Alarm in control box

[ronn07]

Motor is a 2000 Yamaha 90 HP 2 stroke. Oil tank has been removed and I mix oil and gas to a 50:1 ratio.

We took the boat out last weekend and had an issue come up with the alarm in the control box.

Right after launching the alarm goes off, mind you this is Minutes into the boat running. I pulled the cowling and touched the motor - cold. Water was 53 degrees so overheating that fast is very unlikely. While the alarm is going off, the motor goes into limp mode.

I figured out if I Kill the motor, and restart with a high idle for about 20 to 30 seconds, the alarm goes off, and the motor runs fine, until we slow down again.

I am thinking it's the impeller or a blockage which I plan on replacing this weekend. The tell tail never stopped and the boat never actually got hot. It warmed up to operating temps, but never to the point where I was afraid of damaging the motor.

What else could it be?

Thermostat or pop it valve?
Fuel filter clog? Replacing that this weekend too.

Thanks in advance.

 

[QBhoy]

Hi. As far I know, it can only be overheating or an oil associated alarm. Is the oil tank float switch disabled or cable tied up/tank left full ? Could also be an electrical issue of course

 

[ronn07]

Hi. As far I know, it can only be overheating or an oil associated alarm. Is the oil tank float switch disabled or cable tied up/tank left full ? Could also be an electrical issue of course

i believe the oil alarm was removed when they took the oil tank off. And this was the first time I ran it this season. Last time was in Sept before winter set in. It never had the alarm issue before now.

 

[QBhoy]

i believe the oil alarm was removed when they took the oil tank off. And this was the first time I ran it this season. Last time was in Sept before winter set in. It never had the alarm issue before now.

I’d have a look at the oil tank level perhaps. Likely make sure it’s been properly disabled too. Some guys stop it from alarming, by just leaving oil in the tank. Even seen some that haven’t been disabled at all and just looped out at the supply lines.

 

[ronn07]

I’d have a look at the oil tank level perhaps. Likely make sure it’s been properly disabled too. Some guys stop it from alarming, by just leaving oil in the tank. Even seen some that haven’t been disabled at all and just looped out at the supply lines.

The oil tank has been removed from the motor permanently.

I mix the oil and gas in the gas tank. The motor has never had the oil tank as long as I have had it.

 

[99yam40]

The oil tank has been removed from the motor permanently.

I mix the oil and gas in the gas tank. The motor has never had the oil tank as long as I have had it.

But do you know how it was disabled?
and how they stopped the oil alarm from sounding?

Only things I know of that will cause that alarm is low oil level and overheat

 

[ronn07]

But do you know how it was disabled?
and how they stopped the oil alarm from sounding?

Only things I know of that will cause that alarm is low oil level and overheat

I don't. As I mentioned. I ran this boat several times last year and the alarm never set off.

I will look for the oil alarm but I am positive it has been removed.

Maybe it was over heating but when up to speed it was sucking enough water to keep it cool. Either way, i am changing the impeller this weekend.

 

[99yam40]

you need to find out how it was disabled, so you can find out what is causing the alarm

something is grounding a wire

 

[boscoe99]

If the oil alarm was removed then so too would have been the over temperature alarm. They are one and the same. A buzzer.

 

[ronn07]

Well, I am pretty sure it's the impeller........
motor was not getting enough water when idling.

 

[racerone]

Still lots of folks ( and new owners ) who are not aware that an outboard needs a new impeller about every 3 years.

 

[99yam40]

Well, I am pretty sure it's the impeller........
motor was not getting enough water when idling. View attachment 378008

now you get to figure out where that piece of impellor went to.
and hope it is not plugging up a passage in the cooling system.
hope just replacing the water pump fixes your problem.

 

[ronn07]

now you get to figure out where that piece of impellor went to.
and hope it is not plugging up a passage in the cooling system.
hope just replacing the water pump fixes your problem.

Found all the pieces. The broken off fin was still attached but broke off in my hand.