An adjustment limiting device for a carburetor including a fuel adjustment valve rotatable to adjust a supply of fuel in or delivered from the carburetor includes an adjustment limiting cap and a connector. The adjustment limiting cap is adapted to be disposed over a portion of the fuel adjustment valve and includes a rotary connection feature adapted to limit relative rotational movement between the adjustment limiting cap and the fuel adjustment valve, and a rotation limiter to limit rotational movement of the adjustment limiting cap. The connector may be carried by the adjustment limiting cap to maintain the adjustment limiting cap on the fuel adjustment valve. The connector may be concealed by the carburetor body, permit the adjustment limiting cap to be fitted onto the fuel adjustment valve, and prevent the adjustment limiting cap from being removed from the fuel adjustment limiting valve.