Theres no reason why you shouldnt be able to get those numbers. I am getting 7400 on a pretty much stock engine with free flowing muffler and 12.7 mm venturi. i am using the xyz ignition set at 28 deg. i got the best ring seal i can get with a good cylinder and two ring piston. and i moved the cylinder down .020 to up compression and thats about it really.
What is you cylinder? does it have the two runner per side transfer ports or the one runner per side?
by the way it is a stock carb the prop is a mas 18/8 michael
ditch the stock carb for sure, there just to puny. that will make i big diff right there. what about muffler??? what are you using there?