Following a recent post by Sunshine man, I cut a piece of copper gauze to roughly the shape and size of a cigarette paper. This was rolled into a cylinder, shaped to fit in the transfer port and fitted fom the bottom, having previously removed the cylinder. I made it a tight fit and used a flat punch to drift it to just below the inlet. If there is a need for it to be removed, it could be turned ninety degrees and withdrawn with a wire hook. The cylinder was then re-fitted and I am yet to test the modification. On a related subject, these small Sunshines must have been assembled by dwarfs as there is only one hand hole in the crankcase and not enough space to access the con-rod bolts. The only method I can see to fit the rod and piston is to prepare the big end cap and shims, complete with bolts stuck with heavy grease and offer it to the crank at 12 o'clock, then lower the rod onto it, taking care not to dislodge the bolts in the process. Nothing like the 7hp which has two decent sized hand holes and plenty of space to tighten the nuts.
I hope I have made some progress,
Austral. '