Abnormal Idle change and history

[tkbaker4]

I need some help trying to figure this out.
I’m sorry if it’s a little long winded but it might help explain why I need help.
First, a little background.
I bought my first BMW, a High Mileage (72k) ’04 R1150RS, in October ‘07. Couldn’t pass it up. It was $2k under Blue Book, in pristine condition, and loaded with after market upgrades, Ohlin Shocks, Cee Bailey windshield, Motolights, brake light modulators, wired for heated gear, luggage system with system cases, etc. The PO had obviously used and loved this bike over the previous 4 years. It was a great deal. The owners manual has all the appropriate service stamps from Bob’s BMW and then from Bloodworth’s here in town. Bought it from Bloodworth’s, the PO had upgraded to a new K-series. When I bought it I went over the service record it had accumulated at Bloodworth’s, (Tires, normal service, fuel pump.)
Let me tell you, it took some getting used to. I’ve been riding vintage Triumphs since before they were vintage (I’ve owned my ’70 Bonneville since ’76, second owner.) The power, handling, shifting on the left, fairing, all were something I had never experienced.
The bike ran like a dream and I had a great late fall alternating between the two.
Then,
Day after Thanksgiving, I tried to put it on the center stand while still astride it, overbalanced and dropped it gently to the right. Because my finger was caught between the handlebar and the top of the lawnmower it never went all the way over. No harm no foul, at least to the bike’s heads or Tupperware. My finger is still sore.
Rode it a couple of times in December. Everything was fine. On Christmas day I was going to go for a ride but discovered that when LOML had spray painted a chair in the garage she had deposited a fine mist of red paint all over both bikes. GRRR, I cleaned the Koi pond instead. Next day, I washed both bikes. When I started the BMW, It was idling low and misfiring. Thought it was a “wet” issue, blew it off with compressed air and put it away.
Next few weekends, it still was not running right. Went by the dealer and asked what they thought it might be. Told them my new GS-911 showed no faults. Their response was to make sure the throttle cables are seated correctly (they are.) Check the canister (It’s been removed some time ago.) Do you have a Twinmax? (I said, “I do.) Try a TB Synch. Other than that we’re stumped.
I bought 4 new plugs for it and went home.
Next day, changed the plugs. Dirty, but did not appear fouled, though idle did improve some.
Following the instructions of the TBS4Dv1, I did my first TBS.
Here is where you wrenchers come in…
Bike is idling at +or- 850 to start at operating temp
Initial BBAS settings were Right 1 1/8 L ½ (there is a problem here to begin with, right? A possible air leak somewhere? Where do I start looking?)
Since the bike HAD been running great at these setting I decided to go ahead with the TBS.
Twin max was pulling left at idle if I remember correctly.
Went thru the procedure, got the idle to around 1100+.
BBAS new settings were Right 2 ¼, Left 1 ¼.

I haven’t had a chance to run it on the road since then, it’s been too cold or wet. Hope to be able to this weekend.
I would love any input from you REAL wrenchers out there. I’m able to keep my Bonnie on the road so I know something about carbs, tune-ups, and valve adjustments. It’s just that this bike is a complete new technology for me and with no prior experience, I can’t even begin to diagnose some of these issues because I’ve never experienced them on this bike.
I apologize for the long post but I thought it best to get the most info out there at the front so you understand the bike’s issues and mine.
I love this forum and this community! And my BMW!
Thanx in advance.

Tom

[jingdog]

Ha your idle settings on the TBs are bogus 2 1/2 for one 1 1/2 for the other. Something is wrong. Air leak at the rubber boots holding the TBs to the heads or a throttle shaft worn (probably right side) . Strange it started acting funny all at once though. If its clacking a lot its the TBshaft. You might just be used to the noise though. Put your finger on the cable pulley on the right TB with the engine running. (dont get burned) If the noise goes away loose throttle shaft.

[PGlaves]

There are many variables at play - some of which are hard to chase. First, measuring manifold vacuum is only a surrogate measure for throttle plate angle, and throttle plate angle is only a surrogate measure for induction air flow. Several things, including deposits in the intake tract, deposits on intake valve stems or valve heads, combustion chamber carbon, etc all can cause airflow to be uneven side to side, even if the throttle plates are perfectly aligned, and even absent an air leak.

Directly - the idle air bleed screws won't match if there are any obstructions or deposits in the air passages. It little bits of gum or gunk where the screw tip seats.

Air leaks at the shaft have been mentioned. A hardened rubber inlet tube where the TBs attach to the head are also a possibility. So is the O ring between the rubber spigot and the head.

