80 hp AETO 1986 2 stroke over heating

[Needles]

I have a 1986 80hp AETO.
The problems are as follows:
When the engine is running on a water flush it seems ok, but as soon as it is put in the sea and under load the buzzer goes of
I put this down to over heating so change the water impeller but still the same problems. I also added oil straight to the fule tank incase it's the oil sender thingy. Which is where i got stumped because when i got the boat back to the yard to flush the engine out with fresh water ,it would not turn over at all. As if it was seized . After a few goes it did turn over , i flushed it out for half a minute .
When under load at about 1000 rpm it will run (with buzzer going off) but any more revs and it will studder, Is this down to the engine going into a safe running mode ?

Thanks for Any help

 

[Needles]

Re: 80 hp AETO 1986 2 stroke over heating

Any idea anyone

 

[99yam40]

Re: 80 hp AETO 1986 2 stroke over heating

Find out if it is oil or temp causing alarm by disconnecting wires when the alarm is sounding. Temp switch should be pink wire,but not sure for that old of motor. Do a search for that problem and get a manual for your motor it will help.
Temp problems are usually thermostat and/or water pump, but can be blockage internally.
If it is oil you may have scored the pistons and cylinders already. So check compression first.

 

[Needles]

Re: 80 hp AETO 1986 2 stroke over heating

Hi
I have changed the impeller and water is coming out very quick. I am going to check the compression this week end, fingers crossed it will be ok.

Thanks for the help

 

[99yam40]

Re: 80 hp AETO 1986 2 stroke over heating

pull the thermostat and test in a pot of water to see what temp it is opening at if it is at all.

 

[Needles]

Re: 80 hp AETO 1986 2 stroke over heating

Thanks for that 99yam40.
I will give it a go over the weekend and will let you knowhow i got on .