carb rebuild, now sputter

[boating lang]

I have a 71 or 72 9.8 thunderbolt type a carb. I recently replaced the needle and associated parts and cleaned the carb while I had it apart. I replaced all the fuel lines and vacum for pump and rebuilt the fuel pump. I can start it idles decent, when I throttle it up, it sputters and sounds like if may be backfiring a little bit. I am not sure if it is a fuel issue, timing issue or something else? Oh yeah, new plugs as well.

 

[Mi duckdown]

Re: carb rebuild, now sputter

Serial number. Idle adjustment(sp)

 

[boating lang]

Re: carb rebuild, now sputter

The serial number is: 2937906, not sure what the idle adjustment is?

 

[racerone]

Re: carb rebuild, now sputter

Front of carburetor , upper right hand side.---Open the low speed mixture adjustment 1/4 turn at a time .--See if miss goes away.