How to restore the spark Suffolk punch 43 Mower?

can anyone help, I have a qualcast43s lawn mower that has lost its spark. I have had the flywheel off, and everything in there appears to be ok. However I notice that ignition points are not fitted, so what type of ignition system is it. There is just a single coil a witha high tension lead to the spark ,plug, and a magnetized section on the interior of the flywheel. How does one set the ignition timing?. on a Qualcast suffolk punch 43s