i agree with dizzie just shed as much weight as possible, then start stiffenning the thing up then get a decent air filter, then exhaust, then cam, then head work then ......... it depends how much of a budget your on as to how far you want to go.
if its a digifant, open up the air box and pull out the trumpet thing for starters, if it hasn't already been binned and then get a k&n and drill some big ass holes in the wing side of the air box. thats all cheap/free things to start with.