Is an ignition advance angle of 12 degrees or 9 degrees better?

[VanIsabelle]

An ignition advance angle of 9 degrees is better, for the following reasons: 1. Ignition advance angle range: The ignition advance angle is generally between 6 degrees and 12 degrees. A 12-degree ignition advance angle is too large compared to 9 degrees, which can result in delayed ignition. 2. Disadvantages of delayed ignition: If ignition is too late, the gas will have difficulty performing work, leading to increased fuel consumption, reduced efficiency, and louder exhaust noise, all of which affect the engine's working efficiency. Additional information: 1. Ignition advance refers to the spark plug firing before the engine piston reaches the top dead center of compression. 2. The angle through which the crankshaft rotates from the moment the spark plug fires until the piston reaches the top dead center of compression is called the ignition advance angle.