The parts that wear out the most,are the needle,needle jet,the float valve & float valve seat. Most carb kits do not contain the the needle jet,a matched set (needle,needle jet)
can make all the deference in the world compared to a rebuild with out the jet. I won't
buy ones that don't have the needle jet. These two assembles are the ones with moving parts,not to say that the gaskets and O rings can be overlooked! If a part moves it will wear! Head