. Points were relatively new (6 months ago). Taking a good look at the dizzy, it looks like the points have been fouling on the dizzy wall 
.I'll try to explain it, as the photos I took don't show it clear enough. The points have two pieces:
a) a spring steel part with a lead hanging off it that is under +12V, and
b) a (much thicker) part that has both the pivot point and adjustment hole that is earthed through the dizzy body.
It is the latter part b) that was fouling.
The dizzy main body internal has two "lumps" inside. The "lumps" act as nuts for the screws that hold the distributor cap clamps on. It is one of the "lumps" that is fouling the points.
As the breaker plate inside the dizzy tries to return under spring tension, the points rotate with the breaker plate, and were hitting the "lump", preventing the breaker plate from fully returning. As the car has been operating (and the breaker plate frequently turns between advance and retard), the points get repeatedly hammering by the lump. There is a distinct mark on the points where the lump has hammered it. The repeated hamering appears to have helped close the points gap from 0.012"-0.016" back to 0.005".
If I open up the gap in the points, the points now longer hit the lump. However, to do this means that the points gap is way too big - at 0.016", the lump still clashes. If I bend the "part b)" portion of the points slightly away from the dizzy wall, they no longer foul, and all is well (picture a much relieved Harv going for a test-drive late this afternoon).
I've tried both Bosch GB504 points, and Echelin CS323V points - both seem to foul. Dizzy is a standard Bosch FB/EK item (7417802 part number on the plate riveted to the dizzy body).
Anyone seen this before (or is there something really, really simple that I am missing here
)?Cheers,
Harv.
