When I let off the throttle from full speed the engine is slow to idle down. I just kitted the carb and cleaned it,checked all the orfices and put a new fuel filter in the tank. If the reed valve is bad could that cause it to take to long to get back down to idle? I made sure the carb is tight and new gaskets. Could crank shaft seals cause this? It seems like a vacume leak/ lean prob.