Results 1 to 15 of 15

Thread: vacuum guages

  1. #1

    vacuum guages

    Anyone know where decent inexpensive vacuum guages can be had to
    build a carb balancer.

    I gave up on the mercury ones.

    I want to try the meter route.

    Dont have many bucks to spend.

  2. #2
    Don't forget your towel
    Join Date
    Apr 2003
    Location
    Bainbridge Island WA
    Posts
    847
    Those mercury gauges ARE vacuum operated.

    I'm going to guess you are looking at some analog (dial) vacuum gauges instead. Having tried this route many years ago I must say that I never could get the two gauges to agree, I just couldn't get them synchronized- which sort of defeated the purpose. If you can't get the carbs synched with the mercury sticks (and the tubes aren't kinked) then it's time to rule out some underlying defect in the carbs themselves.

    Steve

  3. #3

    vacuum guages

    No,
    I use the mercury vacuum guages and they did work
    but that are too volatile.

    if they fell over I lost the mercury and once
    something went wrong and some mercury got sucked into the carb. NOT GOOD,

    I want something simpler and not so delicate.

    I am just looking for 2 decent inexpensive vacuum guages. (two of the same manufacturer and model, that I can use instead.

    It's funny. I searched the internet and ebay and there are very few vacuum guages available.

    At least ones that are affordable.

    Gerry

  4. #4

  5. #5
    Rally Rat bprigge's Avatar
    Join Date
    Nov 2004
    Location
    North Branch Minnesota
    Posts
    124
    Don't forget the restrictors or the needles will flutter to the point where you
    can't make out what they are saying.

    Also, I had a Suzuku 750 water buffalo suck all the mercury up when I flared the throttle with the carb styx hooked up.

    I've had best results by syncing my Beemer carbs with the 'ground a spark
    pug wire' method. I sync then at idle and then again at 2500 'ungrounded'
    RPM. Definetely want to have a HOT engine and valves adjusted first.

    Bruce

  6. #6
    James.A
    Guest
    I bought a used "Twin-max" recently on IBMWR. Used it for the first time today based on the lesson ManicMechanic gave me at the Solstice Ride. All I can say is "WOW, what a difference." I got mine for $80, and I've seen 'em cheaper yet. My 750(FIB)went from acting like it was starved for fuel to "it's all here in my hand". Good product, forget about mercury, or any other pure vacuum device.

  7. #7
    Rally Rat bprigge's Avatar
    Join Date
    Nov 2004
    Location
    North Branch Minnesota
    Posts
    124
    How does the 'Twin Max' work? You already said it works good, but how do you use it?? What it be like??? Bruce

  8. #8
    James.A
    Guest
    The TwinMax has a right/left meter that indicates a vacuum imbalance. It has 2 hoses that attach to vacuum ports on the carbs. Both my bikes have ports on the carbs. they are located on the outboard sides near the heads. Some Bing carbs have ports on the underside near the idle jet screws. ManicMechanic told me that in the absence of ports, you could tap the intake rubber sleeves between the carb and the heads with insulin needles. The "TwinMax" shows imbalance by the meter needle pulling right or left when the motor is running. There is a large protocol to follow, but it works pretty much like vacuum gauges.

  9. #9
    Rally Rat bprigge's Avatar
    Join Date
    Nov 2004
    Location
    North Branch Minnesota
    Posts
    124
    I'm tempted to buy one, what with always being concerned with optimum carb balance. Incidently I pulled my left head Sunday night to send it off for a hardened seat job and the left exhaust valve was eroded away over about 10% of its circumference. I blew in the exhaust spigot with my mouth to see
    how much air would leak past and it was a considerable amount. The bike ran
    strong and idled OK after a good warm up with the same idle balance settings
    it had before the valve burn. Makes me think a guy should do a compression check when buying an airhead, even if the bike runs well. I've seen 4 cylinder
    engines run very poorly with a valve burnt like mine was. Bruce

  10. #10
    Rbike
    Guest
    You can build your own carb synchronizer with a yard stick (or any stick), some clear vinyl tubing, a little electrical tape, and some automatic transmission fluid...all together shouldn't cost more than $5.

    I don't know exactly how much tubing you need exactly but I figure that about 20 feet will work. Match the sizing to the ports on the underside of the carbs...maybe 3/16". The center of the tubing goes at the bottom of the yardstick. Then each tube runs up each side of the yardstick and is held in place with some electrical tape...looking like your old mercury sticks. Pour enough fluid in the tubing to fill up each side to about the three inch mark on the yardstick, that isn't much fluid. It will take a while for the fluid to settle so it is best to pour it in the night before you want to use it.

    You can use this just like the mercury sticks but it will read slower. The length of tubing acts like a damper and the trany fluid is much heavier that the mercury so it doesn't bounce as much.

    This was thought up by Hugh Kenny of WY...I thought he sent it in to one of the Airmails. Look around and there should be some plans for it in one of the issues.

    ************************************************** ***
    If you still want to use cheap vacuum guages...you'll need to be sure they are calibrated and that won't be cheap. You are looking for a very light difference that may not show up with cheap uncalibrated guages. I'll stick with mercury.

  11. #11
    Stressed Member jmerlino's Avatar
    Join Date
    Jul 2004
    Location
    Boston, MA
    Posts
    879
    Quote Originally Posted by Rbike
    This was thought up by Hugh Kenny of WY...I thought he sent it in to one of the Airmails. Look around and there should be some plans for it in one of the issues.
    Linky.
    --Joe Merlino - Modified '82 R100RT

  12. #12
    leave my monkey alone LORAZEPAM's Avatar
    Join Date
    Jun 2003
    Location
    West Salem, OH
    Posts
    2,888
    Quote Originally Posted by bprigge
    How does the 'Twin Max' work? You already said it works good, but how do you use it?? What it be like??? Bruce
    The twinmax is the best thing for balancing carbs and tb there is period.
    If you can turn it on and follow simple directions, it balances them as good as any mechanic in the world can do. Heck , most of them would probably be using the twinmax anyway
    Gale Smith
    2009 Versys
    1999 R1100RT

  13. #13
    Registered User lkchris's Avatar
    Join Date
    Mar 2003
    Location
    Albuquerque, NM
    Posts
    6,212
    Quote Originally Posted by lorazepam
    The twinmax is the best thing for balancing carbs and tb there is period.
    Actually the Walus meter is, but it's out of production.

    Unlike Twinmax needle never bounces.

    Dial is 4-in diameter.

    Walus was Chicago BMW club member.
    Kent Christensen
    21482
    '12 R1200RT, '02 R1100S, '84 R80G/S

  14. #14
    leave my monkey alone LORAZEPAM's Avatar
    Join Date
    Jun 2003
    Location
    West Salem, OH
    Posts
    2,888
    Quote Originally Posted by lkchris
    Actually the Walus meter is, but it's out of production.

    Unlike Twinmax needle never bounces.

    Dial is 4-in diameter.

    Walus was Chicago BMW club member.
    Ok the best unit currently in production.....
    Gale Smith
    2009 Versys
    1999 R1100RT

  15. #15
    Rbike
    Guest
    Two more things...

    Building the $5 sychronizer is actually a differential guage. And because of the tubing lengths you need to be patient when making changes. It takes some time for the changes to show completely.

    Also...as far as balancing an engine...I could do a much better job if I could outfit these engines with a port going into the combustion chamber. You can then connect a high temp pressure transducer to the port and use crankshaft rotation as a time base to display the firing pressure pattern. From that you can determine how well the cylinder is working and how much load it is carrying. What we are doing is simply synchronizing the throttle shaft movements and hoping that it will actually balance the engine.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •