help air fuel mixture screw side to enrich

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buddy burger
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help air fuel mixture screw side to enrich

Post by buddy burger »

on a buddy 50 (keihin carb) which of screw or unscrew will make it richer? its different from carb to another

thanks!
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tenders
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Post by tenders »

Out is richer, in is leaner.

At least that’s what I carefully made a point of writing down in my notes when I last was fiddling with the carb.
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babblefish
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Post by babblefish »

tenders wrote:Out is richer, in is leaner.

At least that’s what I carefully made a point of writing down in my notes when I last was fiddling with the carb.
I guess the idle mixture screw for a 50cc engine is different from the 125/150cc engines. On my 150, the mixture screw adjusts air flow so turning it IN reduces the amount of air resulting in a richer mixture.
Some people can break a crowbar in a sandbox.
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tenders
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Post by tenders »

I don’t have a larger Buddy to compare to but idle mixture screws work in opposite ways in different carb designs. Some control idle air, and some, idle fuel. My notes on my Vespa S150 suggest that its carb works the same as the Buddy 50, though I’m not 100% sure of that. Both are Keihin carbs. I have an old inboard boat engine that uses a Zenith carb, and it’s the opposite. In stock carb adjustments, you’re usually trying to set it between two extremes of “too rich� and “too lean,� and which extreme is which doesn’t really matter.
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