There are many maintenance items on your Exmark lawn mower that need to monitored, cleaned or replaced. Your mower blades are one of these maintenance items. They must be kept in good condition to continue to achieve a nice-looking lawn.
I share the steps to change and sharpen your Exmark mower blades along with other important information that will help you maintain and extend the life of your blades.
How Often Should You Change Your Exmark Mower Blades?
Exmark mower blades should be changed at least once a year and more often if you damage or bend a blade. Start each mowing season with a fresh set of blades and sharpen them during the mowing season as needed.
How Often Should You Sharpen Your Exmark Mower Blades?
Exmark mower blades should be sharpened after every 25 hours of use. This amounts to approximately twice a year for the average homeowner. When you are using your Exmark in dusty conditions or in areas with gravel in the lawn, you will wear your blades sooner and require more frequent sharpening than mowing lawns that don’t have these same conditions.
Do New Exmark Mower Blades Need to be Sharpened?
New Exmark mower blades do not need to be sharpened. They have been sharpened during the manufacturing process and coated with a paint. The paint will wear off the blade edge when you initially use your new blade. New Exmark blades are ready to install onto your Exmark.
Inspect Your Exmark Mower Blades for Wear & Damage
Lawn mower blades on your Exmark lawn mower can become worn or damage. This can cause your Exmark to give you an uneven cut in your lawn. Read more about the items that can cause an uneven cut with your Exmark.
Inspect your Exmark blades for wearing and damage and replace when required. Here are some items to check for when inspecting your mower blades:
Wearing on the Exmark Blade Sail
Normal usage of your Exmark can cause your blade sail to wear from the constant movement of dirt under your mower deck. It is time to replace your mower blade when the top of the sail appears thinner than the center of the blade.
Chips & Dings in the Exmark Blade Edge
Your blades come into contact with debris that can cause small chips and dings in your Exmark blade. Most of the time, these chips can be removed during the blade sharpening process. If you develop deep gouges in your blades, you need to replace the blades.
Exmark Blade is Bent
When a mower blade impacts a hard object, it can bend. A bend in your mower blade can cause your uneven cut. There are a couple different ways you can check for a bent mower blade:
- Check for a bent Exmark blade by removing from the deck
Remove your Exmark blade from you mower deck and place it on top of a new blade. If the blades don’t fit together and there is a gap in any area, you need to replace your mower blade.
(Before you remove your mower blade, check for a damaged spindle or spindle housing using the steps listed below in this section).
- Check for a bent Exmark blade while installed on the deck
If you prefer to not remove your Exmark blade to check for a bent blade or you don’t have a new blade on hand to match a potential bent blade up to, then proceed with this procedure to check for a bent blade.
With your mower parked on a level hard surface, measure one side of your blade from the ground to the blade tip and record the measurement. Next, rotate your blade 180 degrees and measure from the same spot on the ground to the tip of the blade. You must remove and replace your blade if the difference in the two measurements is greater than 1/8” difference.
Remember, when the impact to your blade is significant, you can damage your Exmark blade spindle and housing. It’s best to check for damage before you remove your mower blade. With a good pair of work gloves, grab a hold of each side of your blade and rock the blade up and down.
If you feel play or movement, you need to remove your spindle housing assembly and look for damage. You will also need to remove the housing when you hear a knocking sound that could indicate you have a bad bearing in the housing.
When you find a bad bearing in an Exmark spindle housing, the cutter housing assembly must be replaced. Exmark only offers the spindle housing as an assembly as it contains a sealed bearing.
Exmark Blade is Cracked
A cracked Exmark mower blade poses a safety risk. Using a cracked blade can be extremely dangerous because it can break off while mowing. A piece of blade that breaks off while moving at high speeds can injure a person or damage a structure.
Items that Can Damage Your Exmark Mower Blade
Help prevent damage to your mower blades by removing items from the mowing area that can damage your blades. Take time to walk through your yard and look for objects your blades may hit prior to mowing. Here is a list of items that can damage, wear or corrode your mower blade:
- Sticks, Rocks and Toys
Items left in your yard like sticks, rock and toys can cause your blade to bend or become gouged upon impact. Not only can you damage your blade, you can also damage your spindle and spindle housing causing vibration and an uneven cut.
- Sand & Nature’s Debris
If you don’t have a nice thick lush lawn, there isn’t much you can do to prevent an increased level of sand from being sucked into your mower deck and wearing your blades. You will need to plan on sharpening your blades more often while you wait for your grass coverage to fill in.
- Lawn Chemicals
Some homeowners choose to use chemicals on their lawn to help with lawn health and growth. Some of the chemicals used can corrode your deck components and cause your blades to fuse to your mower deck. Remove your mower blades periodically to ensure they don’t form a tight seal that prevents you from removing them next time.
