Re-sync, re-sync, re-sync
 

Here's my problem...
I sync the throttle bodies and my 1999 R1100S runs sweet. Just fine.

However, after only a hundred miles or sometimes even less, I can feel that it is off. I have pulled the brass screws out and cleaned them, and inside. I even put a tiny bit of blue Lock-tite on the screws to be sure that they are not moving.

Any ideas guys?
:confused:

Assuming you have no funny air leaks (such as the vacuum port below the TB), do your tuning under load by riding around with dual vacuum gauges. Or far less adequately, with a battery TwinMax which tells you a whole less but gives the mistaken impression it is more accurate because it is shiny and expensive. The cheap meter on a TwinMax probably isn't durable enough for mounting on a bike - so that's another reason to ride with vacuum gauges.

If you keep the dual vacuum gauges on for a while, you'll see perfectly clearly if your synch'ing is drifting.

A picture of my jig for riding around with gauges on an R1100S and some discussion of under-load tuning with vacuum gauges is at my recently revised and far more accessible website, see URL below.

After making the mistake of wasting some time on your "elaborate" website! (laughable is the term that comes to mind first, actually...) I now perfectly understand why so many people here think bad about you...

You are an idiot IMHO! Bona fide at that... doesn't the constant talking out of your a$$ hurt over the long term?

For the longest time I was trying to stay neutral (not always easy) but, reading some of the garbage you write, I can now fully understand why people get mad at you...

I have a wonderful suggestion for you... take up gardening and start frequenting the gardening boards... there is so much you could do in terms of improving the fertilizer and application strategies, you'd be busy for the rest of your life...


As for Bob's problem... the only thing useful you had to offer was the fact that you pointed out the possibility of an air leak...

I am still laughing about "your audio club"... yeah, you strike me as such!

Could you stick your neck out and name a couple of the things you think are wrong and say why you think they are wrong?

Airleak is a good possibility.
Riding around with a twinmax is a very good idea.
I'm on my 2nd one over a nearly 15 year period (and counting) and use it nearly every day, so I've found it to be both accurate and durable. Some of the armchair guys don't really have enough understanding of science, or mechanics, or more importantly, actual experience, to be a valid source.

I'd also look carefully at cable routing and binding. In many cases, a cable that settles at a slightly different place every time (the bars are turned), will give a slightly different routing or end-seating every time, and thus slightly different sync every time. This is by far the most common cause of wandering sync on boxers, guzzis, and old ducs etc.

hth

Could a bad bowden box contribute to this problem? I often hear of folks saying these things start giving trouble on an older bike, although mine seems fine at 50K/10-yrs.

- Mark

good thought. One more place for cables to be a bit out of sync.
Either way, airleaks or, very generally, cable issues (to include bowden box) are the likely area, not the brass screws.

Gosh, I sure would have thought that mentioning the Motorola MPX2100DP in my vacuum gauge write-up would have established my electronic bona fides. Guess I was wrong. I hope others read my write-up and judge for themselves.

BTW, in one of my write-up I did the calibration of the TwinMax on max sensitivity. Ever wondered what you are reading on that tiny meter?

> Gosh, I sure would have thought that mentioning the Motorola MPX2100DP in my vacuum gauge write-up would have established my electronic bona fides.

Nope.

Bob, also go to a bike shop and for $10 bucks buy a cable luber.Its a little gizmo that you lock on the end of the cable and you insert the straw from an aerosol can into it and it pushes lube through the whole assembly.

I see you've let Ben back in:confused:

C'mon Roger, how about 52 years designing and building electronic gear and 48 years on bikes (but only the last 43 on BMW boxers)?

BTW, Bob K, if you have a 1952 BSA, take levert's advice. If you have a BWM certainly do not.

Bob K, are you finding this thread helpful?

It's obviously possible to do something casually a very long time, poorly and/or to remain easily confused/confusing

If it's not an air leak, another thing to check is to make sure you are snugging up the lock nut.

As shovelstrokeded said: 'I have read this thread with some amusement'.

From the latest Psychology Today:

'******'s syndrome' is a very rare malidy manifested by a repeated issuing forth of seemingly-technology-literate psychobabble from an ersatz expert bent on trying to impress the technically challenged.
Characteristics include getting slammed for trying to shut down technical boards by threatening lawsuits, repeated user identity changes while spouting the same inaccurate nonsense and championing idiotic technnical websites wherein every detail is simply wrong.
The recommended course of treatement is self-induced lobotomy by 45ACP or alternately drinking a quart of drain cleaner.
.

Use a propane or acetylene tracer to track down your air leak. If thats not it remember Jerry's suggestion to snug cable locks well. If thats not it you may want to make sure the butterflies left and right are equal........but don't get into this unless you know what you are doing. The bypass screws can mask unequal setting for the two butterflies. This has all been covered on this forum several times. Make sure your valves are perfectly set BEFORE you re set one of your butterflies to meet the other one.

