Control Box Alarm Buzzer, drives me crazy!

[bnt5]

I have a 1989 Evinrude 30hp outboard with remote console, the problem is that while idling along after about 3 minutes or so, the control box starts emitting this awful loud buzzing sound. I can get it to go away if I throttle up and run the engine like this for a few minutes. I believe this is an overheat sensor, however when I am idling the motor is peeing a stream out just fine and also blowing out warm water and exhaust at the back. I know it isnt clogged and its getting enough water so what should I do besides not idle? Is there a way to disengage this alarm and will it cause problems with the motor running?<br /><br />Thanks<br />Bill

 

[Walker]

Re: Control Box Alarm Buzzer, drives me crazy!

When was the last time you changed the water pump and thermostat. At idle the circulating water has to go through the thermostat to cool the motor. At higher RPM's the water pressure from the impellor is increased and forces open the cooling bypass valve so there is a greater cooling flow than just through the thermostat. <br />Since your motor seems to be cooling at higher RPM's I suspect your thermostat is clogged/corroded/stuck or bad.

 

[Silvertip]

Re: Control Box Alarm Buzzer, drives me crazy!

It amazes me that you would want to disable the very system that is telling you something is wrong. Sort of like removing the bulb from the OIL pressure light in your car because it came on. Fix the problem -- don't disable the alarm system. It's one of those "pay now" or "pay a bunch more later" scenarios.

 

[OBJ]

Re: Control Box Alarm Buzzer, drives me crazy!

Hi Bill and welcome to iboats.<br /><br />What ya' need to do when your idling along and you get the warning horn is pull the cover and see if you can lay your fingers on the flat place on top of the block just forward of the head. If you can't lay your fingers there for several seconds, the engine is overheating. Even though you got a good pee stream, the t-stat could not be opening far enough OR your impeller is not pushing enough water at idle to cool. Let us know what ya' find.

 

[seahorse5]

Re: Control Box Alarm Buzzer, drives me crazy!

Check with a dealer, I believe there were some service bulletins about occasional overheats with the 30hp block back in those years. <br />You will still have to replace the water pump and thermostat to be on the safe side.