What's a good carb sync tool (not looking for homemade this time)

Discussion in 'The Garage' started by LuciferMutt, Mar 18, 2009.

  1. LuciferMutt

    LuciferMutt Rides slow bike slow

    Joined:
    Aug 19, 2008
    Oddometer:
    13,136
    Location:
    New(er) Mexico
    What's a good carb sync tool for bikes with two cylinders? (parallel twin in my case).

    Right now I'm using the two bottle contraption with the hose that connects the two bottles so nothing can get sucked into the carb. I hate using it; I can't ever tell if the fluid is really flowing one way or the other until the carbs are WAY off. I just can't get good adjustments with it. I had to do my second sync with this tool last night and I do beleive I made it worse... :eek1 But I had to ride in this morning since my wife couldn't carpool with me and my bike can park at work -- car can't. The bike is running good except for an off-idle stumble/hesitation that was there the last time the carbs were out of sync.

    Anyway, I'm giving up on all the homemade tubes and fluid crap. I want something digital or with gauges. I've heard electronic sync tools (twinmax?) are quite good but wanted to see if anyone has used one. Suggestions? :ear
    #1
  2. yosmitetom

    yosmitetom Banned

    Joined:
    Jun 7, 2008
    Oddometer:
    3,354
    Location:
    East Texas
    Morgan Carbtune is what I use.

    <a href="http://www.carbtune.com/">Carbtune
    #2
  3. showkey

    showkey Long timer

    Joined:
    Jun 25, 2007
    Oddometer:
    2,114
    Location:
    Wausau
    +10 carbtune:norton
    #3
  4. fritzcoinc

    fritzcoinc Enjoying my last V8

    Joined:
    Apr 30, 2008
    Oddometer:
    8,757
    Location:
    Hockley, Tx
    Although home made this works well. I use two dial vac. gages. These are the type that can be adjusted. Before starting to sync. I connect both to the same vac source and adjust to read the same if needed. The gages are mounted in a pc. of shipping foam one on top of the other slightly offset so it is EZ to see both needles at the same time.

    Another important part of carb. syn. is to set the idel throttle opening of each carb. the same. This is so that each throttle will open from the same point. This will insure that the different fuel flow circuts in the carb. start at the same time during throttle opening. I use a 2" dial indicator to measure the height of the slide in the carb. bore. Something different may be needed for butterflies.

    Hopfully you did the sync. at some RPM that stablized the fluid columns and you could see the difference. The same hold true for most sync. tools.
    For my Guzzi 4000 RPM is the point the needles stablize.

    Pic comming.
    Here it is:
    [​IMG]
    #4
  5. duck

    duck Banned

    Joined:
    Mar 19, 2004
    Oddometer:
    10,403
    Location:
    Seattle (Berkeley with rain)
    TwinMax - not as fancy or 99.999999999999999999% accurate but easy and quick.
    #5
  6. bwringer

    bwringer Gimpy, Yet Alacritous

    Joined:
    Jan 22, 2008
    Oddometer:
    2,565
    Location:
    Indianapolis
    Morgan Carbtune. +10,000
    #6
  7. pilot3

    pilot3 Been here awhile

    Joined:
    Aug 28, 2008
    Oddometer:
    522
    What he said
    #7
  8. FuriousGeorge

    FuriousGeorge Been here awhile

    Joined:
    Dec 22, 2005
    Oddometer:
    102
    Location:
    Turner, OR
    One more vote for the carbtune. Simple and works great. So nice not having to worry about spilling any fluids. Just get the four cylinder version. The two cylinder version isn't much cheaper and you never know what you'll be working on in the future.
    #8
  9. johnjen

    johnjen Now, even more NOW!…

    Joined:
    Nov 28, 2001
    Oddometer:
    16,915
    The reason I like the TwinMax is because it is a differential gauge. It is an inexpensive (relatively speaking) tool that is portable and can be used in 'real world' testing.

    And as is usually the case you get what you pay for. And any tool can be damaged due to abuse (being dropped for instance) so in the end it is about how much accurracy and reliability are you willing to pay for.

    JJ
    #9
  10. mtrhd101

    mtrhd101 Garage Queen lover

    Joined:
    Feb 6, 2007
    Oddometer:
    381
    Location:
    Texarkana
    The newer Motion Pro works pretty good and no mercury.. Has adjustment for balance to sync before use..
    #10
  11. 2slow

    2slow Road toad

    Joined:
    Jun 25, 2007
    Oddometer:
    456
    Location:
    Stafford, VA
    I'm using a flowmeter. Easier, cheaper, and quicker than vacuum gauges. Just stuff it in the inlet tract, either in the carb/throttle body or air horn and proceed. It is not as precise a method as a good vacuum setup but I find the results adequate.

    http://www.cbperformance.com/catalog.asp?ProductID=572
    #11
  12. Lomax

    Lomax Nanu-Nanu Adventurer

    Joined:
    Jul 15, 2004
    Oddometer:
    10,246
    Location:
    Westminster Colorado
    I will put in a vote for the TwinMax. :thumb It is easy to use and I have had great results with it.

    Marc
    #12
  13. hugemoth

    hugemoth Big Brother is watching you!

    Joined:
    Sep 6, 2007
    Oddometer:
    3,886
    Location:
    RESIST!
    My favorite is still the old mercury stick but I don't even know if you can get them any more.

    Q
    #13
  14. bwringer

    bwringer Gimpy, Yet Alacritous

    Joined:
    Jan 22, 2008
    Oddometer:
    2,565
    Location:
    Indianapolis
    Right -- the Carbtune can be used on three and four cylinder bikes as well.

    "Be the center of attraction in your circle of friends! Be the envy of friends and neighbors as they flock around to watch you tear down and tune up all kinds of motorcycles..."
    #14
  15. yosmitetom

    yosmitetom Banned

    Joined:
    Jun 7, 2008
    Oddometer:
    3,354
    Location:
    East Texas
    I think you can still get 'em from China.
    #15
  16. walstib

    walstib DeadHead

    Joined:
    Sep 29, 2005
    Oddometer:
    174
    Location:
    N38º21.828’ W86º01.391’ elev. 891’
    Hey Now,

    Carb Tune, delivered to the U.S. by Royal Mail in 1 week :clap
    #16
  17. fatboy

    fatboy Been here awhile

    Joined:
    Jan 13, 2005
    Oddometer:
    317
    Location:
    Georgetown, Texas
    No contest ... carbtune.
    #17