1997 mercury 125 low oil warning alarm

[Kevin J Schmitz]

The low oil alarm came on on my 1997 125 hp outboard last Sunday . I shut the motor down and checked it and it was 3/4 full . I went ahead and topped it off . I turned the key to the on position and the alarm was still sounding . I went ahead and started the motor and it was still sounding . What might be causing this ? What should I look for ? Thanks for any help anyone can give . Kevin

 

[Iceman66]

When turning the ignition key to on ,you should have a short beeeeeep-beep-beep and then silence.
This confirm that your warning circuit is ok.

My guess is that your oil warning module is defect,they often corrode inside and causing the alarm to sound when it should not and the other way around,
but follow all the wires(except black) from module and check that they dont hit ground anywhere .

Also check the wires/connections from low oil sensor in oil tank not hitting ground , and check out the sensor as well.

I recommend you remove all the oil injection parts, buy a block of kit fore the oil pump driven axle,and premix oil,
will save you a lot of worrying about this: " does it get oil now or not issue"

 

[joed]

Not sure what oil tank that motor has. Some of the tanks have a float inside that has a magnet glued to the bottom of it. As the float goes up the magnet goes up and the switch opens for low oil. The magnets have a tendency to fall off the float. Then they lay at the bottom and trigger low oil. This can be confirmed by simply turning the oil tank upside down and see if the alarm goes. Also if you remove one of the blue wires from the tank and it stops then that is likely your issue. there is no repair. You need to replace the whole tank.

 

[Kevin J Schmitz]

Thanks guys

 

[Texasmark]

Your first clue was that it remained on without the engine running and you saw that the tank was 3/4 full. Doubt seriously if the flow was effected so I wouldn't worry about that. If you are short on funds or don't feel like tearing into it, pull one of the 2 blue/white striped wires out of it's socket in the engine and the alarm should go off. However you need to keep tabs on your oil level. No big deal, I used to check mine every time I came home and if I were to be on a long trip I would check it during the trip.

Mark

 

[Kevin J Schmitz]

I checked everything on the water that I could and I figured it wasn't nothing to bad . It was just a pain when your on the water and miles from the ramp . I'm going to take every ones advice and check into it further this weekend . Thanks again

 

[themish]

Did you ever resolve this issue? I have something similar going on.

 

[mercinfl]

My 1995 115hp inline 4 cyl 2 stroke Merc outboard with the oil tank under the cowling had this problem, the magnet came unglued. I was able to remove the tank and the magnet from inside the tank. With a coat hangar shaped just right I was able to remove the clip that holds the float. I then cleaned up both and think I used JB weld to secure the magnet to the bottom of the float. I then slid the float back down a coat hangar with the clip (looks like a push on type similar to an internal tooth lock washer) when it was resting on top of the plastic shaft the float slides up and down on I carefully used a dowel that I jammed a socket of the correct size on the end and pushed it down to lock the float in. It took patience and several tries but that was 3-4 years ago and it still works correctly. It's pretty tricky cause its about 18" down in the bottom of the oil tank from the fill opening.