1500 ZS carb question

[ahpook]

You know that stupid little "idle richness adjustment screw" on the right side of the carb, looking at it from the fender? The Haynes manual says to adjust using a CO meter, which I don't have, nor do any of the local garages I've called. How does one set it without a meter, and what exactly is it there for?
Thanks for any help,
George

 

[Morris]

It allows air to bypass the throttle plate and jets there by leaning your mixture. You can set it by ear (piston lift method) or with a Colortune (ususually run you about $50.00). Or.... I am sure someone else knows a cool way to set idle mixture.

 

[sparkydave]

Most info I find says to leave it closed unless you're trying to fine tune it to meet emissions. I keep mine closed since I can get it close enough to run well with the needle adjustment, and I am exempt from emissions testing.

 

[ahpook]

exempt from emissions? me too. isn't it wonderful? I've been removing everything I can, emissions-wise, and the engine just runs better and better...

 

[sparkydave]

Yes, being exempt is a good thing. Here's hoping Ohio never decides to follow Pennsylvania's example. They didn't exempt old vehicles, and my dad's 1947 Lincoln failed so badly they couldn't re-calibrate their sniffer. Serves them right, expecting a 60 year old car with a V-12 and only a muffler to pass. Last I heard, I think he did say they finally came to their senses and made exceptions for pre-smog cars.