I was wondering if any electrical experts can help. It relates to a M21 with an original MCR2 regulator. I have just got the bike running after restoration. The ammeter shows a charge of over 4 amps when engine revved above idle. However when idling with every thing turned off the ammeter shows about 4 amps discharge. As nothing is on I would have thought a zero reading as ignition is magneto. I placed an ammeter between battery positive (pos earth) and frame with engine stopped to see if any current leaking to earth but got a zero reading. Everything works otherwise and while running or stationary no wiring etc feels hot indicating a short.
It sounds as if the cut out needs adjusting. Maybe half a turn in on the screw might do it. When the voltage from the dynamo drops below a certain amount the cut out should open to stop the battery discharging through the dynamo windings.
