Gradually dies on idle

[JARichmond]

Hey all. I've been riding my XS for about a month and a half this season and have loved it . At the start of the season, I modified my bike to accept Emgo pod filters on my intake runners and modified my jets to 142.5 main on the left and 145 main on the right. The jet set up worked, but I was a bit disappointed with the calculated mileage. Compared to the advertised 65 mpg of other members, I was getting 35 to 48 mpg depending on my speed.
Because of the above, I've been looking for ways to improve my mileage (because that's the main reason I ride). After changing to 140.0 mains on both sides, as I had been advised, I have developed a weird idling issue (but a splendid 59.2 mpg ). Presently, my idle will not sit anywhere near the recommended 1250 to 1500 RPM. At the present time, the bike will often rev to 3.5k on its own or idle so low that it stalls, in the difference of 1/2 of a turn of the idle speed screw. I can't seem to find a happy medium until it's in a parking lot, when it runs as if nothing's the matter. I swear, it's playing games with me!

 

[16VGTIDave]

Clean your carbs. It sounds like the Pilot circuits are not operating correctly. In particular the pilot screws. The extra 1/2 turn of the idle speed screw is opening the throttle plates enough to get you on the Pilot jets.

 

[JARichmond]

UGH! I was hoping you wouldn't tell me to clean my carbs! Darn, I thought I'd be free and clear from cleaning carbs for the rest of my natural life.
The problem with it dying on idle is that it slowly reduces idle and takes just long enough to adjust the screw at a stop light, and doesn't act up in a parking lot. Any idea why this is happening? Or should I blame the XS gremlins for this, and just clean my carbs and get on with it?

 

[xschris]

Have you synced the carbs with a manometer?

 

[HoughMade]

UGH! I was hoping you wouldn't tell me to clean my carbs...

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