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Thread: Best TB sync tool?

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  1. #1
    JohnWC
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    Best TB sync tool?

    I have a "Twinmax Carburettor Balancer" that I used on my R1100. It is, as most of you know, "electronic". The balancing went okay, and it certainly improved the vibration levels on the engine, both at idle and running down the road. But it still seems like it could be smoother at around 4000 rpm and up. I am usually running it at about 3000 since it seems to prefer that level. What is the feeling on the TB sync tool that will do the best, most accurate job? I'm wondering if "electronics" can take the place of a more mechanical design model. Or is the Twinmax as good as you can get? Thanks.

  2. #2
    Benchwrenching PGlaves's Avatar
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    Precision glass tubing with mercury columns are the gold standard for accuracy. As laboratory instruments that is what is used to calibrate precision vacuum measuring devices.

    Given the hazardous nature of mercury they are no longer favored as mechanical workshop test equipment. I still have a set though.

    Twin Max, Carbtune, and others are now favored. I have no idea which of these is the most precise. I have an old Twinmax that works fine and is sufficient.

    Frankly, I don't know what I would buy if I didn't already have what I have.

    Variations in vacuum and actual inlet airflow due to valve adjustment, deposits in the intake path, and other causes is likely to be a bigger factor than the accuracy of either a Twinmax, or Carbtune, or whatever.

    Finally, Airheads and Oilheads will have a buzzy spot. Period. It is due to the fore-aft offset of the two pistons, rods, and counterweights. There will at some rpm always be a rocking couple imbalance. Frequently it is around 4,000 to 4,200 rpm. Perfect carb synchronization won't make it go away.
    Last edited by PGlaves; 12-07-2012 at 02:12 PM.
    Paul Glaves - "Big Bend", Texas U.S.A
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  3. #3
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    The key to a smooth engine starts with precise valve adjustment, then synch. As far as tools, as a lab guy for my career I've had access to all manner of gauges from mecury types to precision manometers, etc etc. But I use my older TwinMax for bikes.
    Some would say the Harmonizer may be the best of the current electronic tools- it has more features (see the relevant thread on advrider).

    However, you're never get an 1100 dead smooth across the rev band for reasons Paul notes. I regularly service a couple 1100s including the SOs R1100S and they aren't nearly as smooth as a hexhead or camhead due to basic design differences.
    The 4 cyl bikes are smoother yet but even though I ride both a K1200RS and a K1200GT (wedge motor), I like the engine character of the R bikes. The K-GT has the least satisfying engine character of that set despite its power- its a "whiner", making a whole series of unappealing sounds from its gearbox. The 1200 brick is much nicer to hear and feel..

  4. #4
    Riding where it's hot! AZ-J's Avatar
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    I have the TwinMax and it is good. I wanted the Harmonizer but cannot locate a new one. Are there any?
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    Jordan M, MOA #24434
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  5. #5
    rabid reader dbrick's Avatar
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    Quote Originally Posted by AZ-J View Post
    I have the TwinMax and it is good. I wanted the Harmonizer but cannot locate a new one. Are there any?
    I think so. In this thread: http://advrider.com/forums/showthrea...701625&page=49
    see post #732 and after.
    David Brick
    Santa Cruz CA
    2007 R1200R

  6. #6
    JohnWC
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    However, you're never get an 1100 dead smooth across the rev band for reasons Paul notes. I regularly service a couple 1100s including the SOs R1100S and they aren't nearly as smooth as a hexhead or camhead due to basic design differences.
    ... The 1200 brick is much nicer to hear and feel..[/QUOTE]

    Excellent information to know. I keep reading about how people have these dead smooth engines, and I think, " What's wrong with mine?" Now I know there isn't anything wrong with it. And I can also stop tinkering with it to get it better. I set the valves, did the sync, changed the plugs, etc. It won't change. It seems like for better or worse, the oilheads are the worst on vibration, probably worse than even the R100 airheads are. I really like the basic design of the bike. I will live with the vibration level now that I know it is inherent in the engine.

