Ok. I'm new to outboards. I bought an old '71 Merc 650 on the cheap and went to change the lube in the lower and only got about half a quart out. Yes, it was milky. I don't have a pump to refill it yet, but shouldn't I be getting more out? I've done all kinds of searches and can't seem to locate a set of seals. So...if I don't want to put a lot into this motor, can I just keep topping off the oil each month and make sure to replace it each year?