On my MVVS 116 twin, the spring in the spark plug cap - on one side, is broken in half. This makes a sloppy contact with the top of the plug. How can I change the spring with a new one?

mvh.: Jan Eirik Olufsen - Oslo - Norway

I forgot to mention - the ignition is of the "old" type - up to 6 Volt style.

mvh.: Jan Eirik.

The Vlach ignitions that have the shielded plug boot and contact spring are not made anymore because the producer ended his business.
You can fit a snipped ball point pen spring inside the cast part. That will work well. There need not be more than slight contact with the flat plug top.
Leave the remainder of the old spring in place.