    I am curious, though, how BMW changed the engine in the later models to lower the vibrations.

  7. #7
    Registered User mneblett's Avatar
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    Quote Originally Posted by JConway607 View Post
    I am curious, though, how BMW changed the engine in the later models to lower the vibrations.
    A counter balancer added to the rear end of the auxilliary shaft driving the oil pumps and cam chains.
    Mark Neblett
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  8. #8
    JohnWC
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    Quote Originally Posted by mneblett View Post
    A counter balancer added to the rear end of the auxilliary shaft driving the oil pumps and cam chains.
    What model and year did BMW go with those changes?

  9. #9
    Riding where it's hot! AZ-J's Avatar
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    I ordered the Harmonizer via PayPal. Anyone want to buy a hardly used TwinMax?
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    Jordan M, MOA #24434
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  10. #10
    Registered User twinsig's Avatar
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    Found the vibration moves around some. My current state of tune smooths out the vibes at 3500 (70 mph in 6th). And the kind officer reminded me of that last night while traveling through a 55 zone.
    He let me go with a verbal warning (and watch out for the deer), i wished him a merry Christmas.
    I wonder. If been on one of those LOUD twins would he have done the same?
    Democracy is two wolves and a lamb voting on what to have for lunch
    Liberty is a well-armed lamb contesting the vote

  11. #11
    Registered User JoshuaTree's Avatar
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    Lightbulb For those of us with uncertain gravitic anomalies in the garage...

    (i.e. I drop 'stuff' sometimes)

    I wound up with a refurbished Kowa Tools KEK-55 (the original version, with the vacuum tube ports on the back of the unit). It's done a credible job so far (now 10+ years), and usually checks close enough to the factory BMW Synchro.
    Josh Friedman
    "Quis custodiet ipsos custodes?"
    "... Love Much, Laugh Often..."

  12. #12
    the Wizard of Oz 26667's Avatar
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    slightly off topic, sorry

    Quote Originally Posted by PGlaves View Post
    P

    There will at some rpm always be a rocking couple imbalance. Frequently it is around 4,000 to 4,200 rpm. Perfect carb synchronization won't make it go away.
    Interesting, Paul. After a number of years of riding my '82 R100, i "discovered"that there was a real sweet spot right at 4200. I've kept thinking there was something out of whack because my 2000 R1100RT wouldn't do the same, and was, in fact, rough at 4000-4200.
    We might as well walk. ~ Adam Guettel The Light In The Piazza
    used to own: 1982 R100T, 1984 R65, 1986K75C, 1997 R1100RT, R850R, K75S, 1978 R100RS... what was I thinking?

  13. #13
    MOA #148075, BMWRO Shaun09's Avatar
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    The first post in the Harmonizer thread on ADVrider is where you make a purchase using PayPal. The supply problem seems to be fixed. I picked one up when they returned to market, but I have to wait until X-mas to "officially" play with it. Cheers!
    Chris

    2009 BMW R1200RT (Shaun), 2004 MINI Cooper S (Gromit), 2006 BMW X3 (Wallace)

  14. #14
    Registered User roger 04 rt's Avatar
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    Quote Originally Posted by dbrick View Post
    I think so. In this thread: http://advrider.com/forums/showthrea...701625&page=49
    see post #732 and after.
    Quote Originally Posted by Shaun09 View Post
    The first post in the Harmonizer thread on ADVrider is where you make a purchase using PayPal. The supply problem seems to be fixed. I picked one up when they returned to market, but I have to wait until X-mas to "officially" play with it. Cheers!
    Thank you both for posting this updated information. It seemed like he had had to shut down for a while. It looks like quite a good, modern unit.

  15. #15
    Registered User PAS's Avatar
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    I have both the merc stix and the harmonizer. The harmonizer is nice since I dont have to hang it to use it or store it. Nicely designed and built.

    PAS
    81 R100RT
    03 R1150RT

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