US Patent 7263971 Knocking control device for watercraft engine

A knocking control device for a watercraft engine includes a knocking learning value renewing section for changing a knocking learning value toward a low octane number ignition timing map when the knock sensor detects a knocking condition. The device changes the knocking learning value toward a high octane number ignition timing map when the knock sensor does not detect a knocking condition. An ignition timing determining section retards or advances an ignition timing based upon the knocking learning value given from the knocking learning value renewing section. The knocking learning value renewing section is constructed not to change the knocking learning value toward the high octane number ignition timing map, when an engine speed is in the vicinity of a full throttle condition.