High Erratic Idle and Exhaust Popping

[Michaelr11]

Bike is a 2001 R1100RT with high mileage.  The bike is ridden on a regular basis. Not asking for help here; just providing some feedback for others to use.

 

For the last couple of years I have been fighting against a very erratic/lumpy idle, and popping on closed throttle deceleration (engine braking). I have tried to minimize these problems with tuning adjustment with limited success, but the issues have continued.

 

The idle started running higher with the motor at normal operating temperature and last week the idle started running so high that I parked the bike to make a more complete analysis.  I found that I could make the idle change by spraying carb cleaner or brake cleaner around the throttle bodies. I changed out the right TB and tried to balance the idle. I could not. The left side was trying to run much more than the right. Even with the big brass screw completely closed, I couldn't get the idle to come down. The left side was pulling half of the vacuum of the right side. There was a significant air leak in the left throttle body.

 

I got a left throttle body. Cleaned it, replaced the o-ring on the BBS and on the end of the TB connected to the air tube. I moved the TPS over to the replacement TB and set the idle voltage to .380. Eyeballed both throttle cables, so that I could verify they were landing on the throttle stops and they were lifting off at the same time. The bike is now running like it was for years before. At stops, the idle drops down to a steady smooth idle. At curves and approaching a stop when decelerating, the motor slows the bike down with no popping from the exhaust. And this was all before I came back home and fine tuned the idle and off idle sync. Both of these required only slight adjustments to the big brass screws for idle, and one throttle cable for off-idle sync. With the Harmonizer, I could get the idle to ZERO difference, and off idle to below 10 - these are tiny differences. On a TwinMax you would call it perfect.

 

Bottom line:  Exhaust popping, idle that keeps dropping and returning, or just stalls when stopping, big brass screws that will not change the idle - these may have other causes, but you should check for air leaks at the throttle bodies. There are rebuild kits available for both TBs, that replace the butterfly shaft which wears significantly over time.

[Michaelr11]

I forgot to include one more benefit…. all surging is gone.

 

[dirtrider]

1 hour ago, Michaelr11 said:

I forgot to include one more benefit…. all surging is gone.

 

Evening Michaelr11

 

Ride it for while more then post back about the surging, I have my doubts that the surging is gone, reduced maybe but gone, I have my doubts. I have seen this before, after doing fueling or intake work the surging seems gone but the motorcycle just hasn't been ridden in the surging range far enough or long enough for the surging to be noticed again.  

[Michaelr11]

On 7/1/2023 at 5:57 PM, dirtrider said:

Ride it for while more then post back about the surging, I have my doubts that the surging is gone, reduced maybe but gone, I have my doubts. I have seen this before, after doing fueling or intake work the surging seems gone but the motorcycle just hasn't been ridden in the surging range far enough or long enough for the surging to be noticed again.  

 

How far is enough?  Been out 4 times, a little over 300 miles, no change in the fueling profile at all.  Still idles smooth, and no surge.  This is how this bike ALWAYS ran when it was tuned up.  It was only when the ride changed and I could never get it back to where it should be.  The bike is stock - except for charcoal canister delete - working O2 sensor, stock RT cat code plug, no add-on fueling mod, stock exhaust with catalytic converter.

 

Does the MA2.2 even have fueling adaptations?  Does it learn anything, or just work from engine inputs (temperature, O2, TPS)?

I have disconnected the battery multiple times for maintenance and replacement.  The bike has always just picked up and ran from first start exactly the same as it did before battery disconnect. Never seemed to be learning anything. Just asking...

[dirtrider]

7 minutes ago, Michaelr11 said:

 

How far is enough?  Been out 4 times, a little over 300 miles, no change in the fueling profile at all.  Still idles smooth, and no surge.  This is how this bike ALWAYS ran when it was tuned up.  It was only when the ride changed and I could never get it back to where it should be.  The bike is stock - except for charcoal canister delete - working O2 sensor, stock RT cat code plug, no add-on fueling mod, stock exhaust with catalytic converter.

 

Does the MA2.2 even have fueling adaptations?  Does it learn anything, or just work from engine inputs (temperature, O2, TPS)?

I have disconnected the battery multiple times for maintenance and replacement.  The bike has always just picked up and ran from first start exactly the same as it did before battery disconnect. Never seemed to be learning anything. Just asking...

Afternoon  Michaelr11

 

The 1100 Ma 2.2 has some short term fueling adaption but it doesn't seem to have retained long term fueling adaption.  Disconnecting the battery on the M 2.2 doesn't require a TPS re-learn procedure.  

[Paddler]

Funny, I can't ever remember my R1100R surging.  At what RPM is it typically noticeable?

[dirtrider]

11 minutes ago, Paddler said:

Funny, I can't ever remember my R1100R surging.  At what RPM is it typically noticeable?

Afternoon Paddler

 

I am going to do you a BIG favor & not tell where the surging is, or how to get it, or at what speeds or RPM's it appears at.

 

If you don't remember your 1100 surging then keep those thoughts, keep riding it the way you have been & don't think another thought about surging. 

 

You can thank me when you sell that 1100 with pleasant thoughts about it not surging. 

 

The BMW surge is a nasty thing, once you discover it & tune into it then you will find it every time you ride one of those motorcycles, just let it be & ride happy.  

 

 

[Paddler]

4 hours ago, dirtrider said:

Afternoon Paddler

 

I am going to do you a BIG favor & not tell where the surging is, or how to get it, or at what speeds or RPM's it appears at.

 

If you don't remember your 1100 surging then keep those thoughts, keep riding it the way you have been & don't think another thought about surging. 

 

You can thank me when you sell that 1100 with pleasant thoughts about it not surging. 

 

The BMW surge is a nasty thing, once you discover it & tune into it then you will find it every time you ride one of those motorcycles, just let it be & ride happy.  

 

 

It's okay, you can tell me.  I don't ride that bike much since I bought my 2000 1250RS.  I keep the old bike because it was my first motorcycle, bought it new in 1998.  Also, it's a 75th Anniversary model, with the classic black with white pinstripes, spoke wheels, etc.  My buddy flies or drives up from LA and we do a once per year road trip.  He loves that old thing.  I won't let him in on the surging thing.

[dirtrider]

13 hours ago, Paddler said:

It's okay, you can tell me.  I don't ride that bike much since I bought my 2000 1250RS.  I keep the old bike because it was my first motorcycle, bought it new in 1998.  Also, it's a 75th Anniversary model, with the classic black with white pinstripes, spoke wheels, etc.  My buddy flies or drives up from LA and we do a once per year road trip.  He loves that old thing.  I won't let him in on the surging thing.

Morning Paddler

 

Check your Private Messages on this site later today, I will send it to you in a PM. 

[Michaelr11]

On 7/3/2023 at 11:32 AM, Michaelr11 said:

How far is enough?  Been out 4 times, a little over 300 miles, no change in the fueling profile at all.  Still idles smooth, and no surge.  This is how this bike ALWAYS ran when it was tuned up.  It was only when the ride changed and I could never get it back to where it should be.  The bike is stock - except for charcoal canister delete - working O2 sensor, stock RT cat code plug, no add-on fueling mod, stock exhaust with catalytic converter.

 

7/08 - over 600 miles.  No change.  Rides smooth with no surge, drops to a steady idle when I come to a stop. When hot, the idle is probably a little high, maybe 1200 rpm. I will lower that the next time I have the fairing off.