Petrol start kerosene run engine: discussions

This is not an automobile engine, and it never can be one, due to the low torque that it produces.

This machine is used to power centrifugal pumps, and earth vibrators, in places where electric power is unavailable, thus making electric motors useless as prime movers. examples of such places are construction sites and cultivating lands.

Now is this engine a two-stroke or a four stroke engine ? does anyone know about its working mechanism in detail ?