Ok so I'm getting 20.4 or so mpg with my holley 1945 right? and I rebuilt a bbd and got 17.8 mpg but I couldn't get it to tune so I got a carb from an auto store and no I'm stuck at 14.6 mpg! Now I did have a nylon dis gear eat its self so I changed it and put on a new timing chain at the same time. You guys time its the timing? Im stuck. thanks

I dont have an idle inrichment valve on the carb Im using and the other one had no provisions for one. Is that the isssue?

Buying a "rebuilt" or "remanufactured" carburetor at the parts store practically guarantees you will get garbage.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Two things come to mind. You ask if we think it might be timing. Does this mean you did not set it with a timing light? The othjer item is related to the timing chain. It is possible the cam timing is off.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

The Valaint got unbelievable mileage when the chain skipped. Of course I had to drive at 30 mph in 5th gear....
Changing the chain reduced my mileage...but now I can cruise at 75 in 4th......

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Yeah....Im the one who destroyed this rare, vintage automobile.....

Remove the parts store BBD and put the old one back on. Then adjust the metering rods as described here

Guys dont get me wrong the car runs great with the carb it has on now but the old bbd wouldnt tune to save its life. I guess I'll rebuild it again and see if it wants to run right. I just thought that if my timing wasn't set just right it wouldnt use the gas in the cylinders the best. Thanks for the info on the rod ajustment I do have those measurements but maybe the carb wasnt cleaned out all the way. Oh by the way can you use a ebrok or afb accelerator pump in a bbd???