Phase Difference of Dual Point Distributor

Disconnect wire from retard side of distributor. With engine idling, adjust timing to 15° BTDC at 600 RPM. Reconnect retard side wire and check that timing is now 5° BTDC. If phase difference is not correct, loosen adjuster plate set screws (two) and rotate adjuster plate as required. Ignition is retarded when plate is turned counterclockwise.