1984 Yamaha 90 HP alarm going off?

[wvmedic]

I have a 1984 90 hp Yamaha and was out on the lake today trying it out after rebuilding the carbs.

We idled threw the no wake zone and I throttled up to WOT the boat hadn?t gotten up on plane yet and the alarm started, had to back off on the throttle to near an idle and the alarm went off in a short while. When I would try to power up again the same thing would happen.

There was a steady stream of water from the tell tale, water was warm but there is a thermostat on the motor so I am taking this as normal. The cylinder head was hotter than I would have expected but not so hot that I couldn?t touch it, but I wouldn?t want to hold my hand on it for long.

Also after rebuilding the carbs I bled the oil pump and disconnected the oil supply line on the top carb, no oil from the line. I didn?t move the rod going to the pump as the manual said to but I would still expect some oil from the line at idle.

As a precaution I did pre mix at 50:1.

Any Ideas as to what the problem is likely to be?

Jeff.

 

[wvmedic]

Re: 1984 Yamaha 90 HP alarm going off?

I suspect the impeller but was woundering what the rest of you think.

Jeff.

 

[capt sam]

Re: 1984 Yamaha 90 HP alarm going off?

impeller, stuck poppit valve maybe, when you pull the poppit and thermostat check the head for salt blockage too.

 

[wvmedic]

Re: 1984 Yamaha 90 HP alarm going off?

capt sam, please forgive my ignorance but what is a poppit valve?

I have a good bit of automotive experience, but very limited marine experience.

Also I should have mentioned that this motor has been fresh water only motor.

Thanks Jeff.