Hi Jim, I hope the new pick ups will sort your problem out, there's nothing more annoying than something being wrong but difficult to pinpoint.
I made and used my own pick up gaskets in the end from some spare 0.8 mm thick Flexoid gasket paper. I used the Brightspark's brushes and springs even though the brushes marked the paper more than my old ones that I used last week to replace the Lucas ones.
Don't be too alarmed if the brushes from Brightsparks mark paper more than you may expect. As far as I understand it the outer surface is likely to have a covering of soft dust particles from the manufacturing process, which soon gets rubbed off. I'm trusting Brightspark's stuff to be 100% right for the job in hand
.
From what I have learned, the material carbon brushes are made from is critical for reliability and performance for the particular job they need to do and the same goes for springs. Everything must work together in perfect harmony. Brushes must not be too soft or too hard and the springs must be the correct length and strength for the brushes. We know the problem we get with brushes that are made of the wrong material but the same goes for the springs. If they are too strong, or too long or even if the brushes are too hard then there's the added danger of the slip ring's insulating plastic being scored over time. In a twin it's the plastic insulator that wears easier than the brass segment and then the brushes will have a little jump everytime from worn insulator to brass segment. Singles, having a continuous brass ring around the slip ring, do not have this problem.
My test after checking the continuity from center elctrode on spark plugs to carbon brushes with a multi meter and then fitting was a non stop 50 mph ride over Dartmoor (for 30 mins). A 30 min stop (engine was cut). A restart (fired first kick
) and the ride back over Dartmoor to return home. After a few minutes of arriving home and cutting the engine I started it again as a further restart test - and all seems well
.