i have a 1974, merc.1150. and i just noticed that there is oil leaking out behind the prop. while the motor sits with tilt all the way down and motor straight. i pulled off the prop, and i found fishing line, and oil around the seal. the seal looks good ??? so then i drained the oil, and it was a primer gray color. now what do i do ? im new a this, and i want to learn to do it myself. the prop is off, the inner big circle part is off(the one with all the teeth on it that i used a hammer and driver to unscrew)but now,if the seal is bad, it seem like i need some sort of pully to get the seal out ? how do i really now if the seal is bad, and how do i get oil back in it ? what type ? thanks. 