Re: Oil issues 87 Yamaha 115etlh
There is an oil pump on the remote oil tank. The one in the boat. That pump transfers oil from the remote tank to the main tank (one on the motor) if and when the brain of the motor tells it to do so.
The sensor that goes into the main oil tank has three switches within it. As the float rises and falls, these switches open or close. When the float drops from the top position the top switch opens. Nothing happens. When the float gets to about the middle position the middle switch closes. This tells the brain that the tanks needs some oil. The brain then turns on the pump. As the pump runs oil transfers to the main tank. As the tank is filled the float rises. When the float rises to the top the top switch will close. This tells the brain that the tank is full and to stop sending oil.
Sounds to me like the pump is not shutting off, in which case it will keep pumping oil which will send oil out the air vent and/or perhaps cause the sensor/cap to be blown off.
I would first verify that the sensor switches are opening and closing as they are supposed to. Yes, the sensor is new but it can't hurt to check it. This will also be a learning tool for you to see how it functions. If the sensor checks OK, I would then check to make sure that the wire leads from the sensor to the motor (oil control unit) are in good condition. That is, they have continuity and are not broken or corroded. Check both the wires that go to the brain (top to bottom they are white, brown and red) and the wire (black) that goes to ground. The system works off of a ground reference. If the ground wire is broken then the sensor cannot tell the brain the situation with respect to the float sensor switches.
Do these checks and then get back to us. I note that you said this should be an easy fix. It might well be. Most fixes are easy. Finding out what in the hell needs fixing can be the tough part.
