Can someone please help me out? I recently purchased a Coleman CT200u for my son. When I got it it seemed like it ran ok. After riding it for a bit the engine shut off. Had to use the choke to get it started which it did. I moved the choke to open and it ran ok. It would shut off when taking off. Thinking the carb has some dirt I removed the carb cleaned it but couldn’t remove the needle. So I purchased a new carb from Amazon. Got it installed and it seemed ok but now it’s sputtering and breaking up when top speed. Cleaned the plug that was black. Took off the carb and cleaned all jets etc. the tank is really clean and no debris seen. Put it back together and still the same. When it’s about to shut off I Close the choke and it runs rough. I’m really at my wits end with this little bike. Can anyone give me some insight? Any assistance would be greatly appreciated…