OEM bs aftermarket carburetor

[Superthrash1]

So I’m having an issue with the carb/jetting. Raptor 350 with a big bore 366. I can get it to idle just fine but it won’t rev out with any main jet from 145-180. I have a Zoom Zoom carb in it now that replaced the aftermarket carb that was on it when I got it. Other keys are factory size. It’s at a shop right now and the guy says that non OEM are very hard to tune?? Any suggestions?

 

[Centex]

My zoom zoom has been pretty easy. Adjusted idle and air screw and that was it. But it’s a stock engine.