Help solve this problem: overheat alarm

[jlcj7]

A neighbor of mine posted this message:

"We started to have an engine overheating alarm and goes into limp mode, the engine can be cold and still gives the alarm. I suspect it's a bad engine temp sensor. I searched the web and couldn't find a service manual. It's one of the two engine temp sensors went bad. Which I haven't been able to find on the engine."

I told him to check:

• water coming out of pee-holes
• clean out plugs to insure nothing in there
• disconnect/reconnect battery to try to clear code
• spark plugs (still dont understand this one, but have read numerous people having overheat issues that went away after changing plugs)

It may actually be a temp sensor as well of course, but is there anything else i am missing...

Also quick question... I have a YDS i use on my 2011 boat... does this work on newer Yamahas (i.e. 2014-2016?)

 

[su laxplayer21]

I had a temp sensor that went bad, the one that is on the exhaust manifold. The best way to rule this out is by swapping from the bad motor over to the good motor. If the code follows it, then you know it is a sensor.

 

[Bruce]

The only overheating experience that I have had was due to cavitation caused by debris in the jet. That is what I would check first.

The intake for the cooling water is neat the back of the jet on the left side. It has a filter / grate than can be clogged. It is inside rectangular housing on the outside of the pump. He can remove four bolts to remove the cover to access the plastic grate for cleaning.

 

[jlcj7]

I have the YDS with the 1.33v software... Does this work on 2015 boats?

 

[KXCam22]

I had an overheat from leaving the tow valves closed. Dummy! Got an engine temp lockout on both engines. It took disconnecting the battery to reset and restart. Cam.

 

[Cobra Jet Steering LLC]

I had a bad sensor that would go off even when the engine was just started and cold, Yamaha has had a reputation for bad sensors mine was replaced under warranty and I was quite happy that they replaced the sensor and the problem went away.