Engine Overheating

[jetboater40]

We are the owners of a 2015 Yamaha AR192.

We were on the water today enjoying one of the last few days before the end of the boating season.

I was cruising at 6000 rpms (20mph) and then decided to increase to 7000 rpms (30mph).

I cruised at 7000 rpms for approximately 10-15 minutes before we I decreased the speed to 20 mph.

Once we arrived in the bay, I further decreased the speed to 10 mph.

At that point, the engine overheating warning activated.

Water was streaming from the pissers, however.

I let the engine run for approximately 1 minute, turned it off, anchored and then started the engine but remained at idle.

The warning was no longer present.

I then turned off the engine and checked the clean-out plug and found a few small pieces of river weed.

The boat is properly maintained.

Any thoughts as to what caused the overheating?

 

[WREKS]

I would search 'overheat' and read the threads that address your boat model and year. Making yourself aware of how the cooling system works in your particular boat will help. You started at the right place by checking the cleanout.

 

[jetboater40]

Thanks!

Happy to report that I took the boat out today (same air and water temps as yesterday).

I cruised at 7000rpms for approx. 10 mins and no overheating.

I also cruised at 6000rpms for approx. 10 mins and then 6500rpms, without any issues.

I question if something was in the intake yesterday.

I also reviewed previous forums for our model with the subject "overheating".

I checked the oil level, all was good.

Checked the pissers, all was good.

 

[Gym]

The few pieces of river weed you found were likely part of a larger clump that dropped out when you shut down. This is not untypical. You may have noticed a slight vibration or a slightly different sound while at speed. That sound or vibration would have been cavitation which would have been your first indication.

I have developed a very keen ear for this noise while getting deafer to my wife's noise. Can't seem to explain it. Might be natures way of self preservation I guess.

 

[jetboater40]

LOL

Actually, my wife did say the engine was making a buzzing sound.

She thought the clean-out plug would burst.

I can generally hear a variation in the engine sound but I guess not yesterday afternoon :-(

While testing the boat today, I heard nothing other than the engine's usual sound.

High temps in our area this summer caused a great deal of river weeds.

I am frequently cleaning out the intake from weeds, very frustrating but better than diving under the boat.