o go back to the beginnings, the model had its origins in the brand new 594cc engine (officially designated M268/1) that made its public debut as the R68 model at the 1951 IFMA Motorcycle Show in Frankfurt. With 35hp on tap, BMW stated the R68 would be good for a genuine 100mph, and it was. Virtually square at 72mm x 73mm bore and stroke, with a compression ratio of 6.3:1, the engine would rev to 7,000 rpm. A Norris magneto supplied the sparks, and the engine breathed through a Bing 24 carburettor. A gear oil pump was located in the engine sump, feeding oil along the crankshaft and to the top end, whence it drained back into the sump. A single plate clutch, spline-coupled to the gearbox input shaft, separated the power unit from the shaft final drive. Current came from a six-volt 60-watt generator. The cylinder head was secured by two cap screws in addition to the four studs that bolted through to the crankcase, with spherical ball races supporting the built-up steel crankshaft. The rocker arms
