Make sure that you have a fresh plug. If you sent it to a dealership, then they aren't guaranteed to be good mechs, and it is very possible that they left the old plug in it. You might also adjust the mix screw yourself, dealership wrench-turners are also lazy at times, and may have just returned it to stock and gave it back. Other than that I use 93 pump gas with Motul (on an old top end), and my boy's bike is usully running within 6 kicks.
As for the flooding when it's on it's side, the float doesn't work very well when it in on it's end, so the flooding just happens. The hardest point is teaching a young boy to know what to do and when.