Thread: carb pop back

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well my 350 runs fine except for when I mash on it, then about 40% of the time i get a loud pop through the carb then the car takes off. not sure what it could be. Im going to mess a bit with the timing see if that gets it but does anyone else have any thoughts on what it may be?

sounds like timing or valve adjustment... check timing first... if that doesn't solve it... pull the valve covers

Originally posted by thesals
sounds like timing or valve adjustment... check timing first... if that doesn't solve it... pull the valve covers

Yay verily

I did switch over from points to hei about a year ago, it has a new cap and high out put coil(both with about a month and a half on them) with a msd 6al ignition. Ill check out the distributor shaft when I get off. slow acceleration is fine, It was a bit jerky below 2k but that stopped after a carb adjustment.

Denny W ; Your right about the distributor shaft, People often over look them. I had that happen to me with a 73 VW bug, one cyclinder would load up with fuel then back fire up threw the carb.
The distributor shaft was worn out.


~ Vegas ~

kool Thanks for the help ill run down the list when I get off this afternoon. Vara, was it a constant thing or somewhat like I discribed when ur shaft went bad?

well I put a light on it and it would seem that the timing is at 0 at 1k with vacuum undone. Im going to have to redrop the distributor because it is fully advanced due to the advance it self manifold/carb so im hopin that is all my problem. I did a hot adjust on the vavles anyway. my distributor shaft feels alright but it was used when i put it in so im thinking i might replace anyway.

you need more fuel, preasure or volume. do you see fire comming out of carb ? If you do, then adjust valves- intake opening- exh.closing, that is,- any cylinder that you choose to adj. turn crank until intake starts to open- stop adj. exh. valve, turn crank again until intake opens and is almost closed-stop and adj. exh. valve.this works for all types of cams!