OK, so the engine runs pretty well now?  If the bottom plug still looks messy, perhaps you need to pull the powerhead and check the lower seal components, not a tough job.  Does the engine still “pop”/falter at mid range when accelerated quickly?  Is the engine getting up to temp?  It won’t idle very well if it is running too cold.

Tom Bertulli wrote:

Thanks. I’ll keep this in mind.

The only other thing I can add is what I ended up doing on my stubborn 69 6hp.  It kind of ran like yours, a little fussy starting, strange idle needle adjustment, and bog/lack of WOT power.  I wasted alot of time looking for problems that were not there.  Finally, upped the high speed fixed jet from .044 to .048″ which solved all the issues.  Don’t know why this was necessary, perhaps just an old/worn carburetor.  There were about three different generations of carburetors used on these engines, so I’m thinking your high speed jet is much bigger.  Have you removed it from the carb?  Soak it in strong carburetor cleaner.

And, I would agree with you, this is not an ignition/timing issue.  The timing light shows that it is set to the advanced side, which is fine and wouldn’t cause the issues you report.  OK, won’t pound this thread into the ground, seems like the engine is running OK now.

Tom I have the red atom’s call me 1 914 310 7086 Dave.

OK, just reread and caught up on your weak ignition issue while cranking.  I can’t remember if you said that you replaced the mag plate?  That is all that can be done along with replacing the brass support and aluminum retainer to address the slop issue.  There is nothing that can be done if the actual aluminum on the crankcase pilot bushing is worn.  This engine was used commercially, so this would explain the excessive wear.

You have replaced the upper seal, so oil leakage into the mag plate is not an issue, correct?  I would just convert the engine back to its original breaker point set up if oil leakage/seapage is not an issue.  Carefully “dimpling” the brass retainer plate usually will usually compensate for most of the slop found on the actual bushing, but it is probably a good idea to replace that round aluminum retainer that the mag plate screws into.  The ignition modules seem to add some complexity to this very basic simple magneto along with some reliability issues.  I’m sure you can find a used mag plate somewhere, I know I have a few.  This way, you can keep the modified mag plate aside without having to pull it all apart, reverting it back to its original wiring form.  The used mag plate can be swapped out relatively quickly.  Needless to say, I have not had any experience with these modules, so don’t have much knowledge, accept what I have read here.