Surging Fixes

[Phil Y]

I know, I've searched. This article http://www.ibmwr.org/r-tech/oilheads/R11inj-surging-fixes.shtml (scroll down to the 4 of 4 section) recommends advancing timing, increasing valve lash and synching throttles as a surefire cure, assuming there are no mechanical problems. Has any one tried one or more of these techniques on an R1100S? Results?

[Jeff Williams]

synching throttles helps if the other things are fixed.
IMO a R1100S needs to change the fuel mixture with a chip,(fosterRad), a K-fuel regulator, or a fuel management system.
Remove the cat and muffler system with aftermarket, and a K &N air filter will put a smile on your face.
jeff

[Highlander179]

Originally Posted by Phil Y

I know, I've searched. This article http://www.ibmwr.org/r-tech/oilheads/R11inj-surging-fixes.shtml (scroll down to the 4 of 4 section) recommends advancing timing, increasing valve lash and synching throttles as a surefire cure, assuming there are no mechanical problems. Has any one tried one or more of these techniques on an R1100S? Results?

surging issues on '04 dual spark bikes? just ride it and enjoy

I thought surging was a white whale

[blutruck1]

Surging fixes: I wouldn't recommend:

Increase valve lash, engine is designed to run at the specified lash setting for the best performance compromise. You're messing with many hours of proven development time by BMW engineers, and I doubt you're going to do better than they have.

Advancing timing, you may or may not have knock issues depending on fuel grade/oxygenation. You may increase surging by over advancing/retarding and therefore wasting time. Also, you're changing injection timing doing this.

No need to increase fuel pressure by changing regulator. I doubt you'll notice any change without a different eprom.

I would:

Change plugs to Autolite 3922 primary and NGK DCPR7E in secondary. Cheaper and the bike runs noticeably better.

Do a TB sync as carefully and accurately as possible.

If you still have surging issues, then I would Techlusion the bike, cheapest and easiest, except maybe the Foster Rad doohickey, which can't be adjusted like the Techlusion should you change more stuff.

Make sure you REALLY have a surging problem before going further than plugs and TB sync.

[blutruck1]

One last thing I forgot:

Injectors. I have an 04 BCR with 18k and got suspicious of my injectors. Sent them to be cleaned/tested (RC Engineering) and found the following:
Before
Left: 297 cc/min Fair pattern
Right 315 cc min Good pattern
system balance of 6.1 (not real good)
After: 319 321
Left: 319 cc/min Excellent pattern
Right 321 cc min Excellent pattern
system balance of 0.6 (good)

You might take a look at your injectors too. I'm sure the imbalance and low flow will contribute to surging. Cost was very reasonable and turn around in less than a week.

[pwillikers]

All the fixes you cite are for the early, single spark, models. As suggested, make sure it is surging you're experiencing. As classically defined by beemersurgofiles, surging has a frequency of about one per second, is consistent in amplitude and duration, occurs at steady state throttle and is often observed to be most evident in fourth gear for whatever reason. Rum, Rum, Rum ... If your symptoms are other than described, the injector testing and balance is a very good suggestion as to how to proceed.

I wrestled with a surging '99 for a time. I tried all manner of incantation but found the most effective remedy was to do a careful "zero=zero" adjustment (defined in the doc link you cite) and an even more careful throttle body balance. Buy or borrow a twinmax for the latter purpose.

My bike's surging is now only barely evident and only in fourth gear at steady state. It's gone everywhere else. I'm quite happy.

[phoenixtexoma]

I bought a set of new matched .370 injectors from Russ Collins, mated to a K-bike fuel regulator. Get no noticeable vibration at any rpm and love the way the bike pulls in 5th & 6th gear. Just installed a NOS system.

[AndrewA]

I've only heard of one other R1100S that had surging issues (Carlton's). Are you sure that's the issue?

[ErricZ]

I've owned 2 '01 R11Ss neither of which "surged" nor did my 95 RS ... they DO have a sensitive throttle. Make sure the bike is in a good state of tune (new plugs, valves, rocker arms, etc) and relax the deathgrip on the throttle..

[Phil Y]

Let me update my progress: tried to advance the timing and couldn't even keep a decent idle so I simply put the timing back to where it was (TDC). Next, I took blutruck1's advice and didn't try the other recommended fixes. Instead, I got plugs blutruck1 recommended but upon removing my "old" ones (only about 500 miles on new plugs), it appears that neither of my secondaries are firing. Here's a pic:



1. Do you agree with this assessment?
2. If so, what could cause both secondaries to not fire?
3. Suggested cures?

Appreciate your suggestions!

[Deans BMW]

One of the best "Surging " fixes around is having San Jose BMW dual plug your heads, a lot of other bennys as well, more power, better fuel milage, etc.

[AndrewA]

I believe that the secondaries spark at a much lower voltage that the primary plugs do.

I'm not sure that they should have the same color as the main plugs.

