Re: Totally stumped. Next stop is a real mechanic
Just to put this thread to rest, I did finally end up taking it to a mechanic. I was having such a hard time just keeping the motor running long enough to attempt an adjustment, and such a limited amount of time ( I can only work on my motor after work, and no later than about 7:30 b/c I have neighbors with small kids) that I figured it would take me a week to get the motor running right. The mechanic charged me $200 and he verified my work on the ignition conversion, removed and inspected the carburetors (clean), re-installed and verified operation, set the idle speed and mixture, set the idle timing, cleaned and verified gap on the plugs, and verified the choke settings. He did discover that my console Tach is about 300 RPM fast as compared to his shop tach, so that was another good take-away. Given that when I had it running right my original problem was I needed to crank down the idle speed to set the timing correctly, this whole expense could've been avoided if I had used the proper tool in the first place (a reliable test tachometer instead of the optical tachometer)
In any case, the mercruiser is now purring like a kitten. No shake, no fouling. The mechanic did comment on the engine and how it is in excellent overall shape. he told me he had worked on the same motor of much more recent vintage and that those are nowhere near in as good condition as my motor is.
Next stop is the lake. Lanier hit full pool yesterday, so its going to be a spectacular boating season (hopefully)
Rgds
