Kawasaki Mules are all-terrain vehicles with four-wheel-drive. They are used by farmers and hunters to haul equipment and work gear to remote locations in farms and fields. Sometimes the factory settings put the idle at too high of a speed for the engine to handle, which causes the engine to stall and the gears to grind when they are shifted. Fortunately, the idle speed doesn't have to be adjusted by a mechanic. Anyone can do the job with a simple turn of a screw.
Remove the screws that hold the black metal cover to the carburettor. Take off the metal cover and set it aside in a safe location.
Locate the idle adjust screw, or accelerator stop screw on the side of the carburettor that is above the top of the rear axle of the vehicle. Loosen the idle adjust screw by moving it a 1/4 turn, counter-clockwise.
Start the engine and see if it runs smoother. If not, keep adjusting the screw, 1/4 turn at a time until it does. Stop adjusting when the engine idles at a speed somewhere between 850 and 950 RPM.
There are two brass mixture screws located at the top of the carburettor, one for each cylinder of the engine. Give them a few turns and return them to their original position to keep them from corroding in place. These screws are fragile and can be stripped of their threading easily if they are not kept in working order.