing a full temp guage. Anyone know of where to get one?
 
Joe Reeves

Joe Reeves

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Re: replacement high-temp sensor - 60's Johnson

I may have a few left in stock. What year is that 60 hp, and is there a place for the heat sensor in the cylinder head(s)?
 
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highangle

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Re: replacement high-temp sensor - 60's Johnson

Thanks Joe - from the model/serial #, it should be a 1963. Model GG18808B.

Is it threaded? I can't find anyplace on the head that isn't screwed into already...

There are a couple of clips that don't have anything in them.
 
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Joe Reeves

Joe Reeves

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Re: replacement high-temp sensor - 60's Johnson

No, it's not threaded. There should be a location on the cylinder head, a hole of sorts which would be approximately 5/8" in diameter and about 3/4" deep or so. The overheat sensor fits in there and is held there by the head cover plate...... the plate must be removed in order to install the sensor.

If the sensor is already there, it shoulld have a TAN wire protruding from it.
 
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highangle

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Re: replacement high-temp sensor - 60's Johnson

I'll have to look a bit closer. The head is what the plugs screw into, right? and there is supposed to be another cover over that? Which side of the engine is it usually on? Will I need to replace a gasket to install?

I have a tan wire that is capped inside the cowling. Traced it to the point that if I ground it, the overheat light goes on.

thanks again.
 
Joe Reeves

Joe Reeves

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Re: replacement high-temp sensor - 60's Johnson

Yes, you'll need to replace the water jacket cover plate gasket.... no big deal.

That tan wire would connect to the sensor. If the engine starts to overheat, before it overheats to a damage point, the sensor will gound out and the overheat light will light.

See fig 29 gasket, 30 plate, 35 sensor as listed below.

68_100-PH-1.jpg
 
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F

F_R

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Re: replacement high-temp sensor - 60's Johnson

Don't go nuts looking for it. I think that you will find that the Gale 60 does not have a place for such a sensor.
 
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highangle

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Re: replacement high-temp sensor - 60's Johnson

hmm. That might explain things. maybe this boat was repowered? It is a 1961 Seaswirl, with a 1963 Sea King, Johnson controls and wiring box.

Found that under all the grime the tan wire goes to the magneto cutout switch, and the one I thought was tan is actually yellow when I pulled back the harness...

Guess it might mean doing a real temp guage this winter then...
 
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