grease monkey

i have a 02 banshee and it wont start unless i pour gas into both carbs. it will idle with the park brake set but it doesnt sound like it is hitting very good on the left side. if i take the park brake off it will rev up but wont idle at all i just rebuilt the top end and rebuilt both carbs. the banshee is a new world for me if anybody can help me out that woulb be great.