I need some help on this one???

I have a 92 Evinrude, owned it since it was new. After the freeze in Feb. when you drive up the lake 500yds or so. The solid horn alarm comes on. Which should mean the engine temp. Is too high.

I did away with the VRO oil injection years ago and just mix my oil with my gas at 50/1 ratio (1pint of oil to 6 gallons of mid grade gas). I also add 1 ounce of Yamaha Ring Free to every 10 gallons of fuel.

I took it to the shop and had the water impeller changed and the old one showed significant wear. Problem is the alarm still comes on, at 1100 rpms and 500 yds down the lake.

I siphoned all of the gas out of the tank and remixed 12 gallons of fresh fuel. Horn still comes on.

My next step is to take it back to the shop and have the temperature sensor changed out in case it is defective.

This motor has performed flawlessly for almost 30 years now with just regular maintenance on points & plugs.

Any ideas on what is causing this alarm to go off???

I would really appreciate some ideas!

I assume you have a good pee steam? Meaning the water pump is working. Do you have a water pressure gauge? As it does sound like an over temp alarm. I have a 1996 150 Johnson. Same motor pretty much. My water pressure gauge froze and busted during the freeze. So you might have and issue with water. Have you pulled the motor cowling and looked for leaks? Just a few thoughts.

Pee stream is good after the impeller change.

I’m hoping the heat sensor is bad. But it comes on after 500-600 yards going up the lake.

Any other thoughts on this?

thermostats? pop off valve? could be fuel press,hoses , primer bulb?

sounds like thermostat is bad and not opening.

you can pull them and check with a pan of hot water, look on top of ea. bank and you will see a round plug lookin thing, that is the thermostat/popet, pull one and put in a pan of boiling water and you should see it open pretty quickly, then do the other.

while you have them out, pour some clr (calcium/lime/rust) in ea. water jacket and let it sit overnight then flush with the muffs. if you can force it in with something like a turkey baster even better. it is possible that being that old the extreme temp changes loosened some build up and it has blocked one of the water ports.

I would start with the thermostat. Just check the simple stuff. The temp sending unit can be checked also. See if the freezing temps damaged something.

The first thing I would do is put my hand in the stream of water coming from the pee hole. If it is to hot you will know it. If not, then I would remove the brown wire from the sensor and see if the alarm quits. If it does, replace the sensor. Messing with the thermostats only works if the water is too hot on your hand.

The easiest thing to check is the thermocouple (sensor) itself. The other things require more mechanical effort. I owned an Intruder for years, and the only temperature warning I got was due to a failed sensor. It failed the test, so replaced and never had to look back.

I have working parts off my 91 cheaper than trying brand new... Text me 9728413278