M14x1.25 adjustment screw for ignition timing on 2-stroke engine (with M14x1.25 thread). This measuring tool is not as precise as a micrometer screw, but with this adjusting screw the vehicle's ignition timing adjustment can be done at least to tenth of a millimetre. This is adequate for most ignition systems. For fine tuning on the race track, we recommend the Buzzetti ignition timing micrometer screw with order number 21745.