The points made regarding the crankshaft pulley timing marks (or lack of the same) are equally appropriate to dynamic timing. If you are unable to establish where the timing mark should be then consult a good workshop manual or preferably have the job attended to professionally. If you take the latter course then the person who carries out the test will make a timing mark on the crankshaft pulley, which you can later make permanent with a centre punch for future reference! Assuming that you can establish the correct timing mark, proceed as follows. Disconnect the vacuum advance pipe from the carburettor. Highlight the timing mark using typists' correction fluid. Disconnect plug lead number one and connect the two leads from the stroboscope to the lead and plug respectively. Start the engine and shine the strobe onto the spinning crankshaft pulley. The stroboscopic light will flash every time number one spark plug fires, and appear to arrest the motion of the crankshaft pulley so that you can easily compare its position relative to the crankcase join t.11 the notch or other timing mark appears to the left of the crankcase joint then switch off the engine and retard the ignition by moving the distributor slightly in the direction of the rotor arms travel, or vice versa.