The John Deere Gator is a utility vehicle that features a 10-horsepower Kawasaki engine and a top speed of 15 mpg. As the engine begins to wear, it can start to surge while idling -- worse case scenario, the engine will no longer run in the idle position. Adjusting the low-speed adjustment screw located on the carburetor can get your John Deere Gator back to its peak performance. The procedure will take five minutes to complete.
Park the machine on a hard, level surface, turn the key in the ignition to the "OFF" position and place the gear shift to "NEUTRAL." Pull up on the parking brake until it locks into position.
Open the rear gate and lock into place to expose the engine. Locate the carburetor on the right side of the engine, beside the valve cover. On top of the carburetor are two screws, the low-speed adjustment screw that goes directly into the carburetor, and the idle adjustment screw that sits against the throttle linkage. If there is a limiter cap on top of the former screw, remove the cap with the needle nose pliers.
Turn the low-speed adjustment screw clockwise until it lightly seats and then turn the screw counterclockwise 1 and 3/8 of a turn. Start the engine and advance to half throttle; allow to warm up for five minutes. Release the throttle back to idle.
Turn the idle adjustment screw slowly counterclockwise until it no longer is touching the throttle linkage. Turn the low-speed screw again clockwise until the engine starts to slow down and note the position. Turn the low-speed screw counterclockwise until the engine speeds up and then starts to slow. Note the position of the screw.
Adjust the low-speed screw in between the two noted positions and then turn counterclockwise an additional 1/4 turn. If there were limiter caps on the adjustment screw, press back on the low-speed screw.