earlwb

I don't know if there is enough material left in the piston to cut a couple of grooves for a small wrist pin retainer ring or not. But one could do that to keep the wrist pin from moving. It isn't easy to do it though. But when you rotate the cylinder, you'll need to ensure the ports match up with the piston OK and that the piston skirt doesn't hit the backplate or crankshaft either. Oh yeah, some companies actually drilled a small hole in the piston and wrist pin and pressed in a small roll pin too. One could also cut a groove on one side of the roll pin just on the inside edge of the piston and put on a wire retaining ring there too, I remember seeing that on some old vintage engines before. I have even thought about just using some J&B weld epoxy to lock in the wrist pin too. The cylinder and piston isn't all that expensive to try that on either.