Well THERE'S your problem!

[slipperymongoose]

Wow you can see the bronze coming through in those bearings.

[twinrat]

Your piston does not show excess heat  after all the hours that have been put on it since new,though your piston pin does show over heating .and colouring ,you need to have your pin apush fit by hand when cold and able to be pushed through piston and small end eye at same time.A piston in good running condition normaly
has a black carbon burn mark underneath  that is with non detergent type oils from my experance..

[twinrat]

Hi burning 1,, this is a book that should grace you book shelf .TUNING  for SPEED   BY PHIL IRVING  First copy written 1948 but since updated . this is extremly valuable knowledge if you are racing these older design of air cooled motors and can be applied to water cooled to.

[burning1]

Hi burning 1,, this is a book that should grace you book shelf .TUNING  for SPEED   BY PHIL IRVING  First copy written 1948 but since updated . this is extremly valuable knowledge if you are racing these older design of air cooled motors and can be applied to water cooled to.

Thanks so much for the book reference. I was hoping to find a good book on building air cooled motors, but I didn't know where to look.