View single post by DonBurns
 Posted: 06-20-2020 03:46 pm
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DonBurns

 

Joined: 09-18-2015
Location: Fullerton, California USA
Posts: 149
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 Thank you for the post. I have not seen much info on this and am very interested.

I also notice the big effect from the idle mixture screws. I balance using a CarbTune Pro, and have noticed there is a range of turns of the idle screws that don't have any effect on the CarbTune columns, or how it runs. But they do have an effect on the O2 mixture. What surprised me though was that the idle mixture screws also affect O2 mixture at higher RPM. I thought the "circuits" were separate. So I adjust balance and idle as best I can, Adjust idle mixture by adjusting mixture screws within the range of no effect on balance / column height, and if high RPM too lean or rich turn all four idle screws the same amount to get where I want. I don't have a box with all the jets and tubes. I try to get idle about 13, acceleration tends to go pretty rich, and cruising in the 12's.

I suppose the other indicator would be gas mileage. What do you see? Last fill-up was 15 mpg, but there was quite a bit of time running in the garage.