'76 R90/6 with 90k miles - I have had several airheads over the years, sometimes taking a detour to Brits or (sorry) Harleys, but I have never had this happen before. I have been chasing a problem where the ignition breaks down coming off idle. I rebuilt the carbs, replaced everything electrical in the ignition circuit (some a couple of times) and today, after installing a new advance unit, I started her up with the cover off and, holy crap!, the connection to the points is arcing over to the advance unit! I put a piece of masking tape over the connection at the points and it fixed the problem - I'll replace that with some liquid tape. I guess this was the problem the whole time, but I have never seen this. It seems to me to be a design error, but is there something else going on here? These are OEM points.
During a rushed installation, the front engine cover could have caught the ignition wire between the cover and engine. When the cover was tightened, the insulation would have been cut through. This is a common error when replacing the front cover. You might want to secure that wire out of harm's way.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
I’m having trouble, in my head, envisioning where this arc is occurring. I will share that I experienced an intermittent ignition failure where the spring for the points would touch the head of the lower mounting/adjusting screw for the points plate. The spring passes very close to that screw head. Touching kills the ignition. I changed to a new set of points and eliminated a washer on that mounting screw. Think I had an extra washer there somehow. Never happened again. I think some OEM points “ain’t what they used to be” - who knows where they come from.
I had a set of points where the tension spring wasn't seated fully- and it just barely touched the timing unit. Once i ran it with the cover off I found the problem, but not before a lot of messing around with it. The spring seated with light presssure and all was well. 1976 R75/6
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