Oil reservoir problems

[truckerjon]

we have a 2005 DFi optimax 225hp mercury outboard. After 15-20 minutes the oil reservoir runs low setting off the low oil alarm. The oil tank (3 gallon) is full. Pressure tested the entire oil system to 10 PSI from the line coming from the check valve on the engine. NO leaks of any type. Engine runs smooth no misses. Have not run an actual pressure test while running yet. Any help or suggestions?

 

[flyingscott]

I am assuming there are 2 tanks one under the hood and one in the boat. If the the one under the hood is running low there should be a lift pump on the bigger tank to fill the smaller tank. I would look at that could be as simple as a switch not working.

 

[truckerjon]

Yes, there is two tanks, The one on the motor is the one that continues lowers and gets air into it and set off the low oil alarm. As I mentioned in original post the lower tank supplies the oil to the engine tank via a pressurized system. No pump is involved in the transfer. thanks for the suggestion. John