1. Remove plug (drawing on the left), located on the clutch housing so that the alignment marks are visible (indicated by the arrow in the figure on the right) on the flywheel and a plate screwed to the crankcase.
2. Start the engine, warm up to operating temperature, then turn it off.
3. Remove the vacuum hose from the ignition distributor and close it with a plug.
4. Connect the stroboscope according to the instructions.
5. Start the engine at idle and point the strobe at the marks. The flywheel alignment mark must align with the mark on the plate, which indicates the degrees of displacement of the ignition angle setting from top dead center (TDC).
6. If adjustment is necessary, loosen the ignition distributor mounting nuts and slowly turn it until the corresponding marks are aligned.
7. After aligning the marks, tighten the distributor mounting nuts and re-check the ignition timing.
8. Increase the engine speed and make sure that the marks begin to move in the direction of a larger increase in the ignition timing. This indicates that the centrifugal ignition timing controller is operating.
9. Install the vacuum hose in place and check the ignition timing at increased engine speeds. In this case, the labels should shift even more. This indicates that the vacuum ignition timing controller is working.