How to Change the Blades on a Scag Mower

Changing the blades you use on your Scag mower is an important part of maintenance for keeping a clean, leveled-out cut as well as keeping your mower running efficiently. In case you are putting in a new set of dull blades or sharpening the blades for another season of mowing, that is when it is important to follow the right steps as needed.

Safety Precautions

Starting at a safe distance, first check to make sure the mower is turned off and the spark plug wire is disconnected. This will prevent any accidental starts while taking the blade off. Also, simply put on a pair of gloves or safety glasses at this time, avoiding any potential cuts or injuries to yourself while working on the mower or handling any debris.

Prepare your Scag Mower

Make sure that the mower is on a flat and level surface as well as in park with the parking brake engaged. If you’re working on a riding mower, lower the deck to its low position. Make sure to clean off any dirt or grass built up on the deck area. This allows you to have a clear view of the blades and the area to remove or replace the blades.

Lift and Secure the Mower

For zero-turn or walk-behind models of Scag Mowers, it is suggested to use a mower jack or lift to raise the deck enough to comfortably access the blades. Lastly, make sure that the mower is stable and that it is not going to work or shift while working underneath.

Step-by-Step Guide for Changing Blades

Step	Action	Explanation
Step 1	Locate the Blade Bolt	Locate the bolt in the center of the blade, which fastens the blade to the spindle assembly. This bolt is usually located in the center of each blade.
Step 2	Lock the Blade	Use either a wood block or the blade lock tool to lock the blade in place so it does not turn while loosening the bolt.
Step 3	Unscrew the Bolt	Loosening the bolt means turning the bolt counter-clockwise with a ratchet or impact wrench to free the bolt from the blade. It may be useful to note the order of any spacers or washers to allow proper reassembly.
Step 4	Pull Off the Blade	Carefully pull the blade off the spindle shaft. Again, blades that have worn dull will still cut easily.
Step 5	Check and Clean	Examine the spindle area and the blade surface in detail for wear, rust, dovetails, cracks, or irregularities prior to resharpening or reinstalling the blade.

Reinstalling Your New Blades

When reinstalling:

Double-check that the cutting edge is facing the correct direction of rotation (facing the front of the mower).
See the Scag manual for the torque specification for the bolt that holds the blade on, usually in the range of 70–90 ft-lbs to avoid the blade loosening during work.

Maintenance and OEM Parts

Regular maintenance keeps your Scag mower at peak performance. When it's time to replace your blade, make sure you use an OEM Scag mower blade made specifically for your model, as it will help maintain the balance and cutting height of the mower throughout its life. Our online store has an entire range of Scag replacement parts and Tune-up Kits, including: