Backfire through carbs

[Jimkayh]

Any help is appreciated. After I had the carbs rebuilt I began to have a constant backfire at all speeds. When I disconnect the #1 spark plug wire the backfiring stops. I have replace wires and distributor cap.

 

[Jim 58 BN6]

Well, the first thing I would check would be that the plug wires were replaced on the cap in the correct order. From what you are experiencing, I think you might have a couple swapped, especially since it does run, and the backfiring goes away when you remove #1, so probably #1 is swapped with another. GL, Jim

 

[RDKeysor]

For sure having two spark plugs incorrectly connected--it has to be two--will give you some rip-roaring backfiring. Did that just last week!

 

[dklawson]

Once you confirm that the firing order and plugs are correct, turn your attention back to the carbs. Make sure they are working. Check the level in the float bowls and go through another mixture adjustment. Make sure the vacuum pistons are free and not binding in their travel.

If you have not touched the ignition system and start experiencing backfires from the carb it is often a symptom of an extremely lean condition... like running on one carb.