club car cuts out/backfires after half mile

[gqe9580]

93 club car starts up fine, runs on street at top spped for about half mile,then cuts out/backfires. Seems to be only when engine is cold. Cannot reproduce this with hot engine. When this backfiring occurs, with the pedal to the floor, the cart lurches a couple feet,cuts out,lurches and eventually will come out of it and run like nothing was ever wrong.
So far I have:
1. replaced spark plug
2. replaced air filter
3. replaced fuel filter
4. pulled carb, cleaned all jets and ports w/carb cleaner and compressed air
I guess there could still be a small particle of dirt in there, there was a small amount of debris in the bowl. I don't get the hot/cold thing though.
I don't know,maybe it's electrical. But I my experience with small engines, bad coils cut out when they are hot, not cold.

Any thoughts would be appreciated.