Kind of a tough question to answer because the Duty Cycle is based on a number of variables.
Basically the standard stop/starts per hour recommended for the M267 are 6-10.
To calculate a more specific Duty cycle you would need to know the fixture count & GPM�s feeding into the basin, the basin capacity along with the collected volume capacity within the basin, also the discharge length and head, taking into account peak Vs. non-peak usage (yes it gets complicated).
There are mathematical equations to figure out a close Duty Cycle predicated on the info I just listed above however, depending on peak, non-peak or moderate demand the Duty Cycle will fluctuate.