Let's start best with what we already know, the classic engine design with two four-stroke cylinders, four valves, the alternator at the right side of the crankshaft, freewheel drive to the starter, the clutch on the left of the primary shaft. Insofar there seem to be no news. Even from the chain to the two camshafts a small part can be seen.

However, the crankshaft has four instead of three main bearings. In the middle there is a connecting rod downwards. Looking at the next picture you could get the idea that it could be part of another cylinder, but it is about intelligent mass balance for the two synchronously moving pistons. And a further piston/cylinder unit would require too much space and friction.

The next picture shows a big rocker arm. It represents the weight of the two pistons, taking into account its and their connecting rods. That prevents primary mass forces. The secondary mass forces are deminished by 70 percent, better than rotating balancing shafts do. For less friction the rocker arm is fitted with roller bearings.

The rest is quickly told, or to be read in the data above. There is still the adjustment of the valve clearance, the need for which is determined by the engine management by comparison with stored load data. The torque is transfered to the rear wheel by tooth belt (image) noise and lubricant saving. The only disadvantage is its appearance. 04/16