K&B with Perry carb. too rich
#26
The following discussion is for the old style carburetor. The medium (.40) size, and large (.60) size carbs use the same needle valve which is approximately .95" long. The small carb needle has the same threads, but is approximately .85" long, and the same thread as the larger needles. Sounds like you might have the wrong needle in your older style carb too?