This simple tool makes it possible to accurately adjust the advance, excluding all inaccurate readings, which is a problem that even the most expert instructors run into. To use the key, it is sufficient to insert the projections - found on the lower face - into the flywheel fixing holes in the rotor of the new inner rotor ignitions. These holes are free because during the advance regulation phase, the flywheel hasn’t yet been installed. Once the rotor and key have been joined, the flywheel can be moved by rotating the tool until the regulation hole is aligned with the right-hand fixing hole of the stator. To make the alignment, insert a pin or drill bit with 5 mm diameter.

With the rotor and stator perfectly aligned, to set the advance with absolute certainty all you need to do is shift the stator, rotating it thanks to the regulation guides, making the measured piston position coincide with the comparator.