Emulsion Tube or Dellorto "Atomizer" for Rotax Max Kart Engines. This is the standard atomizer and emulsion tube for Rotax Dellorto VHSB carburetors, and is a key component to keep clean and maintain in your carburetor!
The emulsion tube in any carburetor is where the real 'magic' of carburetion happens - in the atomization of the fuel-air mixture! This tube is a specific diameter and features perforations to aid in making the fuel / air mixture into small droplets for proper inhalation into the engine for combustion.
Note on the Rotax carburetor a specialized 'stepped' 7mm socket must be used to remove the emulsion tube. While one can be fashioned from a 7mm socket, most tech officials at the track will have their own specialty tool for this exact task.
As the main jet precedes the emulsion tube, it is possible over time for wear of fluid passage to affect the size of the emulsion tube - we have seen this inspected in technical inspections before. Make sure to check the spec on this emulsion tube from time to time to ensure compliance!