Method for monitoring non-return valves in gas supply lines of a gas motor

The method involves detecting a temperature mechanically or electronically. A signal is activated when a detected temperature in a gas supply line (5) lies outside a predetermined target range. A signal is output with the information, in which the temperature beyond the reference range is determined in the gas supply line or the gas supply line is assigned to a cylinder (10). An independent claim is included for a gas engine with a pre-chamber.