The stock intake manifold will gwt cracks over time along with carb failing due to inside chambers getting clogged and frozen due to gas additives that can not be cleaned out inless you pay for sonic cleaning which is price of this kit.
There are better carbs and better intakes costing twice as much so you do have that choice.
This carb can be jetted to perform better.
Kit comes with
GY6 150 24mm Carb
GY6 150 22mm Intake manifold
Main Jet 105
Pilot Jet 35
Perfect replacement or upgrade for 80cc 139QMB upgrade.