Pfaff expression 2014 Service Manual page 25

Timing:
If the adjustment is not correct, remove the needle-rise clamp.
Loosen the three screws 29 in the lower flat-toothed-belt sprocket.
Re-fit the needle-rise clamp and repeat the procedure as described in "Check" until the needle bar has
moved upwards by 2 mm and the clamp is in contact with the spacer (fig. 8).
Turn the long drive shaft 28 in sewing direction until it is possible to insert the pin gauge in both holes
(fig. 9).
Insert the pin gauge and tighten one of the screws 29.
Cross-check:
Remove the pin gauge.
Tighten all three screws 29 very firmly.
Check again with the needle-rise gauge and the pin gauge as described under "Check".
23