In Reply to: Re: Problems with Points posted by JMOR on May 21, 2019 at 08:58:09:
I bought a replacement NAA dust shield that was advertised to fit the late 8N and NAA tractors. It looked like the first photo JMOR provided. It did physically fit, but then the tang on the cap only engaged the slot in the flange of the dust shield. The only thing keeping the distributor cap from turning side to side is the two spring clamps. The distributor cap can shift. I doubt this is bad enough that it would keep the spark from jumping to the correct terminal. Another minor issue was less spring tension between the rotor button and the center terminal in the cap. The cap is raised by the thickness of the flange on the dust shield. This is probably also not enough to cause a problem, and that spring terminal can be bent up a little if necessary. I was mostly bothered because it obviously wasn't the right part. Later, the ad for that replacement dust shield was changed to say NAA only.
My original 8N dust shield looks like the second and third photos JMOR provided. The flange is a lot smaller and fits down inside the distributor body. It has a slot that aligns with the slot in the distributor body so when the cap goes on the tang in the cap engages both the distributor body and the dust shield. I have never seen a new replacement for the 8N dust shield offered by anyone. Just for grins I used a cracked but mostly whole 8N dust shield to make a mold, then made several replacement dust shields with a two-part Urethane plastic. They turned out fine but are tan color rather than black. My distributor didn't seem insulted by the change in color.