one more F-20 mag question

You need to remove No1 plug near the radiator and have someone handcrank it over slowly until you feel compression against your thumb, then stop
the cranking and look for that chalk mark. Once you locate the chalk mark keep cranking the engine until the chalk mark is aligned with the pointer. You could use a big handle screwdriver after you feel compression by placing it in the
plug hole and watch very closely until the screwdriver stops rising. You don't want to drop
that into the cylinder. This is TDC for No1 piston. Your timing marks should be aligned too. Crank the engine very slow after you feel compression. Don't move the engine now.

Rotate the rotor on the mag to the No1 position on the cap and install on the tractor. The rotor should point to No1 in the cap, if not you need to pull the mag and reinstall until it is at No1. Don't forget to remove the screwdriver. Reinstall plug and see if the engine will start.
Hal