[Hal Copple]

you will get lots of suggestions, especially from drivers who have had this or that cause a similiar symptom.

If you are "popping" on decleration, then you have unburnt gas going out into your exhaust. While a worn distributor gear can cause late ignition, i agree with the above folks who suggest a carb issue. A distributor gear issue would not be intermittant.

I also agree that learning all you can about your carb is a useful place to start. I bought about four Holley books, and studied theory and application, but of course, still made errors when i tried to do things to my carb. But i got better in time.

My first suggestion would be to check your float level, remembering that the NUT does the adjustment, the SCREW is only to lock the needle valve. If you have not done this, ask for some suggestions on how to avoid a carb fire.

check your timing, too.