by Steve J » Sat Mar 12, 2016 11:53 am
I experienced misfiring with an AF light flywheel several years ago - it was providing trigger pulses more than once per revolution of the flywheel. I checked it with a strobe, and discovered that the pulses occurred when the centres of some of the pole pieces in the flywheel passed over the pickup coil. I eventually decided that the brass rivets/plugs holding the pole pieces in place (being non-magnetic) were the cause of the problem, causing a disturbance in the magnetic field as they passed over the trigger coil. I decided to drill out the brass plugs, and drilled & tapped the holes to fit M6 countersunk head retaining steel screws from the outside of the flywheel, trimming the ends of the screws flush with the pole pieces. A long & messy job with lots of magnetic swarf, IIRC...... The result was amazing - only one pulse per revolution & no misfiring. (I don't know if AF flywheels still use the same method of retaining the magnetic pole pieces, but if so, AF need a lesson in basic electromagnetic theory.....)
I imagine that as long as it's only getting one trigger pulse per revolution, the ignition retard unit will work with all types of flywheel. If it's getting several random pulses per revolution as well as the correct one, I would say all bets are off!
Last edited by
Steve J on Sat Mar 12, 2016 7:28 pm, edited 1 time in total.