The Choke Shaft Assembly fits most Clone or Predator Carburetors and Engines. 

The Choke Shutter System works by closing off incoming air and allowing the engine to pull more vacuum inside the carburetor drawing fuel out the fuel circuits to start the engine. The Choke system is required by most box stock classes but is often optional for SA Classes. If the choke system is removed you can still choke the carburetor with your hand by cupping the filter adaptor or a crush-style air filter. Once the engine has cold started the engine should start without the choke. 

The Clone Throttle Shaft Kit fits most Clone Carburetors including the Tillotson PK-1, Hyuai, Ruixing, and SP Carburetors on the Honda GX200, Ducar 196, Ducar/Tillotson 212E, Tillotson 196R/RS, Tillotson 212R, Ducar/Tillotson 212E, Predator 212 and BSP 196 and 212 Engines.

AKRA 2020 Rules for Choke Assembly
Choke must be as supplied from the factory, but maybe fixed to stay in open position. (Choke area must remain as cast.)

NKA 2020 Rules for Choke Assembly

40.4.11.2: Choke Assembly

40.4.11.2.1: Choke assembly must be in place and functional. 

40.4.11.2.2: Choke lever must be stock. Drilling holes to mount choke lever is prohibited.