Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

No piston packing
Try some graphite string around one or two grooves

Dennis, I just rang MSM and double checked with the owner John and he stated that they don't use any packing on the pistons on the Pevensey or Echuca type models.
Still mucking around with it now, I think I got the position right for TDC and BDC with it just cracking at each end. Still mucking around with the ecentric timing which I have to say is a bit of a PITA.