Your engine should idle at equal speed left to right when the bike is run on one cylinder at a time. Remember to carefully ground the inactive plug when running the bike on one cylinder. Take care if you don't understand what is in play here.

Remember.........if the butterflies are exactly right......you can close both of the air bypass screws tight and still get perfect idle and perfect off idle balance response. Set them both to 1 full turn out however once you find the problem.

Ummm, I believe these cables are teflon lined and are not supposed to be lubed. If so and you lube them, they will likely bind

Thanks wood-d. But it can help a 1952 BSA!

All good thoughts from Dr. Curve - except the part about running on one cylinder. Not only are you not under load, you are not even on the "map" of the ECU. Perhaps the one-cylinder method had some value long ago, but it makes the engine run in an undefined state if there's EFI or even a CV carb. Balance with dual vacuum gauges, maybe a Unisyn, or, yuck, a TwinMax and that tells you about balance.

Dr. Curve is clear in saying not to use that method unless you also understand you can smite the high-tension network dead (or mysteriously leaky afterwards) if something slips.

And a '56 Matchless G11 ;)

Sorry Boybiker, you are incorrect. If the problem is indeed as stated in the first post........a primary balance between both cylinders is the basic point to start from and each cylinder must start from point zero equally. Forget the other ECU or map talk until you get the most important things figured out. Have you synchronized your butterflys lately? If not, do that before you hook up any thing under load. Even with your twin max telling you are synced........you still may not be getting a even charge into each cylinder off idle because the air by pass masks quite well. BMW oilheads respond to this tuning just like their brothers of 30 years ago did......

Find the source before you worry about riding around with hook ups on.

Actually, I don't think "running on one cylinder tuning" worked any better 30 years ago. I may have almost convinced Snowbum of that; he uses the "screwdriver shorting" method which I think is better than your "pull the wires" method because you can both listen to each side and switch sides faster while with your method, you sure had better stop the engine before playing with the wires. (OK, you should wear your rubber boots when doing the screwdriver method - that's a downside.) Don't ask me how you compare the sound of one cylinder with the old, fading memory of the other cylinder two minutes ago.

The vacuum port is downstream from both the BBS and the butterfly. There is no way to avoid reading a mix of both with your tuning and or with funny "3000 rpm in my driveway" tuning. Screwing in the BBS, as you suggest, just means starting from zero again.

I am also puzzled when you say, "well, then just open the BBS one turn" as if that's the end of idle tuning. Far from it unless you like bad idling.

Tuning under load gets around it because only the butterflies matter much once you are under load.

But you neglected to mention the real problem with one cylinder running: being off the alpha-n ECU maps (both fuel and spark) and that is an issue for the 3000-rpm-in-driveway method too. There's no sense of tuning when the ECU is screaming back at you, "What the devil are you asking me to do?" Worse yet if you have an FRK in there which really confuses the ECU even more.

The subject of zero=zero has come up from time to time. I guess I think if you are having issues and know how to synch, then your only problem is at idle where, as you say, the BBS can interact with the butterflies to confuse things if the idle stops are wrong. With tuning under load, the butterflies always end up OK, whatever the idle stop screw is set for... but that doesn't help idle and off-idle.

If I may speculate, since I am negative about anybody doing a zero=zero as precisely as really needed, I'd say mail your TBs to Bosch during the winter for a proper indexing and a dab of paint on the screw. I suspect there are a lot of mis-adjusted idle stops out there by now.

We are not on the same page. I also have been 1970 to 2009 non-stop on BMW boxers. I do not tune like you. To each their own.

Thanks for the heads up on the cable lube wood-d.
After reading a lot last night it would seem I did a booboo.I'm lucky in that I use teflon lube and I do it once a month.New cables that are lined... NO LUBE:D

oh. my. Now you're calling the Twinmax an inaccurate hunk of junk too? Holy $4!t batman, now I've heard everything out of your mouth and I've NEVER been one to disparage your ramblings because with your fancy talk, maybe I thought you knew better somehow.

Well, shiver me timbers.

Arrrrrgh

And please get this back on a civil track. A guy who comes in and posts junk-science all the time doesn't get to call one of the civil board members out like that and tell him to "at least try and be right". Pot/Kettle stuff. Get back to tech and we can keep the thread going.

here's my tech addition: I feel that 3k RPMs doesn't accurately enough tune for our actual usage. I notice mine sits more near 4k and has a slight thrum. I'm going to try to re-tune with my uber-inaccurate TwinMax this weekend if the weather doesn't turn foul again.

I believe a twin-max is dead on unless you have dropped it or something. However, at idle, and just as you come off of it.............the air bypass screws can be set to show even intake on the twin-max but the cylinder filling not be even. If you don't understand that I can't help it. I have done this job multiple times, most often in a effort to get perfect idle and very even transition off of it. Why are you ErricZ so upset. I never said a twin max is anything. I use the factory BMW "Moby Dict" unit when doing my bikes and any others I may work on. The original post states that someone is having trouble with their sync side to side...........I am offering a place to start from and suggested how to check for air-leaks with tracers........no body else did that. I understand Roger's problem with anything I say but I am sorry you have jumped to such a conclusion. Bikerboy and I are not on the same page. That is all. Don't make anymore out of it. I can tune a BMW twin so that it will FFR.........but if others think they have better ways........so be it.

