BMW developed with Rotax a 798 cc (48.7 cu in) parallel-twin engine with a 360 degree firing order.

To counter the significant inertia produced by the pistons reciprocating, BMW devised a third vestigial connecting rod to a balance weight.

The engine was oiled by a dry sump system, and a soft ignition-cut rev limiter engaged at 9,000 rpm.

BMW tuned the F800 series engine to run lean, typically with air-fuel ratios in the range of 15:1 to 16:1.

The F800S was discontinued across most of the world after the summer of 2010 with only a few Central American and Eastern European countries still stocking the last supplies of the model.