Does my go kart need a new clutch?

I give it full throttle & it revs up & moves slowly then it picks up speed. its a briggs & stratton 5hp engine on an all terrain go kart (pretty big) its like it lacks torque or maybe its geared up for top end speed & not take off speed.???? can i adjust the clutch so that it engages better (like at lower rpms so it wont rev out) or mabe buy havier clutch shoes so it engage's sooner?