I replaced the original carb on my 53 flathead v/8 with a ecg carb. It idles real good but when I give it the throttle it wants to back fire. Any ideas or suggestions? It has a 7.5 power valve and #51 jets.
I've always found backfiring to be a non-fuel related problem. Think about it; there is combustion occurring when the either the intake or exhaust valve is still open. So it's either a timing issue, or a mechanical problem like a bent valve. I have experienced both scenarios.
Why was the original carb replaced? Are you running with the OE LoadaMatic distributor? Is either carb compatible with the LoadaMatic distributor?
If it's lean-slow time-carburetor too big=pump bad=old gas=points set wrong=bad wires=weak spark or worn distributor bushings it can back fire and make your hair kinky. If it was ok before before swapped out I would bump the jet a couple sizes. Check the vacuum advance also. It could be on the wrong port. I like mine on ported vacuum at idle. Some people run direct vacuum for a smoother idle but you can get into a dieseling effect. Also try bumping the time a little can help if It don't kick back on the starter.
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