1998 yamaha waverunner xl760 over heating please help

[ohiojetskigirl]

Hello, I am in some help! My 760 is over heating. Symptoms I know of that is different from my other jetski same make and model/year as this one.

It ran fine then out of nowhere the temp gage starting going off. If I keep it under 25 or 30 mph it doesnt seem to come on. But after a few minutes of faster speed it comes on. Let it set for a bit and its fine until I go over 30mph or so and it repeats.

The side where the water comes out (from the pee spout) isnt a steady stream. Its like it spits quickly but not steady stream. Like its being interrupted. My other ski flows with no interruption. As well the water that does come out it alot hotter than the water that comes out of the good running ski. Not sure if that's relevant by there is a big difference in their temps.

I have been told it could be alot of different things and am hoping someone on here maybe able to guide me on how to start checking on what all it could be.

Also does this particular make and model have a thermostat? If yes do you know where its located?

Thank you so much!!!

 

[sixfigures]

Re: 1998 yamaha waverunner xl760 over heating please help

Yamaha is known for defective heat sensors, when the ski acts up do a thermal reading on several parts using a non contact thermometer this can tell you if there is a place on it that is getting hot. Compare those readings to the other ski or to the ski when it isn't running hot. Also use some compressed air to blow out the cooling hoses but do not use a lot of air pressure.
To locate the thermostat look for the main exit hose that goes from the engine back to the exterior of the boat, the thermostat is usually behind a cover at the engine where that hose attaches.
You may also have a water flow issue in the exhaust system, or the jet pump filter where the water goes from the pump to the initial cooling hose, there is a perforated plate to screen out large weeds etc.

 

[jafo9]

Re: 1998 yamaha waverunner xl760 over heating please help

the pisser is there for a reason. if you see a different flow pattern and temp in the exit water, i'd for the moment assume the temp sensor is correct. the cooling system on these things is pretty simple and pretty easy to flush. the manual will usually give you instructions on how to flush the system. my guess is that you've got a clogged port somewhere and you are truly overheating. fix it now before you cause permanent damage.

 

[MikDee]

Re: 1998 yamaha waverunner xl760 over heating please help

I used some green weedwacker line to clean out the pisser each year on my old Yamaha 1100 waverunner.