TxGoat wrote:
Replacing bushes is not difficult if you have a way to size them after installation, which usually involves reaming. You'd be working with some delicate parts, and wear in things like piovot pins may not be easy to assess. Small springs in the centrifugal advance can stretch or lose tension. If the shaft is very loose, replacing the bushes would no doubt make a significant improvement.

A new shaft, bushes, and springs would be nice, if they can be had.