Personally, if I had a bike with 172,000 miles that stayed in synch as I powered through the rev range; that performed well while riding, on which I couldn't find an obvious air leak, and which didn't show a lean condition on one side when I examined the spark plugs with a chop test - I wouldn't pay one bit of attention to one air screw out more than another.

[bikerfish1100]

i would tend to agree with Paul's last few words- (paraphrased)- if it ain't broke, don't fix it.

[j-budimlya]

While agreeing with Paul on most of what he said......I would look hard at anything that coyuld have been "bumped" on the right side from the fall....

Checking for intake leaks is pretty easy with a spray of starter fluid or wd40 while the bike is idleing...

second, did you release all of the cables when doing the TBS?...if not, do it again with first loosening the cables.....
third, how long has it been since the cables where replaced?...if more than 30k miles....I would just replace all fo the cables...I have seen bikes where replacing the cables makes all the diffeerence in the world...

Of course, this should all be proceeded by a fresh valve adjust....always pays to start there....easy to do....and with that mileage, check the rocker end play....should be pretty tight in the spec range...

If none of that works...i'd try dropping it on the left side...never know...:)

Cheers....

[tkbaker4]

First, Thank you all for your thoughts. As I said, this is a brand new bike and technology for me and since I have no personal reference points, this helps a lot!
Something is wrong. Air leak at the rubber boots holding the TBs to the heads or a throttle shaft worn (probably right side) . Strange it started acting funny all at once though. If its clacking a lot its the TBshaft. You might just be used to the noise though. Put your finger on the cable pulley on the right TB with the engine running. (dont get burned) If the noise goes away loose throttle shaft.
Jingdog, I will check all of this though I've noticed nothing different from side to side. My problem is I don't know the bike well enough yet to be used to anything.


Directly - the idle air bleed screws won't match if there are any obstructions or deposits in the air passages. It little bits of gum or gunk where the screw tip seats.

Air leaks at the shaft have been mentioned. A hardened rubber inlet tube where the TBs attach to the head are also a possibility. So is the O ring between the rubber spigot and the head.

Personally, if I had a bike with 172,000 miles that stayed in synch as I powered through the rev range; that performed well while riding, on which I couldn't find an obvious air leak, and which didn't show a lean condition on one side when I examined the spark plugs with a chop test - I wouldn't pay one bit of attention to one air screw out more than another.
Paul, I will double check the tip seats. Carburetor cleaner on the tips and seats if I find any? Also will check the inlet tubes and O rings.
Chop test is running a nice long acceleration and cutting the ignition and coasting to a stop for a plug inspection, right?
I expect there to some differentials at work after 172k also.

i would tend to agree with Paul's last few words- (paraphrased)- if it ain't broke, don't fix it.
Bikerfish, agreed. however it was broke when the it suddenly refused to idle correctly and a fairly drastic BBAS adjustment was needed.

While agreeing with Paul on most of what he said......I would look hard at anything that coyuld have been "bumped" on the right side from the fall....

Checking for intake leaks is pretty easy with a spray of starter fluid or wd40 while the bike is idleing...

second, did you release all of the cables when doing the TBS?...if not, do it again with first loosening the cables.....
third, how long has it been since the cables where replaced?...if more than 30k miles....I would just replace all fo the cables...I have seen bikes where replacing the cables makes all the diffeerence in the world...

Of course, this should all be proceeded by a fresh valve adjust....always pays to start there....easy to do....and with that mileage, check the rocker end play....should be pretty tight in the spec range...

If none of that works...i'd try dropping it on the left side...never know...:)

Cheers....
Jim Bud, I HAVE seriously considered your last option.:laugh
First, are you saying spray the Starter fluid at the throttlebody connection and see if the is a change in the idle?
Second, I did not release the cables but I did check that they were seated correctly, and lifting at the same time, and that the there was identical play that allowed them to sit fully relaxed at idle. There is maybe a quarter inch of free play in the cable before they start to lift. Do I need to do it again? I was only working on the at rest idle at the time.
Third, I have no idea when they were replaced. Not in Nashville and I don't have the details from the longer service record at Bob's.

I do intend to do the Valve Adjustment and Rocker end play while waiting for spring. If I assume they were all done right last time it is my understanding that at 172k they shouldn't be drifting much anymore. But doing it myself gives me another base reference for this bike which the lack of is why I have to ask these questions in the first place.

My major concern was, as jingdog pointed out, that this was a fairly sudden onset of no proper idle. In my ignorance, I immediatley went to something electronic, not a wear or adjustment issue. Didn't even really think it was my inaugural tipover. There were several rides in the month intervening that were fine.
Curiouser and curiouser...:scratch
I appreciate all of your help. I'll keep plugging away at it and keep you posted. If any of you get any bright ideas or revelations, please let me know.

