I have a 1989 3.0 merc. that will not start, will not hit a lick. I put a new starter and before I put it on it started and one day out on the lake the starter went out, when I put the new one on it turns over strong but will not fire, I have put new plugs in it the first of summer. I am getting gas in the carb, but dont know where to start??? Any help???? Thanks alot