Brand new tbr7 won’t stay running

[James2727]

I bought 2 new tbr7 and put them together I also bought new clone carbs for them. I put a 110 main jet in both of them and left everything else the same. I then set the air/fuel screw 2 and half turns out. One bike is running good and the other I can’t get to stay on the exhaust gets hot really fast when I can get it to stay on for a few seconds and I can smell strong odor of gas. What could be wrong. Any help is appreciated