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Old 10-01-2007 | 12:56 AM
  #35  
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Flyboy Dave
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Joined: Mar 2002
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From: Pinon Hills, CA
Default RE: Pump with non-pump carb

....relax, DarZeelon....

The idle "range" is the portion of the lower speed of the engine that is "controlled" by the
low speed needle...the taper of the needle being the controlling part.

The "idle range", which you continually argue does not exist:

'Idle range'? there is no such thing.
....is the "range" controlled by the taper of the LS needle. This "range" is quite small. It exists
from zero throttle opening (no air entering the engine) to about 1/8 throttle opening, certainly
no more than 1/4 throttle....probably not even that much. Keep in mind, as the throttle barrel
opens, it is moving away from the LS needle.

The taper on the LS needle works the same way as the taper on the high speed needle. As the
LS needle runs out of it's "range"....the taper of the HS needle is already allowing more fuel into
the spraybar. The difference between these two functions is known as the "transition". This
function is not accomplished by accident. When all things are well, the transition from the
LS, to the HS is not noticeable. This is what carb tuning is all about. The carb myth about the LS
needle comes in right here.

To be continued.