Gentlemen, I just bought a 1980 7 1/2 Johnson. Have been playing with it on the river and then in the barrel at home. It starts easy, (about 3 revolutions), idles great. Runs at full RPM great but has a dead spot right about where the carburator cam follower engages the advance plate. Wants to surge or gag down. When I pull out the choke it seems to get over that 'dead spot' and then goes on up to a higher RPM. Thinking it might be a hose problem I put another hose with new OMC fittings and no change. I backed out one spark plug at a time and did a compression check and they are both running about 95psi. This little motor has CD ignition, and like I said, it runs at idle and top RPM good. So I'm comfused for the moment. Hope some of you guys might have some insight here. How critical is that carburator adjustment on the cam follower. I've got a carb kit ordered. Also, was the 80s model 7 1/2 just a OMC 6hp with a bigger carb? I owned a 6 Evinrude years ago but cant remember what it looked like in comparison with this newer 7 1/2. Was the 80s model 7 1/2 a total re- design? All input appreciated. River Boy.