Tom

[j-budimlya]

There are two important "seals" on each side....one at the engine inlet, and one at the engine side of the TB.....they need to be vacumn tight....there is an o-ring at the TB side and a flat seal at the engine inlet side...if my memory serves me right....for sure you should tighten the bolts on the side and the clamp on the TB side.....both sides of course.....and you can spray around these joints with the engine running...if there is a leak...the engine will speed up a bit.....an inspection of this connecting piece may reveal a crack in the plastic....your parts have a few miles on them and can crack or distort and loose the tight seal....my guess would be that if there is a leak, it would be on the side where you have to "turn-in the brass screw" to get a balance.....because turning it in is closing a needle valve to reduce idle air flow.....for this side to be balanced.....the other possibility is that there is another source of air flow on that side......leaking TB....or TB that is not fully seating because the cable is not fully released with the throttle closed....to test for this when at idle....try to push the cable wheel further to the "stop" and see if it moves....it should not move......and while you are there.....you need to make sure that you have not had a small stone lodge in the channel under the cable....this will throw the TBS off by stretching the cable a bit.....even built up dirt will do the same.....on your bike, I'd clean the cable slot on the TB wheel ....

Aren't these bikes fun? Guess how I have learned about all of these potential problems.....yep, I had to hunt them all down myself.....and now its your turn...

Cheers

[jingdog]

Oh yeah that reminds me of a story about pebbles in the cable pulleys on the TBs.

[tkbaker4]

The mileage on the bike is 72K, NOT 172K as previously posted.
It has been corrected in the posts above.
I can only attribute it to my advancing lack of getting to the garage because of the cold.
I went down tonight to position the bike in the garage for a going over this weekend as the temps warm up and realized my error.
I am so sorry for the info error but i hope you forgive me.
the rest of the data is true.
Mea Culpa!:banghead

[PGlaves]

Tom,

Yes - that is a "chop test" as you described.

[bikerfish1100]

bring me up to speed, cuz i'm sure i'm missing something.
you oringinally stated that the bike was "idling low and misfiring". then, you did a TBS, and got an idle speed of 1100+, right where it should be (1050 +/-, according to the manual), but the BBS are not set at the same # of turns out. you haven't taken it out since. is all that correct?
Is your concern now that in doing the TBS you have found that the BBS are not set to where they are "supposed" to be? Are you concerned that your idle is not where you want it? or is it that that the bike might still be misfiring, but you haven't tested it to know?
I commented "IFAB, DFI"- to which you said it was broken. if it's just that the BBS settings are different, but it runs just fine, i would have a hard time calling that "broken". if it is still misfiring, or idling roughly, then yeah, something is still amiss, and you want to track it down and fix it.
so- clarification on current status?
(just trying to help, and needing some more info)

[tkbaker4]

Bikerfish,
Sorry for any confusion. As you and Paul said, I agree with the "if it ain't broke, don't fix it" philosophy.
TB Synch did get the idle back up.
The "Broke" i was referring to was that the idle dropped in the first place.
Everything was great before the unexpected drop in idle speed.
I guess I was ultimately asking what would cause that,
I have not re-fired the bike since finishing the sych. I intend to tomorrow as we are supposed to hit the fifty's.
That will allow me to recheck the idle and take it for a test run.
To all that have responded, I appreciate your help and will let you know the outcome.
As JimBud said, it must be my turn....:banghead

[PGlaves]

Bikerfish,
Sorry for any confusion. As you and Paul said, I agree with the "if it ain't broke, don't fix it" philosophy.
TB Synch did get the idle back up.
The "Broke" i was referring to was that the idle dropped in the first place.
Everything was great before the unexpected drop in idle speed.
I guess I was ultimately asking what would cause that,
I have not re-fired the bike since finishing the sych. I intend to tomorrow as we are supposed to hit the fifty's.
That will allow me to recheck the idle and take it for a test run.
To all that have responded, I appreciate your help and will let you know the outcome.
As JimBud said, it must be my turn....:banghead

The perplexing thing about the idle drop is that it didn't manifest itself immediately after the garage drop. If it had I would have suspected a drop related cause. Now it is gone. The abnormality (by the book) is the difference in bleed screw settings.

For what it is worth that was/is a permanent condition on Voni's R1100RS with the single wrap-around throttle cable system. As soon as the cable slack is eliminated between the two throttle bodies so they pull together, the idle balance goes off and can only be corrected by the idle air bleed adjustment. I've tried the cable adjustment by the book and every which way and that is the way it comes out. I get it synched at idle and synched on the cables, and ignore the setting of the screws. It bothered me for the first 100K miles and I have ignored it for the last 240K miles. I've concluded that is just the way that bike is.

