A great upgrade, works best will billet intake, or simply with larger manifolds. These are Keihin race style carbs with power-jet feature.
This feature is great for added top end fuel, allows you to tune a little leaner down low for a crisp throttle response and added richer mixture on wide open throttle for a healthier running engine. Also a great option for the RD350 rd400 rz350 and many other 2 stroke engines.