Adjusting Fuel Air Mixture

[73DusterDriver]

Ive got a 73 duster slant 6 with a 1920 Holley carburetor, she runs really rich how can i adjust the air fuel mixture?

 

[RustyPlymouth]

at idle or driving around. if it is at idle you can use the screw at the base of the carb. turn it in a little at a time until the motor starts to stumble then back out a half turn from there. if it is running rich when you are driving you are going to need to change the jet. you could also try running a hotter spark plug.

 

[805moparkid]

ok you have a couple things you need to do. first off is check the idle air bleed (looking down the throat of the carb its going to be the small opening closest to the head(hit the throttle to see the pump hole, not that one).

using a drill bit gauge what size it is, should be about .035" and i bet if its rich its either plugged with junk or from the factory.