How do I get temp sensor out? Evinrude 120

[archcycle]

88-91 evinrude 120hp, a local guy replaced my port head with one he had lying around because it looked in better shape than the one I had. Now per help from this forum I am diagnosing for SLOW issues. Checked my overheat alarm and both sides made it sound when I grounded them so.
EDIT: Won't go over 2300 indicated on the tach, no stammering or going above it, that's just it.

Question 1: What if the head he put on was from a starboard side of it's last motor and it therefore has the starboard temp sensor which I assume is different because it's $60 cheaper than the port sensor? Can this cause SLOW to engage if it's not getting something from this sensor it ought to?
EDIT: my previous port head had the part number on it, the starboard has a casting number stamped on it and no part number. This 'new' port head also has a casting number on it but no part number (port ends in -4 starboard ends in -3).. hmm..

Question 2: How do I get that temp sensor out? I removed the threaded rubber cover with an open face wrench like the manual said, but then it says to thread out the temp sensor... but it's a flat faced piece or rubber deep in the hole. Am I supposed to use something with teeth to back this out? A gentle tug told me I probably don't pull it out..

Question 3: Once I get it out can I expect to find a part number so I know if I need to buy a proper port side sensor?

and lastly, depending on whether it would even engage SLOW if I had the wrong temp sensor in the port side, would having a sensor in there that wasn't throwing the alarm even engage SLOW?

 

[archcycle]

Re: How do I get temp sensor out? Evinrude 120

Bump.

How do I get that temp sensor out once the rubber cap is off?

 

[daselbee]

Re: How do I get temp sensor out? Evinrude 120

The port temp sensor has two thermal switches in it...one for the tan overheat signal, and one for the white/black Quickstart sensor. Tan closes at around 200 degrees, white/black closes at around 95 degrees. (This is from memory...look it up if you need exact numbers.) The starboard side only has one switch....the tan overheat sensor. That is the explanation for the price difference.

Both heads are the same and will work on either side. The -3 and -4 you are seeing I believe is the number of the head bolt next to it. Look and see if the rest of the head bolts have numbers next to them. (Again...from memory, can't be sure on that one.) The six digit number that you are seeing is a casting number, not the OMC part number.

I take the plastic cap off, and use a sharp 90* pick to get in behind the rubber seal, breaking it loose all around the metal hole surface. Then I gently try to ease it out with the pick. If you pull on the wires, you will likely be buying a new temp sensor.

 

[daselbee]

Re: How do I get temp sensor out? Evinrude 120

88-91 evinrude 120hp,
Question 3: Once I get it out can I expect to find a part number so I know if I need to buy a proper port side sensor?

and lastly, depending on whether it would even engage SLOW if I had the wrong temp sensor in the port side, would having a sensor in there that wasn't throwing the alarm even engage SLOW?

Sorry...didn't answer all your questions.

Only one part number for the port temp sensor. Look your engine up on shop.evinrude.com and get the number. Available from Evinrude parts only.
If you have a temp sensor with both wires in the port head, you have the right sensor.

The engine will go into SLOW mode when a temp sensor closes at about 200 degrees AND the alarm will sound. Both events occur.

 

[archcycle]

Re: How do I get temp sensor out? Evinrude 120

Sorry...didn't answer all your questions.

Only one part number for the port temp sensor. Look your engine up on shop.evinrude.com and get the number. Available from Evinrude parts only.
If you have a temp sensor with both wires in the port head, you have the right sensor.

The engine will go into SLOW mode when a temp sensor closes at about 200 degrees AND the alarm will sound. Both events occur.

Thanks!

 

[archcycle]

Re: How do I get temp sensor out? Evinrude 120

The port temp sensor has two thermal switches in it...one for the tan overheat signal, and one for the white/black Quickstart sensor. Tan closes at around 200 degrees, white/black closes at around 95 degrees. (This is from memory...look it up if you need exact numbers.) The starboard side only has one switch....the tan overheat sensor. That is the explanation for the price difference.

The port side has one tan wire, as does the starboard so I have no quickstart. Would having no quickstart sensor activate SLOW? I have verified my alarm works.

 

[daselbee]

Re: How do I get temp sensor out? Evinrude 120

The port side has one tan wire, as does the starboard so I have no quickstart. Would having no quickstart sensor activate SLOW? I have verified my alarm works.

Lack of a white/black QuickStart wire should not activate SLOW. The powerpack sensing the 200 degree overheat from the tan wire will trigger SLOW.

Have you checked at the pack for the pack-side white/black wire? The wire where the temp sensor side would normally connect to?

At 95 degrees, the white/black wire from the sensor will switch to ground. You could take the white/black pack side and jumper it to ground, making the pack think the engine temp is at or above 95*.

Then, if QuickStart is working properly, when you start the engine, it will idle up at around 1100 rpms for about 5-10 secs, then you will hear it drop down to normal 700 rpm idle. It is very clear and easy to hear it race up, then drop down. You could test the function that way until you get your correct port side temp sensor. I am wondering if you even have the right pack. If you don't have the pack-side white/black wire....maybe not even the right pack.

AND....maybe you don't have QuickStart at all. I do not know the year they implemented QuickStart on the 120 loopers. You will want to check that first I would guess. Someone here will know the exact year...Ezeke....