Thanks for all the suggestions so far. I see I have a couple of things to try. I know it spins up fine with the plugs out using the starter. I haven't tried to spin it by hand with the plugs out after it is warm. That would be an easy test.
As far as trying another starter, that is a bit more problematic. I need to find one that will fit the ring gear and starter gear that I have in this one. I am not sure if it is the 62 match or the 52 match. I converted the engine from 12 volts to run on 6 volts...coil, starter, and I think ring gear but this was quite a ways back. I know the starter gear and ring gear match... there is no binding or grinding and it releases freely when you release the foot switch.
Checking the bearing/journal tolerances is more whee I am afraid I am headed.
By the way, I have checked for evidence of water in the cylinders and my plugs are consistently sooty black but not wet, oily or flooded. Just a dry black soot. I clean them after about every third start to help it start. I have a spark plug cleaner that runs on compressed air and grit from Harbor Freight.
I am off to give a few things a try from the suggestions above. I'll let you know what I find. Keep the ideas coming. I really appreciate the help.
