Years ago I installed a Mikuni carb on my Onan powered Quickie.
I thought the carb was too big (28mm) because it ran better at less than
3/4 throttle.After working with it foe a while I installed the carb heat box.
It ran well at full throttle.
After a little more experimentation, I found that because the carb was mounted
with the inlet direction at 90 degrees from the prop air flow, just protecting
it from "side ways" blast solved the problem.
I'm pretty sure that Revmasters don't have a sideways mounted carb, but
thought I'd mention it anyway.

Good luck

Dennis