Engine over heat after tow rope caught

[Jmpicking]

Before you do anything else be sure it is not a bad heat sensor I had one go bad, once the engine overheats it may damage a heat sensor. I believe that was how one of my sensors went bad, weeds overheated the engine and my son drove it in limp mode before he decided to remove the weeds, after that I had intermittent issues with warnings of overheating even on the hose but the non contact thermometer was not saying anything was actually hot so had one replaced and solved the issue. Either way have them checked or find the values and check them yourself

Okay, so I used an infrared heat gun for temperature one hose was much hotter than the other engine hose. Also the exhaust manifold felt extremely hot after running for like 2 minutes and the overheat alarm went off. So i dont know if it’s bad sensor.

But how can I test that?

 

[Jmpicking]

Hmm can’t find it anywhere

 

[Jmpicking]

Can I just measure somewhere specific on the engine to see if it’s actually overheating?

 

[Scottie]

Check the temp at the thermostat housing with your infrared. For both engines.

 

[Jmpicking]

There is a thermosensor and a thermoswitch which one am I looking for?

 

[Jmpicking]

I checked the hose leading to the thermostat housing and it was 20 degrees hotter than the other one

 

[Scottie]

What's the temp?

 

[Jmpicking]

127 degrees on the hose attached to thermostat after about 3 minutes on the hose, at that point the alarm is saying overheating.

Compared to 105 on the other engine

 

[Scottie]

Something isn't right. We don't have the same engines, but for mine, spec on the thermostat says it doesn't start opening til 136, with full open at 158. So you're getting overheat warnings in a situation where the thermostat would be normally closed. I don't know what to make of that. I'm questioning the sensor readings at this point.

 

[Cobra Jet Steering LLC]

I wish I could help with the heat sensor location I never owned a mr1 engine but if you check on green hulk forum someone would probably know and know the values for testing them I know my supercharged 1800 had several and the bad one was up by the intercooler so I had it replaced by the dealer under warranty

 

[Jmpicking]

Something isn't right. We don't have the same engines, but for mine, spec on the thermostat says it doesn't start opening til 136, with full open at 158. So you're getting overheat warnings in a situation where the thermostat would be normally closed. I don't know what to make of that. I'm questioning the sensor readings at this point.

I heard the thermostat isn’t the actual sensor that would sound the alarm, I thought the thermostat is just to slow or speed up the flow of water

 

[Cobra Jet Steering LLC]

2014 Yamaha AR210 (LAT1100AN) Electrical 2 | Babbitts Yamaha Partshouse number 4 and number 6 on this parts layout

 

[the MfM]

2014 Yamaha AR210 (LAT1100AN) Electrical 2 | Babbitts Yamaha Partshouse number 4 and number 6 on this parts layout

What about part #9? Another “thermo switch assembly”

 

[Jmpicking]

Those aren’t parts that u can just switch and put onto the other engine to try out though, are u suggesting taking it out and seeing if overheats?

 

[the MfM]

Those aren’t parts that u can just switch and put onto the other engine to try out though, are u suggesting taking it out and seeing if overheats?

Why can’t you swap them?

 

[Scottie]

I heard the thermostat isn’t the actual sensor that would sound the alarm, I thought the thermostat is just to slow or speed up the flow of water

That's correct. My point was the temperature you're reading there should be much much higher than 127 if the overheat alarm is going off. I don't know the exact limit, but overheat shouldn't occur until 170+, so I don't see how you could be overheating relatively cool water at that particular spot.

 

[Jmpicking]

Why can’t you swap them?

View attachment 96910

Woah well let me check again in the morning!

 

[Jmpicking]

That's correct. My point was the temperature you're reading there should be much much higher than 127 if the overheat alarm is going off. I don't know the exact limit, but overheat shouldn't occur until 170+, so I don't see how you could be overheating relatively cool water at that particular spot.

I dont know the water temperature coming out of that hose, but it was hot enough where I couldn’t keep my hand there for more than a 2 or 3 seconds

 

[the MfM]

Woah well let me check again in the morning!

These are from the fx140 service manual. Not sure if it’s the same engines. The values may be different but the procedure should be the same, or just swap them.

I have no idea if the “thermo sensor” or the “thermo switches” are responsible for setting the overheat alarm.

 

[swatski]

Different engine but also 2014

https://jetboaters.net/threads/14-242-exhaust-mani-water-leak-cold-vid-included.22420/

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