If at a steady cruise speed, the motor lurges/stammers slightly (runs un-even, feels like the motor wants to rock back and forth) the primary main jets are too lean. If wide open throttle feels lacking power, secondary main jets are too lean. And, on vacuum secondary carbs, if at wide open throttle it feels like a slight delay then ramps up throttle, the secondaries are opening too soon, install heavier secondary vacuum springs until this condition goes away.

Good luck!