Warning Buzzer

[lucky01]

Hi all.. I have a 1989 Yamaha 70hp outboard that was rebuilt approximately 5 years ago but not done a huge number of hours since. Lately I encountered a problem where the warning buzzer gors off and engine revs drop dramatically until the buzzer stops. I realise this action is normal but am unable to find the cause. The cooling system seems to be working fine and no sign of corrosion internally. Can anyone suggest where I might look next and has anyone else had this problem and what fixed it?

 

[99yam40]

Re: Warning Buzzer

You need to find out what is bringing in the alarm.
I am not sure what all will bring in the alarm for that model, but I know temperature will. If it is oil injected there maybe some alarm associated with that.
When was the last time you changed the water pump and thermostat?
They are something that needs replacing every year or 2 as preventive maintenance along with the pressure relief valve if there is one.
The thermostat and the temp sensor are easy to test in a pot of heated water to make sure they are functioning as they should.