1986 Johnson 150 GT: help replacing temp sensor

flight doc89

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Code on motor is J150STLCDC. I was riding down river when my alarm started a continuous buzz, but water was still peeing out motor. I trolled boat back to trailer and even after driving home, alarm would buzz whenever key was on. Unhooked and individually checked sensors, diagnosed a bad port side temp sensor.

So, I do a little research, instructions say to get the rubber grommet out and use a thin-wall socket to remove the sensor. I pull the grommet, and this is what I find (the wire broke while I was getting the grommet out).

Tempsensor.jpg


So...How do I get this thing out again? I don't see anything for a socket (or anything, really) to grab onto.

Thanks in advance for the help!
 

Joe Reeves

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Re: 1986 Johnson 150 GT: help replacing temp sensor

Socket??? No idea what you're speaking of.

Squirt a little WD40 in there and start picking around with a pointed scribe to break that salt corrosion up.

Note that on a V6, a fuel restriction will also cause the horn to sound constantly.
 

flight doc89

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Re: 1986 Johnson 150 GT: help replacing temp sensor

Socket??? No idea what you're speaking of.

Squirt a little WD40 in there and start picking around with a pointed scribe to break that salt corrosion up.

Note that on a V6, a fuel restriction will also cause the horn to sound constsantly.

So, spray some WD40, break the corrosion, and then how does it come out? just take some needle-nose pliers and try to ease it out?

When I disconnected the sensors, the buzzer stopped. Ground out either side to the block, and the buzzer starts. When I reconnect the starboard side, no alarm. But the moment I connect the port side sensor, buzzer starts, so I know it has to be that sensor.

Engine runs fine, fuel strainer is clean and flowing fine.

Thanks!
 

Joe Reeves

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Re: 1986 Johnson 150 GT: help replacing temp sensor

So, spray some WD40, break the corrosion, and then how does it come out? just take some needle-nose pliers and try to ease it out? The moment I connect the port side sensor, buzzer starts, so I know it has to be that sensor. Thanks!

That is a dead end hole and all that's in there right now is a rather flat plate that contains the sensor contact. As you break away the corrosion, that plate should simply flop loose.... needle nose pliers, piece of hooked wire, whatever will get it out so that you can clean the hole out properly. Good job of trouble shooting... bad sensor for sure.
 

flight doc89

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Re: 1986 Johnson 150 GT: help replacing temp sensor

That is a dead end hole and all that's in there right now is a rather flat plate that contains the sensor contact. As you break away the corrosion, that plate should simply flop loose.... needle nose pliers, piece of hooked wire, whatever will get it out so that you can clean the hole out properly.
Thanks so much :) Broke a pick and a pair of kobalts (which I will be taking back to Lowes for replacement :D ), but I now I got this:
Tempsensorremoved.jpg


Parts and books are on the way, gonna go ahead and replace spark plugs, thermostats, and clean out the head covers (packed FULL of sand :( ). Planning on replacing water impeller next week.

You got any other recommendations for maintenance while I'm working on my motor?

Good job of trouble shooting... bad sensor for sure.

Aside from my bogus information about using a socket to remove the sensor, I got all the information here. Thanks a lot guys!
 

wilde1j

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Apr 15, 2002
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Re: 1986 Johnson 150 GT: help replacing temp sensor

That may be sand, but also may be crystallized salt.
 

wilde1j

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Re: 1986 Johnson 150 GT: help replacing temp sensor

No, just running in saltwater. It also packs up around water pumps, especially on small motors.
 

boobie

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Re: 1986 Johnson 150 GT: help replacing temp sensor

When you install the new one, Put something like OMC gasket sealing compond around it to keep it from corroeding again.
 

Joe Reeves

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Re: 1986 Johnson 150 GT: help replacing temp sensor

Yep... what Boobie said.
 
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