20-02-2022, 03:17 PM
Setup:- C35A dynamo- third brush dynamo with brushes on hinged holders, Cut out type CF3, Switch panel type SM5 (As per fig 1 Dave Mann PW A7 Feb 2022)
First time out for a decent run this year. Initially, the dynamo output wobbled about on a 3 - 4 amp charge and after 60 miles or so settled in to a nice steady 8 amp charge at "cruising speed". I assumed that perhaps the commutator cleaned up, brushes settle etc etc. BUT, on occasion, when the revs drop, the ammeter shows about 2 amp discharge and the ignition light does not come on. ALSO, on occasion, when stopping the engine and ignition OFF, the ignition light stayed on !! Cutting the battery supply by the master cut off switch obviously put the ign light off.
Looking inside the CF3 cut out, the spring holding the contacts open looks OK as is the braided wire from the moving contact to the solenoid coil. I am reluctant to aggressively clean the contacts inside the cutout, and normally clean them by 'sanding' with a piece of clean card slid in and out a few times, then clean with alcohol.
My prognosis is that the spring inside the CF3 has become too weak to pull the contacts apart and needs to be shortened ??
What do the experts say ??
Bob
First time out for a decent run this year. Initially, the dynamo output wobbled about on a 3 - 4 amp charge and after 60 miles or so settled in to a nice steady 8 amp charge at "cruising speed". I assumed that perhaps the commutator cleaned up, brushes settle etc etc. BUT, on occasion, when the revs drop, the ammeter shows about 2 amp discharge and the ignition light does not come on. ALSO, on occasion, when stopping the engine and ignition OFF, the ignition light stayed on !! Cutting the battery supply by the master cut off switch obviously put the ign light off.
Looking inside the CF3 cut out, the spring holding the contacts open looks OK as is the braided wire from the moving contact to the solenoid coil. I am reluctant to aggressively clean the contacts inside the cutout, and normally clean them by 'sanding' with a piece of clean card slid in and out a few times, then clean with alcohol.
My prognosis is that the spring inside the CF3 has become too weak to pull the contacts apart and needs to be shortened ??
What do the experts say ??
Bob