Don't mess with the mixture screw yet. Was the choke on or off? Are you certain that the throttle cable was properly seated into the top of the carb?
Good job on solving the fuel hose issue. I hadn't thought of that.
You might want to change the oil in the forks; that might make all of the difference. Spud's fork tutorial has all the info you'll need:
http://www.chinariders.net/showthread.php?t=10266 You'll need a quart of Valvoline Maxlife ATF.
An o-ring chain will last longer and be less prone to stretch. It will cost more.
Why is the R6 shock a fail?