zebcotia,
It sounds like this is a "working bolt" so it might be more productive to just do a few things first before spending hours on troubleshooting.
If it hasn't been done in quite awhile, a full tune-up, with a valve adjust and timing check would be a start.
The sluggish starter motor on a warm engine is usually a classic for a starter motor rebuild. A current draw test would indicate whether it was the starter or the battery/connections.
The fact that you can boost it and get it spinning like heck and it still won't fire tells you there is more involved than just the starter.
I am not sure on this, but the fuel could be leaking into the engine through the carburetor when warm, instead of back to the tank. This could cause a flooded condition. I have found the fuel level in the little sight glass to be misleading sometimes.
You can pull plugs and read them when this happens...you can do more sleuthing, but you could also just do the tune-up and valve adjust THEN see what happens. Your field of problems would be greatly narrowed by doing this.
Stuart
