I have a 6hp Tohatsu 2006 and went for my yearly change in gear oil on the lower unit. Change went find drained the black stuff and added the new oil. I tightened the 2 screws back and came back a day later and see a spot of oil underneath the motor. I whipped the excess leaking and re-tightened the screws. Still leaking. I went and used it on a trip yesterday and everything went fine..motor ran better if anything even thought it had a small leak all day. Now it is still slowly dripping a now cream color gear oil since i ran it through the motor all day. My dad said it might need to have a "gasket replaced" ? gaskets on the screws? is that so?