I never told anyone to "at least try and be right" in this thread nor do I give a S whether they try my suggestion to tune from "a better starting point" or not, I am just offering information that I know works. Isn't that what this forum is about? My suggestion to you Eric is to set your bike up perfectly with your Twin-Max at load, at whatever RPM you deem best............and then, once you are satisfied........see how your bike runs at idle, one cylinder at a time. Then let us know why you think one side turns out to be so different in RPM from the other. Perhaps then you and bikerboy will understand the importance of getting the butterflies correct if ultra smooth idle and just off idle acceleration is something you desire.

Hey Jim

I'm not sure Eric or I are on your case on this one. Your comment about me having a problem with anything you say is of course stupid, as I've often agreed with you, but in any event, in this case, I think I (and Eric) are pro TwinMax, and are also not of the same page as the boy.

OK, I reread what Jim wrote. Seems clear he thought I was referring to him (try and at least be right) when I was (more or less) quoting boy, not doctor.

We're OK here Jim (except for the dumb, and wrong: " I understand Roger's problem with anything I say")

I used my TwinMax at the 6K service for the first time.
I thought the bike idled fine but the Max showed a little off-adjusted at idle then checked at 4,000 RPM, made a little adjustment there, rechecked idle and went for perfect sync at 4,000 and near perfect at idle.
Bike runs great and idles smooth, for an opposed twin at 1,000-1,100 RPM on the gauge. I'm happy. The TwinMax was easy to use and my bike been running great with 8885 on the clock.

Sorry Roger. I apologize for any perceived insinuation. Glad I was wrong here because lately I have been agreeing more with you and others and trying not to be so vehement. Bikerboy and I are simply not on the same planet however. Sorry to Eric as well. MY BAD!

No worries Jim,

It sometimes happens due to history, even if we ought not let it.
It bugs me much less than it used to, because frankly, racing and the bike biz and always learning more, keep me pretty busy, so I don't have as much time to keep keep Ben from confusing people. I have to prioritize my (fortunately many) actual paying customers, and worry about the benboys of the world less. There is REAL work to be done off board.

Another planet indeed. ;)

Yes, no worries -- I just read it and assumed you have blocked bikerboy posts!

I love my TwinMax!

I love twins!

By the way, Roger, OT:

Bearden and Bedini...I want to see what a genuine EE thinks of some of those equasions. They're beyond me, but the schematics and the results I'm starting to get speak for themselves..

I looked at it Jony. I'm skeptical, but the math was beyond me. But there is plenty math that is beyond me that is valid, so that alone sure doesn't discredit it.

we all know you mean this kind of twin:
http://www.contactdi.com/random/tpx017.jpg

Twins yes - but...
 

Folks there is no way a twinmax can be as useful as a pair of vacuum guages.
the twinmax uses vacuum gauges then electronics so you are seeing a mediated output! It is not showing objective SI units on either side!

Just attach two real vaccum gauges (check that they read the same by sucking on both through a "T" piece).

First do valce clearances , airfilter and plugs to give it a chance to suck properly!
then tickover (dont overheat the engine ) and regular throttle blipping gives a reasonable reading.

If you want to be anally retentive the only real way of doing this is to ride around with them attached - but that is ott for me!!!!

So let me get this straight. An inherently balanced modern semiconductor transducer and an electromagnetic gauge, that is zeroable, is less accurate than some old tubing, and springs and needles and diaphragms, that are completely independent, and in no way track? Not where I come from, and not from where to many engineers or mechanics would sit.

And who cares if they're SI units, (or SAE or whitworthless or left-handed-foot-rupees-per-radian). One tunes for balance, not some target vacuum.

Mediation is not bad. We use signals and sensors and conditioning and amplification, all the time. If it didn't work, we wouldn't be typing this on the interweb. Try THAT with SI-united mechanical gauges. Throughput will be slow.

Where's my typewriter? Where are those twins?!? :p

Thanks, icjohnny347.

Pity this discussion isn't limited to those who have tried dual vacuum gauges.

There are a couple of analogies that come to mind in comparing working with a TwinMax versus dual vacuum gauges. Maybe the most revealing is that the MoDiTec used by real BMW shops shows the two vacuums, it just doesn't go "click" when you get somewhere like a clicker torque wrench. That way the factory-trained techie can see what is going on in both the intake tracks, not just whether they are kind of close in vacuum on an unknown scale, as icjohnny347 correctly points out.

I wish some people would go to my website and think about my points. And then try it. Cheap.

Yes, maybe I am an armchair theorist, as Roger often insists. But my "armchair" includes 48 yrs of bike rebuilding and late nights tuning multiple carbs and FI on my Jag, Alfa, Lotus, and Maserati cars, thank you very much.