I'm having some problems going up hill on my bike . Somehow the bike seems to cut out like no fuel or like a vacuum hesistation. I get no power and then hesistation and dies. On flat lands the bike runs perfectly fine. It starts to do this once i start going up hills. Anyone know what the problem could be? I just just got the bike tuned up too. Before i had this problem but i found out it was a vacuum leak. But now i'm not sure.... Please help me out.