But you might recheck the amount of slack in the right cable. And make sure there isn't a small stone or other debris in the sheaves (pulleys) where the cables run.

[Dave_Faria]

I have the same problem except it shows up after the engine has been run for a few minutes and is up to temperature. It is a miss that shows up at idle. I have also done the tbody sync, valve adjustment and rocker arm end clearance. I have even reset the right tbody stop and it was slightly out compared to the left tbody. The left tbody stop was used as a reference to the right along with a twinmax. My spark plugs also looked fine but, I replaced them anyway.

What I have been told talking to dealers and the Beemer Shop is they often see the "on the spark plug ignition coil" fail. I have also been told, And I can't remember where, is mouisture gets into the coil and causes it to fail. I have also been told that if one fails u might as well replace the other cause it's not far behind. The coils can be intermitten or totally fail. I have an intermitten coil.

My resistance measurements on my coils are 1.2ohms on what I assume is the primary and infinity on what I think is the secondary for both coils. Since the secondary is infinity u don't know if it is open.

Anyway I've ordered one coil from chicago BMW for $76(I think was the price).

I know the BMW GT-1 uses wave form analysis to determine if the coil is bad, and again from what I've been told, is that it is not always accurate. Again I've been told the dealer has seen a fair number of these fail.

Good Luck
Dave Faria
Austin, Tx

[Dave_Faria]

Got a new coil and changed the bad one. Problem fixed. No misses at idle. I cannot tell a difference in performance or vibration at speed.

Dave Faria
Austin, Tx

[tkbaker4]

After checking all of things listed above, I decided to dive in and start from the beginning.
Mustered my courage and did the OVAD following advice/instruction from the OVAD for Dummies post and the VonBaden CD.
It went well, all of the valve clearances were too tight. Only a couple of hours first time.
Also pulled the Brass screws. They were very gummed up and tarred. Should have pulled them to begin with! :banghead
Cleaned them and sprayed Throttle and Choke cleaner in the orifice.
Put it all back together.
Started it up.
Cough , sputter, PURRRRRRRR....
Re-did the TBS with the TwinMax, haven't rechecked the new adjustment measurements but they're about a 3/4 turn up from the 1 1/2 starting point.

It's running and idling fine now.
In a quick 25 miles around town, there seems to be a few flat spots under acceleration but I think they are evening out.
I touched so many things a the same time I can't pinpoint what I did but I'm leaning towards the gummed up Brass screws as the leading candidates.
I don't understand why the issue wasn't more gradual...
Thanks for everyone's ideas and support.
If there are more thoughts out there, I'd love to hear them.

PS
Dave, I wonder if I should get new "on the spark plug coils"?
Mine are OEM manufactured in '03 with 72K and 5 years on them....

[jingdog]

Glad to hear you had success! Any time the BBS's are off by that much relative to each other something has to be wrong someplace.

[Dave_Faria]

Spark plug coils should not fail - at least not for what we have paid for these bikes. If you have a few bucks and rat hole a couple it wouldn't hurt - the dollar and mark exchange will not get any better. My other BMW is a 30 year old airhead so I believe in spare parts especially those small enough to go under the seat while travelling.

In addition to replacing my bad coil I cleaned the coil ground on the back side of the cylinder. I ended up using a pencil eraser on the cylinder and 1000 grit on the ring lug. After cleaning I used an antioxodant for electrical aluminum connections. My best WAG aside from crummy coils was poor cylinder grounds caused the coil to fail.

If your bike was dealer maintained I've been told you can get the maintenance history. It might be interesting to look thru.

Glad you found your problem
Dave Faria
Austin, Tx

[devauxb]

...Also pulled the Brass screws. They were very gummed up and tarred. Should have pulled them to begin with! :banghead
Cleaned them and sprayed Throttle and Choke cleaner in the orifice.
Put it all back together.
Started it up.
Cough , sputter, PURRRRRRRR....
Re-did the TBS with the TwinMax, haven't rechecked the new adjustment measurements but they're about a 3/4 turn up from the 1 1/2 starting point.

It's running and idling fine now...

I was running into the same issues (one BBS was out about a turn further than the other and idle was still a little rough) and was glad I ran into this thread. I was first going to go down the 'look for an air leak' route, but decided to pull the BBS's first. Boy, I was suprised at the gunk/tar on both of those. Cleaned those off and squirting the Gumout Throttle cleaner down the orifice resulted in more black junk shooting back out.

Did a TBS and now see a significant difference in idle smoothness too! Best 20 minute tune-up yet (if you don't count the time where resat the Throttle cable that I had once knocked out of place - talk about rough idle!!)