A way to test if they are doing what they are supposed to do would be to pull the primary wire caps off of the bike. The bike should start and idle with the secondary plugs, yet wont rev. beyond 1500 or so rpm.

[hawkeyejohn14]

Originally Posted by Highlander179

surging issues on '04 dual spark bikes? just ride it and enjoy

I thought surging was a white whale

I owned a 97 R11RT that surged, mainly in third while trying to maintain a steady RPM, when not perfectly synched and valves crisply adjusted.

My 04 R11S has given me none of that, except for my recent unplug, she purrs. With a better exhaust system, she would ROAR. One day.... Ohlins first.

I am sorry to be of absolutely no help here.

[turboflyer]

Secondary plugs on the bottom of an opposed engine might lead one to believe they are not firing, they will most always be more fouled than the upper primary plugs. Oil tends to settle at the bottom of the piston and rings. Guess where the plug is. Not that they might fail but I would suspect not.

[Phil Y]

OK, I pulled a secondary plug wire, hooked up and grounded a good plug and started it up--there was a weak, yellow spark, not a fat blue one like the manual says there should be. Ordered new plug wires--ouch! $90 for two of them!!! We shall see.

Dean's BMW--Mine's an 04 and already has four plugs.

AndrewA--that test will have to wait until next weekend.

Turboflyer--that's exactly what I was thinking but I couldn't tell by the color (insulators are totally black/gray) whether they were even firing. They were, but perhaps not as robustly as they should?

Appreciate the inputs.

[hawkeyejohn14]

the plugs to use aluminum anti-seize compound on the threads of the plugs.

[roger albert]

First, you should not expect the two sets up plugs to look just the same. They don't look the same on even a well running factory dual-spark oilhead.

Second, as others have said, be sure you really have surging. All the stuff in the article you referenced works quite well on old single sparks, but is usually less necessary on the dual sparks (though, once in a great while, useful)

Increase valve lash, engine is designed to run at the specified lash setting for the best performance compromise. You're messing with many hours of proven development time by BMW engineers, and I doubt you're going to do better than they have.

That's half right, at best, and obviously comes from someone without a lot of M2.2 or M2.4 tuning experience. It is correct only insomuch that it is a compromise of a lot of parameters, and interests -- and isn't necessarily the best setup for an involved owner.

Advancing timing, you may or may not have knock issues depending on fuel grade/oxygenation. You may increase surging by over advancing/retarding and therefore wasting time. Also, you're changing injection timing doing this.

The knock-danger part is right. The latter portion off base, barring a really really incompetent adjust.

No need to increase fuel pressure by changing regulator. I doubt you'll notice any change without a different eprom.

And that's the very worst informed part of the advice. A good EEPROM makes a world of difference, as anyone with any experience with these knows.

That having been said, I agree that you need so see if this is really surging, and then if it is, try the basic ibmwr/Lentini stuff. It's proven, unlike some of the ill informed conjecture posted above.

[blutruck1]

Roger Albert:
Changing fuel pressure without an EPROM is pretty pointless as you quoted: "No need to increase fuel pressure by changing regulator. I doubt you'll notice any change without a different eprom."

I seriously doubt that anyone not in possession of a dyno and engineering degree is going to better the design specs of a particular mfg engine, but you may be the exception, especially regarding the EXTREME HP and TQ changes to be attained by changing valve lash.

So, he's not changing the injection timing at all when changing ignition timing? Really? What's incompetence got to do with changing the timing? Does it change injector timing when changing ignition timing or not?

Love when you chime in and don't read.

Yep, just conjecture on my part....

[Phil Y]

Just to clarify, the "surging" I'm experiencing is a bucking or jerky on/off feeling between 2500-3500 rpms at steady throttle with no load which is totally absent with any load, like riding into a headwind or accelerating. Acceleration is strong and without any hesitation, flat spots or surges.

Update: Cleaned the big brass screws on the throttle bodies and the interior, as best I could. Sync'd the TBs. Changed plugs to those recommended by blutruck.

Results: Condition improved but still present, to a lesser extent. Used to buck like a mule; now it just kicks like a donkey!

Project this weekend is to install new secondary spark plug leads and a K&N air filter. I'm hoping that the former will further reduce this effect. Will look into getting injectors cleaned if this does not reduce the problem to tolerable levels.

[R111S]

23AUG2004 - @19,135 Miles I followed the advice from one of my British riding buddies, Chris Barnes who owns a 2004 BMW R1150R Rockster, regarding Throttle Body Synchronization. While the engine is OFF, listen to the Throttle closure to hear the Butterflies hit their respective STOPS. Make sure that they STOP simultaneously during Throttle rolloff to Low Idle position. Mine did not STOP simultaneously. The RH side hit the STOP slightly later than the LH side. Chris said to only adjust the cable of the RH side (without the Throttle Position Sensor) and do not adjust the STOP Screws...no surging issues for my '99 with 58K Miles now.