for me an old NT
I have had three carbs since I started this hobby. The first and third on ether flooded my motor or did not work at all. the second one is the one that I am using right now. it is a simple NT carb with a small size chamber. I am also using the manifold that came with that particular carb because its made out of a cast piece of aluminum instead of the bent/welded sheet metal one that came with the motor.
the gas mileage I get out of this carb is over a hundred miles a gallon, where I would get less than half that out of the "upgraded" one that came with the new engine.
the motor I am currently using is a Skyhawk 66 and I am petty happy with it so far, other than the chain broke, the CDI was defective and the carb flooded the engine its worked out grate.
mike