recently purchased this boat with a 150 mercury outboard. It has a large abt 2 gallon oil tank under rear seat and a small tank on engine. I put a gallon of oil in the tank under the seat. Installed a new cap on the engine tank. have not had the boat out yet and just started it at idle on muffs using a 6 gallon premixed tank. Today I checked oil tank and it has maybe a quart left in it. I noticed oil under cover and found a small line going from small tank to oil pump , I think,it was disconnected. could all the oil siphoned out of the tank under the seat? I found a good amount of oil on ground under engine. Not sure if I should add another gallon and try again now that i reconnected the small line. Any help would be appreciated.