I have a cen fun factor. When I accelerate open the carburetor as quickly as possible it takes ages for the car to take off. It just sits there and revs up. When the carb is closed again it then begins to accelerate. What is wrong.

Does the motor sort of bog out when you give it full throttle? If that happens your running to lean.

What do you mean when you say it accelerates when the carb is closed?

look up alot of tuning guides and read them all, here is a good one http://www.*********.org/cars_eng-tuning.htm read it all, its completely worth it

it may be lean and the throttle servo is very slow, when you open throttle it is lean, when it closes then the fuel from the bottom end hits and causes this.