First thing to check is the 4 corner idle screws. Check them to make sure they are not turned the entire way in. You want them turned out about 1 1/2 turns.

How far open are your throttle blades?

Also did the carb come with a sheet with the air bleeds that in the carb? If not you can see a number stamped in them on top of the carb, what sizes are they?

I would also pull both power valaves and plug them. Jet the carb around 88 squared up. Once you get a good tune with them blocked you can add the front valve again for cruise and jet down.

Lastly check to make sure there is no vacuum leak around the intake or carb.