Evinrude Temp sender retrofit

[Brendanpd28]

Hey all,

    Looking for tips from other aquasporters with older outboards like myself. Motor is a 1990 Evinrude 88 SPL.  Just like last year, my overheat alarm went off during spring commissioning. Last year I replaced the thermostats AND waterpump. Tell tale water was not warming up which led me to think the tstats were stuck closed. I removed the hoses connecting the tstat housing to the cylinder banks and got some vinegar down on the tstats and compressed the springs a few times.  Re-ran the motor for about 15 minutes at idle and it DID NOT overheat this time but the water is still very cold.....odd?  I'm thinking about installing a temp gauge to monitor cylinder temp so I can keep an eye on it BEFORE the alarm sounds. I've seen some senders you can just thread into a spot on a cylinder and run a sender wire up to the gauge.  But i am also curios about this from Simrad
://www.simrad-yachting.com/simrad/type/accessories/temp-sensor-pk/?gclid=Cj0KCQjw8YXXBRDXARIsAMzsQuXjxUUawperCV_e9dlG7s8_6mR4ZvNh4NwrXkV_H0YEx2SARUjUWcAaAiLfEALw_wcB.
I could simply connect this into my N2k backbone but I am not sure where to mount it for the most accurate readings across all four cylinders.  Any input here?

Thanks as always!
   

[wingtime]

I'd look where the sender is for the system check alarm.  Then I'd place it near it or in the same location on the opposite head.

I'd also get a look into why your getting the overheat problem in the first place.  Unless your water pickups are clogged these motors should not overheat.  Even down here in the hot water overheating is a non issue.  Your pee indicator usually has nothing to do with the thermostats.  I believe it is just when the crankcase cooling passages are full that is starts to pee.

Are you getting overheat on the muffs or in the water?  Also I'm not sure if that motor has a pressure release valve or not.

[Brendanpd28]

 There is a wire that comes out of each cylinder bank which connect to the overheat alarm so it will signal if either has an issue.  I think there is some sort of bypass so the water still has a place to go if the thermostats do not open properly and let water into the cylinders. That’s why I figured the P stream was staying very cold even when the motor was coming up to temperature.  I ran salt-away through the system a couple times and then I actually had the opposite problem, the cylinders were not coming up above 100° but the P stream was still cold which makes absolutely no sense to me.  Either way, I ran the motor for a long time this weekend and did another salt-away treatment in the cylinders appear to be running at proper temperature now around 140° so maybe there was just a lot of buildup in the passages. I also did another seafoam treatment  which got the motor running a lot smoother. I think I used way too much fogging oil when I winterized as well. This was on the muffs by the way..and there is a pressure relief valve in between the 2 thermostats. I appreciate the help.