Isn't the Uni-Syn adjustable. On mine, the center part threads in and
out in order to fine tune the tool which is, in effect, a simple venturi
device. By adjusting it so the opening around the center part is
smallest, the velocity of the air going through the Uni-Syn will be sped
up so that it will raise the float. Too close and the float will go to
the very top of the tube. Too wide and it won't move at all.
Eric
Fred Pixley wrote:
>
> >Date: Sun, 17 Jan 1999 13:33:30 -0800
> >From: "Lawrie Alexander" <Lawrie@britcars.com>
> >Subject: Re: Use of Uni-Syn (was carb. kit)
>
> >The problem with that, Paul, is that you are relying (a) on your ability to
> >turn the idle adjustment screws EXACTLY the same amount, and (b) your
> >expectation that such turning will have the same mechanical effect on the
> >position of the throttle butterfly. Especially when the throttle shafts are
> >worn, the accomplishment of equal adjustments just by eye-balling the
> >position of the adjustment screws is very difficult.
>
> >And my original point was that this lack of accuracy need not be tolerated
> >because the Uni-Syn is, by its very design, just the tool to make such
> >guesswork unnecessary! If you adjust the throttle screws so that the
> >position of the "ball" in the tube is the same on each carburetor, you know
> >for a fact that the air flow through each venturi is the same, n'est-ce
> pas?
>
> Sometimes Paul's method is the most practical. What Lawrie says is correct,
> but on some engines like my Midget 1275's which have twin HS2"s they don't
> draw enough air at idle to raise the floats in the unisyn. Then I raise the
> idle until the unisyn functions and after balancing I reduce the idle
> hopefully an equal amount on each carb. My unisyn is only a couple years
> old. It's possible the older ones were more sensitive. It's still much
> faster and easier than the tube in the ear method which I did before
> purchasing the unisyn.
>
> Fred Pixley
> Napanee, Ontario, Canada
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