The 2cc Dyno sits waiting for me to machine a new contra piston for it. The original contra was, let's say, not as pretty as most of the other parts. When attempting to run the engine, it leaked so bad that any fuel present was pushed up past the contra and out via the adjusting screw threads (actually blown out!). Needless to say, It has not run yet. A simple fix, however, and I still have hopes of success with this rare and special piece.