IGNITION DEVICE OF MULTI-CYLINDER ENGINE

PURPOSE:To eliminate smoking of an ignition plug in a multi-cylinder engine having a phase difference, by firing the spark plug simultaneously in a specific range of operation and alternately in the other range than the above. CONSTITUTION:Since the regular ignition timing and ignition advance angle of the second cylinder 2 are small in a range of low speed operation, terminals TL1 and TLB3 are arc connected by a rotor conductor 9a similarly terminals TL2 and TLA3 are connected by a conductor 9b of a distributor, and a spark plug L2 of the second cylinder 2 and a spark plug L1 of the first cylinder 1 are simultaneously fired. On the contrary, since a rotor 9 is in an advanced position at the regular ignition timing of the second cylinder 2 in a range of high speed operation, the terminals TL2 and TLA3 are connected by the conductor 9b, but the conductor 9a causes an arc also with an earth terminal TE, then the first cylnder 1 is not fired. Accordingly, smoking of the plug can be eliminated by avoiding useless ignition.