air intake

Hey Everyone, I am constantly tinkering with my first build - I can't seem to get it to run quite right. I am running a YD100 engine with an NT carb mounted to a Mongoose dirt bike. I've recently done some modifications but now my bike runs TERRIBLY. Can't even crack 5 mph on flat ground and...

I've had this gt-5 for a few months now. It starts imediatelly and idles great. For some reason once i reach an RPM range the motor backs off like its loosing fuel\air. I think there is a leak in my air intake somewhere. I have a carb ring from Sick Bike Parts and the intake itself is air tight...