Air screw-why does mine have an o-ring?

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from-the-Falcon
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Air screw-why does mine have an o-ring?

Post by from-the-Falcon » 10:33 pm Sep 30 2019

Just completed a full rebuild on a ‘99 200. Everything turned out great but It’s a bit rich off idle. Idle screw adjustments don’t seem to do much so I suspect it’s the jet block gasket. Have one on order.
In the meantime, I dropped the pilot from a 48 to a 42 and lowered the float height. This seemed to help a bit.
One odd thing I noticed but didn’t think much about until now is that my air screw has a spring along with a washer and an o-ring. I’ve only ever seen this on a fuel screw. Am I crazy, or does this not belong?
Not sure it would be the cause of my issue but just want to rule it out. Easy enough to remove, maybe it’s throwing off my setting? Going to also try lowering the floats a bit more and polishing the needle and passage.

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bufftester
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Re: Air screw-why does mine have an o-ring?

Post by bufftester » 11:53 pm Sep 30 2019

I know my carbs don't have an o-ring or a washer on the air screw, just the screw and spring. The Kehein parts view doesn't show one either. Where in the stack up is the o-ring? if it's o-ring on the screw first, followed by the washer and then the spring it likely doesn't make any difference. Only problem I could see is if the o-ring was at the bottom and somehow blocking airflow, but doubtful given the design of that circuit. My GSXR carbs have an o-ring, but they are also fuel mixture screws, not air. Either way, it's probably not a problem.

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Re: Air screw-why does mine have an o-ring?

Post by KDXGarage » 12:00 am Oct 01 2019

Welcome. Can you post a picture? Instructions are in my signature.
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Thank you for participating on kdxrider.net. :bravo: To post pictures here: "Full editor", "Attachments", "Add files", select the picture, "Open", "Place inline"

from-the-Falcon
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Re: Air screw-why does mine have an o-ring?

Post by from-the-Falcon » 08:49 pm Oct 05 2019

Thanks, I will post a pic when I pull it apart to replace the jet block gasket. The o-ring is at the tip after the spring and a washer just like a fuel screw setup.
I didn’t think it belonged there. Maybe I’ll take it out first and run the bike just to see if any difference.
First ride on it today. Freaking awesome but def running rich. Used 2 gallons the first 20mi. I think my float level is still too high and it might’ve been dripping a bit too.

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rungrandpa
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Re: Air screw-why does mine have an o-ring?

Post by rungrandpa » 11:09 pm Oct 05 2019

I replaced my air screw with an aftermarket one with a knob on the end. It came with an o ring and spring. Works with or without the o ring. I left it in.

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