Tuning my CV 40mm carb using my wideband O2 sensor.

What AFR should I be shooting for at idle?

Cheers

I'm just guessing but 12.5  to  13.7 but what ever it's happy at and throttles best with.

i had a wide band afr unit a mate who tunes cars got me to use at drag strip to tune for more power. I've still got it laying around. I found what ever gave me the fastest trap speed was the best afr but the EPA might disagree.

Like krash said, give the motor what it wants.
Try bumping up your idle to around 1500, set
The AFR to around 13.5, or whatever the sweet spot is,
Then drop the idle and see how it runs.
This may make it a touch rich at 1000rpm.

I'll post a pic tonight of what I am seeing at idle....I'm thinking too rich.

This is for a blow through turbo ?
probably complicates things a little.

yes....there may or may not be a Turbo involved in the mix...lol

Regardless of the custom muffler system, the idle mixture is still controlled via that little screw under the carb and the pilot jet. I'm just not sure what a reasonable AFR should be.

Here it is....

if 11.7 is the afr too rich 14.7 is stoic more on later model cars / bikes I would say as krash 13.5 14 @idle to that 11.7 for boost/nos mtr at wot but as said
some mtrs like to be richer or leaner a set revs

Cherers guys.... I'll downsize the pilot jet from a 48 to a 45 as I'm only about one and a quarter turns out on the adjuster screw to get the 11.7.