Hi Ante! I removed the old battery ignition system and put the flywheel magneto cdi ignition. This data I picked up from www.aet.si: Flywheel magneto: 4-pole, rotor diameter 103mm Triggering: internal, 2 sparks per revolution Spark type: AC arc discharge Ignition electronic: C.D.I. Maybe I have to calc, Hz = 2 * revs 8)