The HW-10B is based on the HW-10A except it has a metric thread on the adjustment jets to de-sensitive the adjustment of the jet and improving the user-friendliness. It is also fitted with a half shaft butterfly system to improve the performance slightly over the HW-10A.

  • Butterfly Opening
  • Avenger Class Venturi/Body Design
  • Avenger Class Inlet Needle and Seat Design
  • Avenger Class Idle/Acceleration Nozzle Design
  • Easy-Adjust High Low needles


Can also be used to replace an HL carburetor with similar size venturi and throttle bore, such as the HL-334A (but check your local race regulations to be sure the carburetor model is not mandated).

Can also be used with 4-stroke engines if modified for pulse hole.

Carburetor Settings

The HW-10B uses a different adjustment screw than the HW-10A. These Easy Adjust needles make it easier to find the proper setting by allowing a broader range of adjustment.  This carburetor is now CIK homologated for all KF3 races including the CIK Championship Series.  KF Engines vary by manufacturer, manufacture date and tuning.  For optimum performance, you might need to try different settings.  Below is the factory setting.  Adjust first the High then the Low  needle each in 1 minute increments (you should not need to adjust more than 10 minutes in normal conditions, but more in extreme conditions like hot or rainy weather).

L=2 turns 20 minutes (2′ 20″); H=1 Turn 0 minutes (1′ 0″)

Repair Kit and Diaphragm Gasket for carburetor:

Main: RK 1 HW and DG 1 HW

Optional: Rk 2 HW and DG 2 HW

Weight1 kg
Venturi Diameter


Throttle Bore Diameter


Racing Class

Product Line


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