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Discussion Starter #1
Hello and thanks for any and all help with an "idle" concern. I recently bought a nice 4K mile '03 999. I have searched prior 999 idle threads with no direct discussion of the following issue. I also have a service manual with vague pictures.

My 999 has a 1/2 termi system "kit" that as I understand included a DP ECU. Ducati Austin I believe mapped/tuned the new ECU. Rest of FI system etc. is stock.

Idle speed 95% of the time is a low 750 +/- ~ 75RPM, a seemingly low but nice cammy idle. Sometimes, after riding anywhere from a few to 100 miles, randomly it'll jump to 1000RPM +/-, fast idle lever full off, handlebars straight ahead position (e.g., stopped at light). Idle to 9500RPM is smooth, strong and linear with very nice off to on throttle transition regardless of idle speed. Starts up fine cold and hot, although slightly sensitive to load when I take off as it's warming up. Very rarely and only within the first 1-2 minutes of running has the bike ever stalled when coming to a stop. Between tall stock gearing and low idle, taking off from a stop can be dicey (I try not to slip the clutch or rev too much).

After reading the manual, it appears US bikes have "plugs" in the left side of the airbox. I have removed plastic 3/4" wide rear plug and a large rubber "grommet" (~2"X2") near the front of the airbox left side just behind a frame rail and can see various throttle linkages through both holes.

My questions are these:

1. Are these the correct access plugs?
2. Are the air bypass screws the brass screws located near the base of the throttle bodies? I have attached pictures of both. The front TB seems to have the ab screw located just inboard of the throttle bracket assembly through a hole in the bracket (bottom picture, just to the right of the fast idle cable attachment point). The top picture TB has a similarly located screw in the lower left part of the TB.
3. Is stock idle speed 1000RPM (seems 1100-1200RPM is the preferred range)?
4. Is a long screwdriver the proper way to access the ab acrews?

Thanks for any and all help.
 

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dww,
1) Yes
2) Yes
3) 1100-1200rpm is the target. However, my '06 999s, with properly balanced throttle bodies, has been idling happily for over a year at an indicated 1000rpm.
4) Yes

As a confirmation, the picture below shows both the TB balance screw and air bypass screws.

 

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Discussion Starter #3
Thanks very much.

Excellent picture. I'm very grateful for your taking the time and effort to help me. I'll back out each screw maybe 1/8 turn at a time to prevent cylinder imbalance. Thanks again.

Dave

dww,
1) Yes
2) Yes
3) 1100-1200rpm is the target. However, my '06 999s, with properly balanced throttle bodies, has been idling happily for over a year at an indicated 1000rpm.
4) Yes

As a confirmation, the picture below shows both the TB balance screw and air bypass screws.

 

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dww,

Below is a link to where I posted the carb balancing procedure I used which completely solved my stalling issue and resulted in a rock solid idle at 1000rpm.

Balance Procedure
 
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