Relationship between idle jets and idle mix screws |
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Relationship between idle jets and idle mix screws |
era vulgaris |
May 9 2016, 04:06 PM
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#1
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J is for Genius Group: Members Posts: 982 Joined: 10-November 13 From: Raleigh, NC Member No.: 16,629 Region Association: South East States |
How much can one compensate for the other?
For example, with larger jets and idle screws further in, could you tune a set of carbs identically to another set of the same carbs that had smaller jets with the mix screw further out? I want to experiment with going a little leaner at idle and seeing how my engine likes it. I'm trying to decide if I should order a smaller set of idle jets or if I can achieve the same result by just turning the screws in further. Basically, what is the difference? Don't they achieve the same ends? Obviously there's a limit on the rich side because there's only so much fuel a jet will allow to flow. But if you're trying to lean it out, what's the difference between going to a smaller jet or just turning in the screw? |
era vulgaris |
May 9 2016, 06:23 PM
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#2
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J is for Genius Group: Members Posts: 982 Joined: 10-November 13 From: Raleigh, NC Member No.: 16,629 Region Association: South East States |
Thanks for the info guys!
I already have an onboard AFR gauge, so I know exactly how rich or lean I am. My issue is that sometimes at idle the rpm's start to drop and the car wants to die. Happens maybe once every twenty or so times I come to a stop. Happens a little more frequently if it's the 2nd or 3rd time I've driven the car in the same day. But sometimes it doesn't happen at all. I thought it might be from running too rich at idle. I have no issues at any other point in the rpm range. No stumbling, hesitation, or anything at all. It's just annoying to have to sit at a light every now and then with my heel lightly on the gas pedal to keep an idle. I was just trying to find out how far up into the rpm range the idle jets had an effect. Sounds like I maybe just want to bring the mix screws in a bit then, if the only effect they have is on the idle and not any farther up. |
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