Piñón

The sprocket on the crankshaft with part number 1-042 drives the camshaft in the BMW Isetta engine via the timing chain, thereby ensuring proper valve timing. During an engine overhaul, the tooth flanks and seat on the crankshaft should be carefully inspected for wear marks and play, as worn sprockets lead to inaccurate timing and increased noise. For a durable and reliable restoration, it is recommended to replace both the sprocket and the timing chain at the same time.