Abstract: A readily mountable and removable carburetor-adjusting control harness accessory for use with a jet-propelled personal watercraft having a deck with a top engine compartment opening and a hood in sealed engagement with the deck at the periphery of the compartment opening to prevent entry of water into the Compartment, the harness having at least one coaxial structure comprising an outer casing and an inner flexible rotatable but non-twistable shaft, one end of the casing of each coaxial structure being in sealed relationship between the hood and the deck with that one end extending to the outside of the compartment when the compartment is closed by the hood, the inner shaft of each said structure extending throughout the length of the respective casing and beyond the ends of the casing, the outer manually accessible end of each shaft having a manually rotatable knob thereon for remote adjustment of a carburetor adjusting member on the other end of the shaft, a bracket structure for anchoring the carburetor en