Hey, I am helping out one of my friends restoring a 71 Mustang Mach 1. We know jack schitt on tuning a carb though... a read a few internet guides and was able to get the idle mixture close, as in it runs without knocking or sooting. The carb is a new holley unit. The goal is to, without a dyno and all that, tune it well enough to pass emissions even though the cars came without a CAT. The car only has to pass once, and its good forever.

So how is it done?

Also, the idle-throttle stop is backed all the way off, and the idle is still a little high. Any fix? We want to get it to around 900, currently its at 1100.

 

Keep cranking mixture screw in until no idle readjust idle screw and trymix screw again. Seriously, when you get it on the road, have it dyno tuned, esp. if the fuel economy is bad. It will pay for itself. In the meantime don't forget to pull the plugs, make sure they aren't white or flecked as in way too lean. Listen for pinging. Initial advance between 10 and 14 some cars like the advance, some don't care too much. Set advance, then take it out and flog it. Repeat as needed. Remember dyno tune for best power and fuel economy. Have fun, Dan