Tim:
My sense (please, those who REALLY know provide a definitive answer)
from looking over the by-pass valve when installing the gaskets and
valve was that screwing it in (to the right) caused an inner threaded
shaft to move inward toward the valve, thus compressing the spring,
causing a thighter fit and more vacum needed to open the valve, with
the noticible decrease in the idle RPMs when you screw it in.
FYI. My '70 TR6 carbs did not come with the adjustable screw on the
by-pass valve. I had rebuilt my original ones and still had a
leak (may have been the tension on the spring had gone bad). Ended
up swaping the valves from another set of carbs that had the external
adjustment and all is fine in carb land!
Scott Suhring
Elizabethtown, PA
'70 TR6
Tim Gaines wrote:
>
> Scott,
>
> Great info on the bypass valve, but if I remember correctly (probably
> don't) screwing the adjustment screw IN (clockwise) actually reduces
> the spring load on the valve and causes it to open under less pressure.
> Do I have this right? What I really want someone to tell me is how to
> make the adjustment. I have cleaned the assemblies and replaced the
> gaskets in both my Spit and my TR6, but I've just been adjusting by trial
> and error until things "feel" right.
>
> Tim Gaines
> 1980 Spitfire
> 1974 TR6
>
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