37 d magneto swap

Timing them is easier than the Edison as they provide a spark at each impulse. Remove your spark plugs, connect them to the magneto, and lay the plugs on the tractor to provide a ground, but away from the hole you removed them from so a spark doesn't ignite the air-fuel mixture which can be ejected from the plug hole. Turn the flywheel until the flywheel side is coming up on compression (you'll feel a pressure on your thumb if you hold it over the plug hole), then turn until the LH IMPULSE mark on the flywheel lines up with the mark on the transmission case. Around that time the magneto will impulse and provide a spark to a plug - put the plugs back in and connect the wire to the plug which sparked to the flywheel side (and the other wire to the plug on the pulley side), and you should be ready to go (or do a more accurate timing with a timing light - the archives have a lot of info telling how to do that).