The fella that ported your motor should be able to get you in the ball park with jetting unless you are using a carb he's not familiar with, ask him what slide, pilots, needle, needle jet and mains he uses.
I'm offering suggestions based on you saying the bike has no go off the line but then won't rev past 4k?
I like to start tuning with the idle circuit and work up. Who cares about the main, it doesn't effect idle but pilot and needle will bleed into the main. Get the bike sorted to 1/2 throttle then work on the mains.