To get the manometer to work, one side of the U is open to the atmosphere, the other goes into the mouth of the carb. For all the trouble they are to make, I know of a few workshops (obviously this is going back some years, there aren't too many people now who are massively into carbs as mechanics) who had the 'right' equipment, but used the 'hose in the ear trick' because it was actually better.

thanks jmac..i'll need to clean up my ears for a perfect pitch to make it in sync

get 2 tubes, one for each ear/carb, listen in stereo.

great tips there in stereo will be much better to make the comparison..thanks 1000Coupe

Be careful with that, I might be the odd one out, but when I tried that, the same carb sounded different in each ear, so I have to use one hose and swap from one carb to the other. I must have damage (or more damage) to one ear different to the other ear or something. That's not unusual, anything from firing a rifle, to workshop noise where the machines are on one side of the workshop can do it.

I have used a manometer (my old plumbing one)to balance my su's, to get it to work I had a piece of plastic that coved the ram tube then drilled one hole to fit the manometer tube into and then drilled a some small ones to let the carb get some air.

Place the plastic over the intake and adjust be drilling more holes or taping the holes up so the engine runs well and you can see the preasure reading.

I balanced it with my ears first then checked it with the manometer.

thank you very much guys for the great tips and methods!

now i know when to use the mano & my ears

thanks.