How to Remove & Change Your Exmark Mower Blades
Here are the steps to remove your Exmark mower blades:
Gather Tools to Remove Exmark Blades
- Work Gloves
- Safety Glasses
- Torque Wrench
- Cordless Impact Gun (Optional for Blade Removal)
Remove Exmark Spark Plug Boot
To prevent your mower from starting and your mower deck from engaging, it is important to remove your ignition key and remove the spark plug boots. Stay safe by completing these two tasks along with wearing gloves and safety glasses.
Remove & Reinstall Exmark Mower Blades
Use a socket and ratchet to remove the bolt securing your Exmark blade to the spindle. If it doesn’t come off easily you may want to use a cordless impact gun. You can also attempt to remove a stubborn bolt using a block of wood. Place the block wood over the bolt and hit the block with a hammer to shock and loosen the bolt so you are able to turn the bolt and remove it.
Remove your bolt, washer and blade. Many Exmark mowers will also have a splined bushing that is placed in the center hole that will be removed when you remove the bolt. Reinstall your new or sharpened blades in the opposite order you removed them.
Secure the bolt using a torque wrench. Torque the bolt to 50-60 ft lb. Do not use an impact gun as you can overtighten the bolt and damage the spindle.
How to Safely Sharpen Exmark Lawn Mower Blades DIY
You can save some time and money by sharpening your own Exmark mower blades. There are several different tools that can be used to sharpen your blades including a metal file, drill powered blade sharpener or disc grinder. Follow these steps to sharpen your blades:
Gather the tools you will need
- 10″ flat metal file, drill powered blade sharpener, or disc grinder
- A vice to hold the blade in place
- Blade balancer or nail on the wall
- Wire Brush
- Safety glasses
- Work gloves
Put on Safety Glasses and Gloves
Clean Exmark Blades
Use a rag to clean the dirt off your mower blades. A wire brush can be used for stubborn areas of buildup.
Secure Your Exmark Blade
Securely place your blade in a vice to keep it from shifting during sharpening. After sharpening one side, you will flip the blade and secure in the vice while you sharpen the other side.
File or Grind Blade to Sharpen Edge
Sharpen with a metal file
- Using a file, push the file at an angle in one direction along the blade.
- Do not use a sawing motion when filing.
- Once all the rough spots and uneven edges are removed, flip the blade over, secure in the vice, and sharpen the other side.
Sharpen with a drill powered blade sharpener.
- Power the drill with the blade sharpener attached.
- Place the flat guide of the sharpener along the flat portion of the blade with the cutting edge slot into the bevel.
- Move the sharpener up and down the length of the blade edge.
- Once one side is sharpened without any rough spots or nicks, flip the blade over, secure in the vice, and sharpen using the same procedure.
- Hold angle grinder perpendicular to the edge of the blade. Run the grinder along the length of the blade to level out any rough spots or nicks. Keep the grinder moving so it removes a little metal at a time and produces an even result.
- Once one side is sharpened without any rough spots or nicks, flop the blade over, secure in the vice, and sharpen using the same procedure.
Balance Your Exmark Mower Blades
After you sharpen your mower blades, it’s necessary to balance them so you don’t damage your lawn mower. To have balanced blades means each side of your mower blade is equally weighted. When they don’t have the same weight on both sides of the blade, the blade can cause your Exmark to shake and cause potential spindle housing and engine damage.
Use a blade blade balancer to check for equal weight on each side of your blade. This inexpensive item can save you from a large repair expense as a result of not having your blades properly balanced. To balance your Exmark blades, shave metal off the heavy side of the blade until the weight of the blade is equal on both sides.
Another option to check the balance of your blade is using a nail on the wall where the nail head sits about an inch away from the wall. Place the center hole of the blade over the nail and watch to see if the blade hangs lower on the right or left hand side of the blade. You will want to remove more metal off the side that hangs lower until the blade sits level on the nail.
When You Should Seek a Professional Sharpening Service for Your Exmark
While I can sharpen my own Exmark blades, I choose to have them sharpened professionally by my local Exmark dealer. It cost about $7-$10 a blade to have them sharpened. The dealership always gives me a good sharp edge on my blades and they are balanced and ready to install. They do a better job than I can.
At my dealership, I have to drop off my blades off to be sharpened and pick them up a couple of days later. The timeline works for me because I always have a second set of sharpened blades on hand so the wait isn’t a problem. You may choose to have a professional sharpen your blades because:
- It is a safer option to sharpening the blade yourself
- Sharpening a blade is often less expensive than purchasing a blade
- A professional can grind down mower blades to get rid of large nicks and gouges in the steel
- The blade is properly balanced reducing vibration and damage to your mower deck.