3. Balancing the single-cylinder engine

The rotating and reciprocating masses of the single-cylinder engine are the source of bouncing and shaking vibrations (figure  2 ).

The amplitude of these vibrations may be limited by carrying out a suitable balancing. The latter is not always possible, and when it is, it is rarely easy to implement.

In this paragraph, we give basic elements relative to the balancing of the single-cylinder engine. These notions will be useful, by adapting them, for the study of multi-cylinder engines.