Posted by msteinkampf on 11/29/22 - 1:43 AM
#10
I had this same problem with my 1990 Mercury 90 HP outboard. My oil tank under the engine cowl has a sensor that detects when the oil level is low. If that sensor malfunctions, you get the intermittent beeping despite plenty of oil in the tank. Look for a wire that originates at the bottom of the tank. If the beeping stops when you disconnect the wire, you have confirmed it’s a bad sensor.
As I recall, the sensor is a float that contains a magnet, and it’s not accessible to maintenance. The problem resolved when I replaced the oil tank.
Michael