The deck on a riding lawn mower needs to be level to ensure a clean, even cut to keep your lawn looking its best. Decks that are not level will leave longer grass blades on one side and shorter grass or scalped areas on the other. It takes relatively little time to adjust the deck on a Murray lawn mower. First check the tires for the proper air pressure to obtain the correct height.
Park your lawn mower on a flat, level surface, such as a garage. Apply the parking brake and turn the ignition key off. Allow the mower to cool completely.
Open the lawn mower hood and pull the rubber spark plug boot off the spark plug to prevent accidental starts. Leave the hood open for adjustments.
Put on safety glasses. Check the air pressure in each tire with a tire gauge. Add air if necessary from an air compressor or air tank so each tire is inflated to 14 psi.
Remove the gauge wheels if your deck has them. The hard plastic gauge wheels mount onto the deck. Place an adjustable wrench on the rear nut and hold it in place while turning the front bolt counterclockwise. Pull the bolt out and take the wheel off and lay it aside.
Open the right-side lift lever cover if your model has one. Push the lift lever down to the bottom and guide it to the "Level Adjustment" position on the right-hand side.
Loosen both wings nuts on each side of the lawn mower, just above the deck. These left and right adjuster knobs are just below the metal lift link on the front of the deck that attaches to the lift lever for cutting height adjustment. There is also a rear lift link attached to the deck.
Press the lawn mower deck down on all sides so that the bottom rests on the flat surface on all sides. Press down on the front and rear lift links to release any slack in the lifting system.
Tighten both adjuster knobs clockwise until hand-tight, then completely with an adjustable wrench.
Move the lift lever down, to the left and upward into any cutting height you choose. Close the lift lever cover, if your model has one.
Reinstall the gauge wheels and connect the spark plug wire.