dies after going up a hill

[iMoon1221]

So.. my wasn't running for a while so I reversed everything I did. I somehow got it running.
No it starts up fine and rides normal at first. But whenever I go up this big hill in my neighborhood it dies after I get over the top. It revs really low then stops then goes really high. And it keeps doing it. Today that happened so I coasted down the hill and parked it in my driveway. I had my dad come out to hear it. When I first revved it it was weird but quickly went back to normal.
What's going on?