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Thread: Best TB sync tool?

  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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  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
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  6. #6
    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)

  7. #7
    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.

  8. #8
    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
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  9. #9
    Registered User twinsig's Avatar
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    vacuum guages?

    what about a couple of vac guages?
    anyone tried that, maybe with restricting/jetting the hoses?
    Democracy is two wolves and a lamb voting on what to have for lunch
    Liberty is a well-armed lamb contesting the vote

  10. #10
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    A pair of ordinary full range vacuum gauges are about going to cost you a bit less than a proper tool and not be anywhere even close to the required sensitivity to get a good synch. Gauges of proper range and sensitivity are not cheap and would cost a bunch more than a balance tool. Note that usual balance tools aren't measuring anything and putting a number on it - they only balance on side against another and show any difference- and that's why they're not more expensive. You don't want to know what a pair of precision manometers would cost..

    Its either make stix or buy one of the usual tools.......

  11. #11
    Registered User David13's Avatar
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    Grok, not his real name, started selling Harmonizer again. And quickly sold out. They are well known as real good.
    I don't know if they are back in production and in stock at this time. Or not.
    dc

  12. #12
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    I have a set of Motion Pro mercury sticks that I bought about eight years ago or so when I had a Kawasaki Vulcan 750. I used it to measure the vacuum on my 2011 R1200GS last week, at idle, and at about 1400-1800 rpm. At idle, the differential was well within the allowable specified in my BMW repair CD, and at 1400 to 1800 rpm the differential was essentially zero. So I was done without having to make any adjustments to anything.

    The bike has about 46,000 km on it, and the vacuum has always been checked by a BMW dealer before. I am almost due for an air filter, so I will see if that makes any difference the next time. Also, I checked the valves first, and they were within spec and didn't require any adjustment.

    The engine is running smooth and strong.

    I am hoping that the engine will stay well synched and that, aside from checking the synch, it will never require any actual adjustment.

    Dave McDougall
    2011 R1200GS


  13. #13
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    what about a couple of vac guages?
    No, there is too much needle movement.

  14. #14
    Registered User mneblett's Avatar
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    Quote Originally Posted by twinsig View Post
    what about a couple of vac guages?
    anyone tried that, maybe with restricting/jetting the hoses?
    The Carbtune unit is a vacuum-type device, with metal rods in the four clear tubes. I prefer it over the TwinMax I had (which crapped out), as I find the "analog" information presented by the slighly-bouncing rods to be more useful during adjustments. I have not had to use damping restrictors in the lines (and in fact would prefer not to do so, as the rods wouldn't be a "lively" as I like to see).

    BTW, for those of you who still have mercury sticks, GET RID OF THEM! (proper disposal, of course) Once I looked into whether mercury is as hazardous to health as others were saying it is, I *immediately* got mine out of the garage. Mercury doesn't have a high vapor pressure, but that doesn't mean there aren't consequences from long-term exposure -- let alone the problems that can result from a spill from a tipped-over or broken tube. Ugh.
    Mark Neblett
    Fairfax, VA
    #32806

  15. #15
    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.

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