So I got a new kit(48cc 2 stroke) and a new bike and slapped it together over the past few days. On my first few test rides I noticed that it wouldnt idle and then the chain fell off the sprocket and the bike fell. Once I got it back up I had readjusted the gas tank, and tightened everything up in case anything was knocked loose but didnt ride it again because I had to be at work. Today I took it for another ride and the motor would start but it wouldnt accelerate. If I wasnt peddling fast enough the motor would shut off. When i pull the throttle I can hear it kind of revving the motor but theres no acceleration. This is my first build and so I'm not really sure where to start to figure out what's going wrong.