carb rejetting on 78 kz1000

nads.com wrote:

The higher the needle, the larger the main jet opening becomes. Would a larger main not leave a larger opening as well?

The main jet opening doesn't enlarge as the needle rises, because the needle doesn't operate within the main jet orifice.

The main jet screws into bottom of the bleeder tube which screws into the carb body.

The needle operates within the jet located at top of the bleeder tube. As I recall, the jet may be an integral part of the tube or a separate jet pressed into the carb body.

The main jet orifice remains unaffected and unobstructed by movement of the needle. In other words, the main jet orifice isn't reduced or enlarged by changes in height of the needle.

At least that's my understanding.

Good Fortune!