No, the coil number would not change. The Kawasaki coil should show 21121-2085 on it. Does it?
If you disconnect the ground wire and there is still no spark then it can only be a failed coil or the magnetism of the magnet on the flywheel is too weak or the air gap is too large. The air gap is .012”, cold. A business card is not the proper way to set air gap. It can work, but business cards come in different thicknesses. If the thickness is within spec, your fine. I think a standard card is .014”. Engine starts fine cold. But when everything warms up and expands, you may be getting more clearance. (A hot engine actually gets hotter for a period once you shut it down) See if you can tighten the air gap, use an actual feeler gauge if possible. Then retest.