Funny I have never managed to have any luck with a manometer on my guzzi’s
I balanced the t5 using gauges and then tried the manometer and it suck the ATF fluid straight into the engine
Refitted gauges and all ok 
That’s because it is more sensitive than your gauges, you need to turn the engine off before it sucks up the fluid
Actually as its more accurate than the gauges, your gauges can’t be very good, I tend to use the manometer, even though I have a carb tune
Knowing my luck that would happen to me too!
There are two ways to prevent that, apart from quick reflexes. Have long tubes, so you have time to turn the engine off, or put a bottle in each leg, giving a reservoir to collect the fluid.If it does suck the fluid into the manifold it does prove that the carbs/injector butterflies are way out of balance.I actually use a TwinMax now, the electronic version of the manometer, which is probably the next most accurate one.
I think the Carbtune is probably best for me then I’m sure I’d have an engine full of water and that wouldn’t do it any good! And I just re read it again and it says 20/25ft of tube - too much spaghetti!
With the manometers what I use is like a tiny G clamp get them from shops taht sell tropical fish they are used to regulate air flow from the air pump it slows the flow so you get less "wobble and steadies the water or mercury much less chance of it flowing back as the ol Guzzis DO suck …alot …lol bit of lateral thinking is all.
Jmee, you should have considered the Twinmax. Easier to use and more accurate than the carbtune on a twin.
And the Manometer you can make in 10 minutes, costing all of £5. Fill with ATF or light oil. Mine has about 5 metres of tube max. 100% reliable, 100% accurate, no setting up, just plug in and use.I even made my own connectors for the manifolds, just drill down the centre of a 6mm bolt and cut the head off. The smaller the hole the better.
Brian UK2013-08-03 08:54:56
Bear in mind that the accuracy of the settings: A. lasts until the next time your cables are disturbed / moved / stretched; B. ceases to have effect once the slides are raised beyond the point where it matters.
I use a “carb balancer” sold on e-Bay by Julian Ridsdill. It works really well. I would love to buy a pair of Davida gauges but until then Julian’s little gadget gets the job done very satisfactorily. It has two ball bearings running in rings made of clear plastic tubing. One ring is sealed, the ball bearing in this tube just tells you where gravimetric centre is. The other ring has ends connected via plastic orifice tubes to your inlet manifolds with matching threads and small O rings. When the bike is running the ball bearing in this ring moves from side to side as each cylinder sucks in. It is very easy to set your cylinders to give equal work by adjusting the idle speed screws and then adjust the throttle cable lengths to give equal draw as the throttle is gently cracked open.
All the best,
David,CylvaBirch2013-08-04 18:16:22