<VV> RE: YH Spacing

[grant young]

First, what is the accepted "correct" distance for the separation between
the carb/throttle
body on a YH carb ('63 Spyder)?

The 1963 and all later YH carbs should have a 1/4" TB gasket. There are a
lot of "cheap" or 
generic kits on the market that have a collection of gaskets in them. The
1962 carbs used 1/8" and .046" gaskets stacked together. The Corvette carbs
used the .046" alone, as did most Nash applications. The carbs with the
thinner gaskets also have a shorter (by 1/4") choke connector rod
(l-shaped), including the Corvair carb. This rod is adjusted (bent) to pick
up a very critical .033" clearance at the throttle plate and throttle body
interface when the fast idle link is on the highest step of the choke fast
idle cam. While the rods can physically interchanged (I see it a lot), the
resulting exaggerated shape of the rods can cause binding and improper
operation of the choke system (hard start, flooding, leaking, etc.). I
stopped using the multi-gasket kits long ago as the stacked gaskets will
compress more easily and quickly than the correct single gasket. When that
happens, the carb has to be removed from the engine for a proper
re-adjustment (which all owners know is just not a lot of fun). Hope this
helps.
The Carbmeister