Those are very nice bikes , Jim . I'm a bit jealous .
Concerning my bike , it would start after I put the bike together about 4 years ago and would only run for about 10 minutes . After trying what seemed like everything , it wouldn't even do that . It wouldn't start prior to Wayne's bore job , but did immediately after , for about 15 or twenty minutes . Then the motor seized . I cleaned the piston and bore after that and every time since . It is now due for another piston . I believe that I have addressed every possible air leak , so hopefully a new piston and rings will be the last 'step' .
Mine seems to be a 'special' case , as everyone else , other than maybe you , hasn't had the same problem(s) .
Pete .