Mercury tracker 40 hp 2 stroke overheating

[kyleechert]

Hi, i have a 1995 mercury tracker pro series 40 (4 cylinder). I was cruising when all of a sudden the overheat alarm started going off. I pulled over to the bank and shut her down. The tell tale was peeing a strong stream of water the whole time. The cylinder head felt hot to the touch but not what I would consider to be hot enough to cause serious damage. I waited for it to cool before attempting to restart. She fired up and ran for about 30 seconds and the alarm went off again while still peeing a strong stream of water. I also checked the oil reservoir and it is full. Plus it smokes like a 2 stroke should, so I know its getting oil. What should I look at first when attempting to diagnose this issue?

 

[BigOtuna]

I would test some sensors in various temps of water with a voltmeter to make sure they are reading correctly! Also take a look at your thermostat(s) to make sure they are opening up. Is the water coming out the pee hole hot?

 

[kyleechert]

The water stream is pretty strong out the pee hole. It is also pretty hot. Not boiling but definitely hot. From what I've seen online, it does not appear my motor has a thermostat

 

[BigOtuna]

The water stream is pretty strong out the pee hole. It is also pretty hot. Not boiling but definitely hot. From what I've seen online, it does not appear my motor has a thermostat

Does it have a poppet valve? Like increase stream with rpm?

 

[kyleechert]

From what I've seen on repair manuals, it does not have a poppet valve. Im starting to think its a bad sensor

 

[BigOtuna]

Nice! That will be a pretty simple test. A few nice you tube videos can help you out!

Keep me posted