Ignition circuit for a combustion engine, having a spark plug which is arranged in a combustion chamber of the combustion engine, • wherein the combustion chamber is delimited by a piston which is moved to and fro between a top dead centre and a bottom dead centre and, via a connecting rod, drives a crankshaft, • and having an intake channel with a control element for apportioning combustion air for an idling situation and an acceleration situation of the combustion engine, • and having an electronic control circuit, which is designed to trigger an ignition spark at the spark plug at an ignition time, as a function of a crankshaft angle (°KW) of the crankshaft, • wherein the control circuit is provided with at least one ignition time (ZZP L) for the idling situation and at least one ignition time (ZZP B) for the acceleration situation, • and the control circuit is designed, in the idling situation, to set the specified ignition time (ZZP L) for the idling situation, characterized • in that the control circuit is designed, in the idling situation of the combustion engine, to monitor the course of a rotational speed of the crankshaft over at least one specified crankshaft angle range, • wherein the compression stroke of the combustion engine at least partially lies in the specified crankshaft angle range, • and, in the idling situation, to detect a drop (Δn), occurring within the specified crankshaft angle range, in the rotational speed of the crankshaft as a value, • and is designed to compare the value of the detected drop in rotational speed (Δn) with a specified value of a drop in rotational speed (Δn G), • and, when the specified value (Δn G) of the drop in rotational speed (Δn) is exceeded, to change over to the ignition time (ZZP B) for the acceleration situation. • wherein the combustion chamber is delimited by a piston which is moved to and fro between a top dead centre and a bottom dead centre and, via a connecting rod, drives a crankshaft, • and having an intake channel with a control element for apportioning combustion air for an idling situation and an acceleration situation of the combustion engine, • and having an electronic control circuit, which is designed to trigger an ignition spark at the spark plug at an ignition time, as a function of a crankshaft angle (°KW) of the crankshaft, • wherein the control circuit is provided with at least one ignition time (ZZP L) for the idling situation and at least one ignition time (ZZP B) for the acceleration situation, • and the control circuit is designed, in the idling situation, to set the specified ignition time (ZZP L) for the idling situation, characterized • in that the control circuit is designed, in the idling situation of the combustion engine, to monitor the course of a rotational speed of the crankshaft over at least one specified crankshaft angle range, • wherein the compression stroke of the combustion engine at least partially lies in the specified crankshaft angle range, • and, in the idling situation, to detect a drop (Δn), occurring within the specified crankshaft angle range, in the rotational speed of the crankshaft as a value, • and is designed to compare the value of the detected drop in rotational speed (Δn) with a specified value of a drop in rotational speed (Δn G), • and, when the specified value (Δn G) of the drop in rotational speed (Δn) is exceeded, to change over to the ignition time (ZZP B) for the acceleration situation.