2000 R1100RS - Another idling post...

[mhallman]

Did my valves and bike sounds much better. Put new plugs in (Autolites 3923 - gapped to 0.31). Been trying to get the bike nicely tuned. Replaced some fuel hoses which solved other issues. Now I'm trying to focus on an idling issue. You can see on the video that it idles fine then wants to briefly cut out. Also, when I rev it up and chop it, I get a decent pop from the muffler (which can be seen on the video as well).

Going to be getting a throttle body tuner (Carbtune Pro 4) to make sure that's good, but wondering what may be causing the two issues mentioned above. Tested the battery and it was 12.34 volts. Could that be causing the rough idle. Starts and idles fine when warm.

My thoughts are tuning idle with big brass screws and then complete throttle sync... Is this the next logical step? Anything else I should be checking?

 

[pauls1150]

Note the present positions of the BBSs (counting the number of turns, GENTLY turn In until Lightly seated, then turn out back to where they were), and draw a little pencil mark from the edge of the screw to the throttle body (for future reference).
Pull the screws out completely. There is often a buildup of crapitation on their tips; this can be wiped off, or if it's stuck, a rag with gas or alcohol will do it.
There is also often some buildup inside the idle air passageways. You can use a Q-Tip with gas or alky on it to clean those out, followed by a blast with a spray cleaner.... USE EYE PROTECTION, it will splatter back out. Since the cleaner dissolves oil, either make sure the intake valve on that side is closed,or remove the spark plug so it can evaporate more quickly.
If the condition of the O-ring on the BBS (idle air screw) is questionable, replace it ... or get a new BBS; I don't know if the O-rings are available separately. Take an old BBS with you, since there are two different body & thread sizes.
Are you familiar with aligning the TPS (Throttle Position Sensor)? Look for several threads in this forum about that. While the computer can adapt to almost any setting (and it will need a ride or two to adapt if you move it), it's nice to know that it's actually in the desired ballpark.
I also like to adjust my valves a hair on the loose side (to the dismay of some other forum participants); I firmly believe that this makes starting and throttle-body syncing easier. Pay more attention to the sync at idle and about 2500 rpm than at wide-open. The screws' and cables' adjustments will be reiterative (back and forth), but almost predictable.
My bike will also pop under some conditions (like sudden deceleration), but it doesn't really seem to be an issue.

 

[m_stock10506]

Valves, cold engine.
Warm up, 10+ mile ride.
Check throttle cables both sides have some free play before throttle plate moves
Idle balance with big brass screws, clean them first
TB sync by adjusting cables

If you are able, check the voltage setting of the TPS - throttle position sensor - at idle.
I like to set mine at around .375 volts - that's 375 millivolts.

The POP at throttle chop isn't bad and isn't unusual. If you are getting a lot of popping during engine braking slowing for a turn, I would check for air leaks at the throttle body connections.

 

[m_stock10506]

While the computer can adapt to almost any setting (and it will need a ride or two to adapt if you move it), it's nice to know that it's actually in the desired ballpark.

His 1100RS with motronic 2.2 does not learn anything about the throttle position and relies on the TPS voltage setting at idle.

 

[pauls1150]

Ah yes, the more primitive one than on the 1150s.... insert "Grrrr!" here.
Thanks, Mike!

Mr Hallman - you might find some useful info about TPS setting at
https://ibmwr.org/index.php/oilhead-r-bike-tech-articles/