85 Merc 150 XR2 oil alarm after first starting
(Davenport , FL)
Turn the key on, alarm chirps as it should. Recently though, after starting, the beep beep oil alarm continues. Checked both oil tanks, and the remote tank is getting lower with use, so I believe that the pump is working. The tank on the engine is full. Also, the motor seems seems to be smoking the usual amount. After idling out into the cove for 5 minutes, then shutting the motor off and fishing with the trolling motor for 15-20 minutes, the next start of the big motor goes just as it should. Quick start, no alarm.
If a check valve was letting pressure off overnite, why would that set off the alarm system, which is either low oil in the on engine tank, or , non rotation of oil pump?
What else to try. I know there is a $200 alarm module on the motor, but I don't know why the condition would self correct after a few minutes, if the module was faulty.
Any other ideas?