Running Lean?

Btw that's a huge jet spread on your carb. I don't know the stock jetting for your particular carb, but it's possible you're either slighly lean on the primaries, or over rich while on the secondaries, or both.

A general rule of thumb for a carb that has a powervalve in the primaries and no powervalve in the secondaries is 8-12 jet sizes. I'm thinking there's something wrong with a 22 jet spread.