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.