To repair the carburetor on a Murray riding mower, alter the position of the carburetor's needle valve, and remove any blockages in the air vent of the gas tank to resolve engine air intake issues. Also, clean the nut of the carburetor's bowl to remove accumulated fuel residue.
Begin repairing the carburetor on a Murray riding mower by switching off power to the vehicle and opening the front engine's hood. Then, locate the carburetor. This bowl-shaped component is normally towards the center of the right side of the engine.
Now, grip the needle valve located at the bottom of the carburetor, turn it fully towards the right, and then two turns towards the left. Switch on the riding mower, and listen for sputtering of the engine. If the engine sputters, adjust the needle valve to the left or right till the sputtering stops.
If the mower still does not function correctly, remove the fuel tank's cap. Check for any blockages in the air vent hole in the cap, and remove the same using a pipe cleaner. Replace the cap, and run the mower.
If this does not fix the issue, keep a pan beneath the carburetor, loosen the nut of the carburetor bowl located at its bottom with a socket wrench, and allow the fuel to drain out completely. Then, remove the nut, wipe it with a cloth, and dip it in a cleaning solution meant for carburetor cleaning. Scrub away fuel residue using a wire brush. Finally, tighten the nut to replace the carburetor's bowl.