I have a D1 plunger that has a D10 175cc engine fitted (bought as a rolling chassis). I have dismantled the engine and found a flat top piston with 30 6/65L 90-1461 BSA stamped on the crown. It seem to have good compression although came out with only one ring fitted but has three grooves. I intend to use the same engine and the piston is in good shape so need to find where I can get a set of rings. I'm in Central UK and any help would be appreciated.
