How to Adjust Ignition Timing

[LaCarson]

Ignition timing adjustment method is as follows: 1. Adjust the contact gap of the circuit breaker, because the size of the contact gap not only affects the strength of the high-voltage spark but also influences the ignition timing. When the contact gap is larger, the contacts open as soon as the cam touches them, advancing the ignition timing and shortening the contact closing time, which reduces the primary current and secondary voltage, weakening the spark plug's spark. Conversely, a smaller contact gap delays the ignition timing. 2. Rotate the first cylinder piston to the position where the compression stroke ends and ignition begins (determined by the mark on the flywheel or the control screw on the timing gear cover. The distributor shaft tail has an eccentric protrusion that must correctly engage with the matching recess to reach the ignition timing position). At this point, the distributor cam should just push the contacts open, and the rotor electrode should align with the first cylinder's distributor electrode. 3. Loosen the distributor housing clamp bolt, rotate the distributor housing to close the contacts and eliminate the gap, then turn the housing in the direction of the distributor shaft rotation until the contacts just open, and fix the housing. 4. Install the rotor and distributor cap, inserting the first cylinder's high-voltage wire into the terminal indicated by the rotor. 5. Following the specified ignition order and the distributor shaft rotation direction, insert the remaining high-voltage wires for each cylinder. 6. Start the engine, let the coolant temperature rise to 70-80°C, then suddenly open the carburetor throttle. Smooth acceleration with slight metallic knocking sounds is ideal. If there is no knocking and acceleration is difficult, the ignition is too late. If sudden acceleration causes obvious metallic knocking, the ignition is too early, requiring readjustment. Adjust by rotating the distributor housing or the adjustment nut to retard or advance the ignition timing accordingly.