<VV> RE:Carb Vents

[grant young]

I have probably seen just about every situation with carb base vents (have
rebuilt over 4000 HV carbs now). Some have swollen and some have shrunk and
hardened (much like their owners :-). I suspect that the swelling is due to
spraying carb cleaner on the exterior of the carb (which is a no-no), or
that they are affected by some engine cleaners (most of which say not to
spray them on plastic or rubber). Some fuel leakage around the carb shaft
might also affect the rubber seals. The most likely cause, however, is that
they are subjected to severe heat changes. They are also flexed every time
the throttle is closed and could therefore loosen over time. And, there is
no way to tighten them on the car, which might be why GM used a sort of
self-tapping screw to install them. I always replace the screws with new
ones on rebuilds, just in case. Hope this helps,
The Carbmeister

<Both of my vents were sitting at an angle on the edge of the plastic
insulator under the carb. It seems the insulator is wider than the carb
base and the vent is too big and
gets caught on the edge of the insulator. I took the vents off and snipped
a flat on the vent with side cutters so it would seat against the carb
properly. Don't know how much dirt I've sucked thru there but any is too
much. Check yours!>
Clark Hartzel