This video will show you what causes this problem and how it can easily be corrected.
Mercury oil tank sensor.
Low oil sending unit stuck on creating alarm from control panel.
I also came through same kind of problem few days ago.
There are many complaints by the users of mercury motors.
The oil level is full and you replaced the oil level switch but the problem will not go away.
If you have a steady alarm going off but the oil is not low it is most likely the oil sending unit.
The engine 2 stroke oil tank has a low oil sensor in the bottom of it and can t be replaced without replacing the whole tank.
So your mercury outboard is experiencing the common problem of the alarm beeping 4 times every 2 minutes.
Mercury oil tank vent cap mercury mariner 50hp 60hp 75hp 90hp outboard 19299a1 14 99 new mercury marine mercruiser oil tank switch sensor 87 856156t04 87 856156a4.