classic motorcycle forum

Hi I recently rebuilt a Wisp moped,  worked really well then suddenly it wouldn't start because the magneto didn't turn when pedalled so no spark. The clutch is free and does turn when pedalled. I did replace the clutch shoes and reassembled it all and it did work ok. I removed clutch cover again and re fitted it ensuring plenty of tension on mag cover to ensure that didnt move so I tightened the clutch cover really tight so cannot figure out why magneto and clutch cover do not turn when pedalled - only the clutch turns. Magneto and clutch cover will turn freely by hand. Tightening up the nut should ensure the outer drum is taper locked, and that should transmit the drive but it isn't!  Are there any  Raleigh moped owners out there that can help with this Problem? I would be very appreciative of any help! Regards Bob