Tillotson throttle shafts do more than hold and control the throttle shutter/butterfly.

The throttle shaft is specific to particular designed carburetor bodies to pull from different sides of the carburetor and in different directions. This helps to identify the application of the carburetor in many cases.

13-2129 Tillotson Throttle shaft & lever w/cable swivel assy (pulls up toward fuel inlet). Fits HL-304WX, WXA, WXG, HL-334WX, WXA&WXG, HL-388A

These carburetors are primarily OHV carburetors.

Will also, fit all carburetors using the 13-1894 shaft if you want to change the direction you want to pull your throttle cable.