If the engine "ran fine when you got it" with that 'B' then what
do you suppose happened to the throttle body while it was
sitting, Maybe the mice got to it and chowed out the bore for
the shaft or erosion of some sort??????
Unless that throttle shaft is REALLY loose, that carb should run
just fine if it did before, might be a tiny bit rough at idle
if it's worn a lot, but still should be near normal. Put a few
dabs of grease around the shaft to seal it up and see if it
will idle ok and if the "hiss" goes away.
I think you have other problems.
Denny G
