Reply To: Problems gapping points on QD-19

[Don]

h20lew wrote:

I tried the way Mumbles described and that by far is the best way to do it. I’ve been doing it before by disconnecting the wires at the points and using a flashlight connected to the points and ground like some of the manuals show. The downside on that method was you always had to reconnect the wires and that brought in error like Fleetwin mentioned and you couldn’t really go back and verify it without disconnecting it all again. Maybe I’m misinformed, but I think the disconnect (no pun intended) is that most of the manuals on this were made before digital multi-meters were around and so the better method with the multi-meter and leaving the wires connected isn’t described in the common service literature from that era.

Just checked a 68 OMC manual, it definitely says to remove all leads from the breaker point terminal, which makes sense and is the “correct” way to do it. The key to success with Mumbles approach, is to have an ohm meter that can accurately show low resistance readings. The problem that I see most often is that many digital meters are erratic in this low range, admittedly I don’t have a high quality digital meter. When it comes to accurate readings in the very low range, I really like my very basic stevens AT101 analog meter. Opinions will surely vary, the important thing is to have a meter that is accurate in the low range and understanding how to set it up correctly. We are talking about a very small difference in resistance readings here, about one ohm, so confusion caused by inaccurate meter set up/readings can certainly create unnecessary confusion and frustration. The other thing to keep in mind is that we are not working on aircraft engines here…Trying to achieve absolute perfection when setting up the points is frustrating indeed, especially when crankshaft and mag plate sideways slop are factored in. I am usually disappointed when checking point set up with the timing light while running, after static set up with the ohm meter, never the same…Maybe using Mumbles technique will help…