The thickness of a standard business card is the correct clearance, I forget how many thousandths it is. Easy to bend around the flywheel, and they slide right out with a small rotation of the flywheel once its adjusted.
And, when you set the module location, be sure to account for any radial flywheel runout. I.e. radial bearing play.
Meaning, before tightening the screws, push the flywheel towards the module. While holding it there, do the business-card thing. Can help avoid high-speed collisions. :msp_smile:
we were taught in gr. 8 shop on briggs' .008 air gap... the biz card method often mentioned here on as has given nice fat blue spark on my "points" saws.