Can someone please help me out. Jets are hard to find in any sizes. If possible I can get a few MC28 jets from 170- 198 mains, but don't know whether it will work on my MC21.

The reason I'm asking is that I would like to fit my air box again as I am running open carbs at the moment. My jets are as follow:
Main jets: 185 ; 188
Slow jets: 40 ; 40
Air screws: 1.5 turns out
Power jets: blocked
Floats set at 12mm using Tyga's method.

The bike seems to over fuel a bit. I want to change my jetting for the air box fitment but would like to stay pre-mix. Anyone who can help please? And any suggestions on jetting?

Performance wise:
Bosson exhausts
HRC Reeds (not carbon flaps though)
Light weight flywheel (890g)
PGM CDI (or PGM 1)
Engine 100% except the barrels. (Getting new ones)