Dave I fixed the dizzy today; I used a scrap piece of Lexan, I used then the 3 blade metal part on the underside of the advance plate as a pattern. Works well and the air gaps between the reluctor and ring are pretty much perfect.

I should have made two pieces becuase when I popped the cap off the distributor from the spare A15 low and behold I immediately saw the little BB lying inside. Obviously that one as an issue as well.

5/32 sounds right as I measured them at just shy of 4mm.

Tom

Center hole is 7/8", ball bearing holes are 5/32"

The ball bearings are the correct thickness to locate the two plates without wobbling. The plastic/aluminum thickness is not critical if you put the bearings back in. Normally the only part to break is the plastic spidery three-lobed bearing holder. If you make a bearing holder from a big disc of plastic, it works well, is fairly easy to do and ... I think it will hold up long term

I have seen a couple of matchbox distributors with METAL bearing holders. Maybe they are the service replacements? Nearly all of them have the super-light plastic holders

That'll work. I fixed many of them that way (and the vacuum advance still works). The ball bearings fix the two plates together and prevent wobbling

When the stock plastic bearing reatainer breaks, the ball bearings fall out and the plate assembly wobbles. Since the stator signal ring it bolted to the top plate, it allows the signal ring to wobble causing high RPM issues

Cut a disc out of polypropelene, drill a 1" hole in center, and three small holes for the ball bearings. Reassemble. More information

So one of my D4K matchbox distributors had the typical vacuum advance plate bearing issues; so after disassembly it occurred to me that as the vacuum advance is not hooked up there my be a simple fix.

The plastic bearing piece is 3.5 - 4mm thick. If I simply cut some of right thickness and bonded or bolted it to the existing plate that would keep the magnetic ring from wobbling about. I'd still use the vacuum diaphragm to locate the plate properly.

A new plate from Nissan is $75 if you can find them but as I don't use the vacuum advance it seems like I might as well make one out of aluminum or plastic etc.

Thoughts?