If it was points, I would say to check if they were out of adjustment and not opening. The way IDI (points, automotive) work is the coil is saturated and spark occurs when power is removed. With a CDI ignition, the coil is lower impedance and will charge quicker. The spark occurs on the charge instead of the discharge. Maybe it is just not charging up the coil fast enough to cause spark. That leaves the charge in the coil. With a couple of cranks, it charges enough to spark on the discharge when you pull the wire.