A quick release hub for the outer tires and wheels of dual wheel assemblies on a vehicle such as a mortar buggy to enable the vehicle to move through a narrow doorway or other passageway having a width less than the total distance between the outermost surfaces of the outer tires. The quick release hub includes a two component hub secured together by a single fastening device which enables quick and easy removal and replacement of the outer tires and wheels. A combination engine electrical control switch for the mortar buggy engine automatically controls a fuel supply valve to open and close the fuel valve in response to the engine control switch. An operator's platform and brake actuator are mounted at the rear of the mortar buggy with the brake actuator extending transversely at the forward portion of the platform to enable an operator to use either foot to operate the brake actuator.