[Spridgets] Twin Carbs Tip

[David Lieb]

>       yeah, they measure different things, but you there is only ONE
>       screw to turn! !!!  ???
> 
>       what am i missing, or is that why the back and forth and back
>       and forth until it ALL comes together?

Not true.
There is only one mixture adjustment per carb, but that has little to do
with the balance. Balance is set by loosening the linkage joining the carbs
and then using the idle stop screws to get the air-flow the same prior to
tightening the linkage back down and testing it again at about 2500rpm.
Be careful when tightening the linkage not to allow too much slop or
off-centeredness(?) of the shaft betweeen the carbs. 

The balance is attempting to synchronize the two
throttle butterflies so that they are opening in unison (none of that 
"progressive 4-barrel" nonsense here!). The problem is that we cannot 
simply look down the throat of the carb and actually measure the throttle 
opening, all we can do is measure the amount of air-flow at each carb 
and compare them. Unfortunately, the air-flow is affected by how 
efficiently the engine is running, which is impacted by the mixture, so, if
one carb's mixture is spot-on and the other one isn't, balancing the flow
at that moment does NOT synchronize the butterflies. Likewise, if you
do get the flow balanced at that point and then get the mixtures both
spot-on, the flow will have changed. Just consider yourself fortunate
that the ignition timing is not set on a per-cylinder basis! Although I 
suppose I should point out that your timing and valve lash should have 
been set properly before you started the carbs...
David Lieb