[AT] Small Zenith carb (CA) question please

[John Wilkens]

The CA is running rich--blowing black smoke.  I put two sizes smaller main 
jet in (.24) and set the float level a little lower (float valve is not 
leaking) and it still smokes and fouls plugs.      Then I put a Zenith carb 
from a Wisconsin engine on it (same size main jet) and it runs fine--no 
black smoke--but the linkage is all wrong for use on the 
CA.       So.........does anyone have a clue as to what might be wrong with 
the original carb??  Could someone have drilled some passage way out inside 
and messed it up??    If you know of a small carb expert I might contact 
with this question please let me know.     John Wilkens

                    In the wide-open spaces of NE Oregon