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 (OT) and a bottom dead centre (UT) 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 (ZZP), 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 (N) 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 (N) 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 (OT) and a bottom dead centre (UT) 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 (ZZP), 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 (N) 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 (N) 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. <EOS>