Probably a dumb question but .....,<br /><br />I want to change the oil in my OMC 4.3 (1987), and realize it's not as simple as changing in my car. I can't seem to find the drain plug, but is that the ticket. But then doesn't that leave a mess in the bilge?<br /><br />Or should i buy one of those dipstick pumps, but doesn't that leave the sludge/heavy stuff forever in the bottom of the pan?<br /><br />Please advise as to best technique - thanks