<VV> Re: LM carbs

[BobHelt at aol.com]

In a message dated 5/3/2006 8:14:37 AM US Mountain Standard Time,  
tonyu at roava.net writes:

I have  several of these carbs 
that I parted out, VAB screw stuck solid and  immovable.   A couple 
others that were stuck, but also in better  shape otherwise, got 
"fixed" by just dobbing the JB Weld over the slot  vents in the air 
bleed, plugged, forgot about it and all was  well.   Idle mixture then 
adjusted like any other carb, seemed  to run better.   I was happy.



Tony and all,
These valves were called Adjustable Part-Throttle (APT) valves by Chevrolet  
and were used in many other carbs besides Corvair AIR carbs. Thes valves were  
set very accurately at the factory to meet emission requirements for off-idle 
 operation and to limit the idle A/F ratios. The factory locked these valves 
in  position because they didn't want anyone readjusting them. That is why you 
are  finding these valves "stuck". These valves are not intended to be 
readjusted  after they left the factory.
Regards,
Bob Helt