2001 60 hp 4 stroke overheating

[djinva11]

I just sold my pontoon to my brother. I had it several years and never a problem. It is a 2001 60 hp Yamaha 4 stroke. We used it last fall and everything was fine. . When he put it in the water the alarm went off. He had started it in the driveway on muffs. We figured it needed a an impeller. He put a new impeller in it which it needed. It runs 4 minutes before the alarm goes off. He pulled the thermostat it is working fine. It is peeing a good stream, but continues to set the alarm off after 4 minutes. We cannot find a blockage,

Any help would be greatly appreciated.
Thanks

[djinva11]

It is a F60tlr

[TownsendsFJR1300]

The OLD impeller, was it missing ANY PIECES?


Salt or fresh water use? Hours on engine, especially if NOT flushed after salt water use?

.

.

[djinva11]

Fresh water use only its whole life. I am not sure of the hours. I would guess only a few hundred, it was my father in laws boat and he passed.

[99yam40]

looks like the motor was ran without any water to the pump,
the rubber impellor is shredded and there is probably pieces of rubber up in the power head not allowing water to flow where it should be.

I would drop the lower unit, pull the stat and housing, hook up a water hose to the pipe heading up to the power head , and then turn water on full blast to see if you can flush some stuff out.
rigging up compressed air to the water line so you can blast some air into the water stream from time to time might help move some stuff around.

If you cannot get it cleared, then the head and exhaust cover plate will probably need to be pulled to find what is plugged

[TownsendsFJR1300]

What 99 said...

The old impeller is in and about your cooling system causing havoc..

.

[zenoahphobic]

Yes picture tells the story.
Hard to believe that there was that much heat created to completely melt the arms off!

[djinva11]

Look how clean inside, we still cannot find the blockage. Please give me your thoughts.
Thanks

[panasonic]

Take LU off and hook a garden hose directly to the water tube in the leg too see if you are getting water up through the head.

Not sure if you can run that engine without the drive shaft/LU removed. Some engines require the LU in place to drive the oil pump...that was brought up here recently.

If you get water with hose hooked up to water tube, then go back and make sure you have the new impeller installed properly...not hard to put them in backwards!!

[panasonic]

Super clean engine...can't have been in salt water much.

[djinva11]

It is getting water up through the head. It has never been in salt.

[mrozborn]

What do you mean "install them backwards"? You mean the direction of rotation? Or is there an up and down side on the impeller? When I took mine apart it appeared the impeller was running clockwise looking down at the lower unit. I installed same way.

[99yam40]

I am sure he was talking about rotation direction.
but I have seen impellors where the notch for key was not all the way thru, but in my opinion should have been.
I not sure if the impellor has a correct top and bottom

[djinva11]

Flushed it out again and put it in the water and it is fine now. We didnt see anything but evidently something had it stopped up. Thanks for all your input.

[99yam40]

that is good news,
but it is much more rewarding to find something that is the problem and fix it
hope it is gone for good.

anyone admit to running it without water?