As said previously, the engine kicked back and broke the fitters wrist, we believe that this was down to a broken impulse spring in the magneto. We didn't fancy that happening to us so we plan to fit a starter. The first job was to source a starter ring, which proved to be harder than first anticipated; eventually I found one in Germany that fits a Mercedes Unimog. The flywheel needed to be machined to take the ring, it was close needing 1.5mm removing off diameter. It wouldn't fit my lathe so Danny at York Machining Sevices did it for me. We heated the ring gear and dropped it in place and let it cool. The next job is to make an adaptor plate to hold a starter motor, more on that soon.