I have encountered this problem before. Definitely I assure you that it is an intake leak that causes the high acceleration and engine could not idle. First make sure that all parts and jets from your carbs are clean. Do not always assume that it is clean once you open from the box. Then get your self a fresh Carburator Union washer from DAX ENGINE_KIT_PARTS_PAGE_2
and a new gasket. If it still did not work replace your intake and the same time replace the intake studs and bolts. Good Luck.