Hey guys looking for some opinions. I have a 31 fountain twin 250 efi's. Last time out I got a low oil alarm, we were only a mile from the ramp so I came in on one engine. To settle my wifes nerves when we were putting the cover on I dumped a gallon down that side. lol. So we need fuel next time out and that's when I usually top off oil tanks. So I top off the side I didn't pour the gallon into and it takes 1 1/2 gallons and the side I had dumped the gallon in only takes 1/2 gallon. So I pop the crowling off and the motor tank is down just enough to set the alarm off, float switch moves free, top it off, no alarm. Going to trace hoses for kinks next. I have read on here about some hull tanks have filters, but not seeing them on merc's parts diagram. I have also read some guys pull there tanks to clean them?. Could there be enough sludge in them to plug the pick up tube?. boat is a 1999 with 850 hours of fresh water use. Talked to a couple mechanics and one said to check caps on tanks for tightness and another said that he has seen this happen once in a while. fill it and run it. I'm a life long boater but these are the first set of O/B's ive had so its a learning curve for me. I was also told these draw oil thru crank case pressure?. Any suggestions would be helpful.. thanks tom.