ok i just traded a shotgun and 200bucks for a 1975 sidewinder with a 1967 merc 1100 ss outboard. I took off the lower unit and checked the impeller and it seemed OK, although the first time ive ever seen one.I blew comp air through water tube and the telltale is peeing but I can pee harder myself, and the water is pretty hot coming out. there is water coming out the prop too, but what about the two little rectangular ports right next to each other on the back? should water be coming out there also? had the boat out this morning and it really hauls but i dont want to mess it up. can someone give me the lowdown on this motor-oil mix ratio-cooling system-common problems-etc.