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JFairman JFairman is offline
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Join Date: Jul 2006
Location: S. Florida
Posts: 7,289
Feel free to adjust the idle CO adjustment screw. You won't learn how and what it does if you don't.
It's good to have a wideband AFR gauge in the car so you can see what it's doing and how it works out the next day you drive the car after a complete heat cycle.

If you've tuned carburator idle mixtures or lawn mower carburator needle valves by ear in the past it's the same except you turn the CIS idle mixture screw the opposite direction to make it richer. Turn the CIS CO adjustment screw left for lean and right for rich.
If you turn it a little just remember how far so you can turn it back the same amount if you decide to. The final adjustment should always be clock wise to keep your adjustment stable and consistant.
It does change air fuel mixture at upper RPMs a little as you adust it for idle mixture but not as much as at idle. There's a curved slope to the AFR change if you could make a graph showing it.

It's funny how some people here try to make such a simple thing so dramatic... lol
Old 10-08-2014, 01:34 PM
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