Good grief the world is a small place. That's a CH conversion from Wyoming USA.
The mechanical timing can be adjust to perfection with a little thought. It was called TCSA, Throttle Coupled Spark Advance
Anyway idle timing should be in the 3-5 degrees BDTC range and WOT it should be in the 28-30 deg BDTC range. You can adjust the static timing by making the pushrod longer or shorter. OR by loosening the front ring with the magnet and twisting it.
The TOTAL timing movement depends on the length of the arm on the carb. So by making the arm longer you increase the range of timing (example 2-32 d BDTC) shorter and decrease the range (5-28 d BTDC).
You can also adjust the timing to have a curve by changing the angle between the throttle butterfly and the pivot arm, There be less movement of timing as the arm and push rod become closer in alignment.
Good luck
TKG
Last edited by tkg; 12-11-2013 at 10:06 AM.