I've had 2 RS. (V and TD) Played with carbs a fair bit. Always took off carb heaters (not needed) and AIS sys (also not needed). Both bikes got good mileage (over 40 MPG), spark plugs always looked good and both ran like a bat out of hell. If you worry about pollution on a over 40 MPG vehicle, I hope you're driving a Volt or Prius.