Some flywheel mags have a certain amout of spark advance. Put a timimg light on one and you will see. You will find data on one of the small engine web-sites also explaing that. I will look for it again. ALSO the flywheel has a purpose....to absorb and smooth out power impulses. In my opinion.....I think if you remove a flywheel and go with a fixed ignition....the engine will run NOT as smooth as with flywheel. Good food for thought!!!! Capt,n[8D]