Setting the Ignition Timing
Key slots and keys (wedges) are used in series production by the manufacturers in order to enable precise setting of the ignition timing.
A graduated disc or a dead centre measuring device (special tool) is used to set the ignition timing in order to measure the position of the piston before top dead centre (TDC). You can set the ignition timing to the engine by aligning the marks on the rotor and the stator in conjunction with measuring the piston position before top dead centre. If the stator is located approximately in the centre of the available setting range (slots on the stator plate), tighten the stator fixing screws by touch so that it does not move by itself but can still be rotated manually. Turn the crankshaft slowly in the direction of rotation until the piston has reached the required position before TDC (e.g. 1.6 mm).
The following applies with rotors with grooves:
The following applies with rotors without grooves:
If the mark on the stator is covered exactly by the mark on the rotor, the ignition timing is set correctly. Check the ignition timing.
Position the piston again in the required position before TDC and check that the marks on the rotor/stator still correspond. If not, simply loosen the stator fixing screws and push the stator so that the marks correspond, tighten the stator screws again correctly.
If the marks cannot be aligned with correct TDC position of the piston, it is mostly due to incorrect rotor position (with rotors without grooves) and the rotor must be removed from the lateral journal using the PVL extractor tool. The setting procedure must be repeated.
It is helpful to put marks on the casing and rotor with a permanent felt tip pen.