Nobody has mentioned what would be my prime suspect: The balance pin hole in the bottom of the key being too tight. You should be able to lift the key an eighth inch or so, and it fall freely. If not, and the key bushing are not too tight, the balance pin hole in the bottom of the key needs to be reamed, mostly on the sides, being careful not to create a front-to-back chucking (pully) key. Frank Emerson
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