Rereading this thread.... Tell us about the known fuel quality, and are you using the carburetor and fuel pump, or still just pouring gas in?? If the fuel is good supply, and it's fed by the fuel pump from the tank, and you know its good fresh gasoline, then have you tried pedal to the floor and crank for another twenty seconds after you think its flooded? Any different result? If you are pouring gas in, its always going to flood very quickly. It does seem by the descriptions given that you may be jumping time, or just really crappy gas. Also, if you don't think its been apart in a very long while, I'd just pull the front apart and have a look at that timing chain......wont take long at all.