How to Maintain Lawn Mower Blades


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Naturally, your lawn mower blades are eventually going to wear out however, you’ll be able to get the maximum use out of them if you maintain them properly.

Unfortunately, there are many things that can happen to your lawn mower blades that can cause them to get damaged even if you take good care of them and you’re careful as you’re mowing. In the worst-case scenario, the blades could break to the point where they are no longer usable and that is something no homeowner wants to experience.

In this article, I’ll cover some of basics that any lawn mower owner needs to know about properly looking after the blades.

Sharpening the blades

As a general rule, you should have your lawn mower blades sharpened twice a season.

  1. Once in the beginning of the warm weather.
  2. Once in the middle of the season.

Other than that, you’ll need to keep an eye on how the blade performs from week to week to make sure that they are sharp enough to proceed.

Knowing when to sharpen or replace mower blades

There are certain telltale signs that your mower blades either need to be sharpened or replaced altogether.

When mowing the lawn, you should be paying attention to the following:

This sharpening tool on Amazon works well. You could also use a file if your prefer.

Look at how even the cut is

If your lawn is uneven when you get through mowing it, this could be a sign that your mower blades are kaput.

When your blades are nice and sharp, they will hit every piece of grass at the same angle and the grass will be nice and even when you’re done.

If your blades are dull, you’ll notice patches of uncut grass that you’ll have to go back over with your mower to get even. This is a sign that something is wrong with your blades.

The look of the tips of grass blades

If you bend down and inspect your grass and notice that the tips look as if they’ve been torn and not cut, chances are good that the mower blade needs to be replaced.

This is crucial even if you don’t care that the blades have this look because it can also mean that the health of the grass can be affected. Eventually, your grass will be dull-looking and brown instead of lush and green so you’ll want your mower blade to be sharp enough to cut the tips of the grass in an even fashion every time.

Essentially, if your lawn doesn’t look as you think it should when you’re done mowing, if it’s difficult to operate your lawn mower, or the mower feels wobbly or uneven as you work, there is a chance that something wrong with the lawn mower blades.

Damage to the blade itself

Unseen debris and other items can be there in the grass and if your grass is especially tall, you can accidentally run over those items in an instant and cause huge problems with the mower blades.

If you inspect your lawn mower blades, you can usually tell when the blades need to be replaced. If they have large dents or chips that you cannot smooth out or if you are continuously sharpening the blade to no avail, this is not a good sign.

You can also look at the thickness of the blade because over time, the debris that results from continuous grass cutting can erode the blade itself, which renders it useless.

If you’re mowing and you hit something that causes damage, you’ll usually know it immediately because you’ll hear a very loud sound. Sometimes you’ll even know what you ran over with your mower because you’ll recognize the sound, especially if you hit a stone, rock, or some other large item in the yard.

Whether you recognize the sound or not, you’ll need to check the blades immediately to ascertain the damages so you can know what to do next.

If you’re unsure whether a lawn mower blade needs to be replaced...
If you’re unsure you can always consult with one of the experts at your home improvement or hardware store.

How to Maintain Your Lawn Mower Blades?

With all this talk of replacing blades and making sure that they’re sharp, you might be wondering how to properly maintain your mower blades so that they can last longer and require less work in the meantime. Fortunately, lawn mower blades are relatively easy to maintain because in addition to twice-a-season sharpening, the rest is very simple.

Below are a few things you’ll want to do to keep your lawn mower blades in excellent condition so that they are more functional and useful to you:

Rinse them

You can keep lawn mower blades clean by spraying them with a water hose after each use. It gets them super clean and makes it easy to keep them free of debris week after week.

Keep large chunks of debris off of the blades

If you need to, use a steel brush to get big chunks of debris off of the blades. Make sure that you pull out all of the clips and that none of the grass clippings or debris have gone into the engine.

Replace a damaged blade!
If you inspect the blade and notice that it is worn, bent, or in any way damaged, you’ll want to go ahead and replace it with a brand-new blade as soon as possible.

How to replace a mower blade yourself

If you do need to sharpen your blades, you have two options. You can either have the blades professionally sharpened or do them yourself.

If you decide to sharpen them yourself, here is what you’ll need to do:

Removing the blade

Turn off the spark plugs in your mower and remove the blades according to the manufacturer’s directions. If you aren’t sure how to do this correctly, consult the owner’s manual or look it up online. This step needs to be done correctly or you’ll ruin the blades and cause yourself a whole lot of other problems.

Use a file to sharpen the blade

After you’re determined that sharpening the blades is all you need and not a total replacement, use a file (link to Amazon) to sharpen them. This is easiest done with a file that is at least 10 inches long. Filing the blade in the proper direction, you’ll likely need around 50 strokes to do the job right, maybe even less.

Check the balance of the blade

There are balancing machines you can use to make sure that the blades are balanced correctly. This is a very important step of the process so it will behoove you to get one of these machines.

This universal blade balancer on Amazon is really useful.

Reinstall the blades

Again, make sure that it is done correctly. The last thing you should do is hand-tighten the bolts so they are tight and not in any way loose. This keeps the mower running efficiently and keeps everyone around you much safer.

https://www.youtube.com/watch?v=YkqnF-E4LM8

How to Change Your Lawn Mower Blades

While changing your lawn mower blades might sound like a job for a professional mechanic, the truth is that you can likely do it yourself once you learn exactly how to do it.

The first thing you need to do is remove your spark plug wire so that the engine doesn’t accidentally start to run as you work. Place the wire to your side, then turn the mower on its side with the air filter facing up so that oil doesn’t get into that filter and saturate it.

After this, just follow these simple steps:

  • Put on work gloves, then place a 2×4 in between the lawn mower blade and the mower deck. With a combination wrench, go ahead and loosen any fasteners that are attaching the blades to the drive shaft. Make sure that you remove one or both bolts as well as any washers that might be included in the setup.
  • At this point, you might want to take a picture underneath the lawn mower in case you get confused later as to how to put everything back together. Then, go ahead and remove the blade assembly.
  • Check everything under the mower to make sure that nothing is stuck anywhere and that nothing is broken. Just inspect the entire section to make sure that everything looks “right” before you go any further.
  • Put the new blade in according to the instructions and the picture that you took earlier. Make sure that the blade’s cutting edge follows the direction of the rotation. The blade’s wings will usually face up towards the mower deck and if there is any writing on the blade, it likely needs to be facing away from the deck. If the mower has washers to go with the bolts, make sure that their concave side faces the blade.
  • After reinserting the wooden block, this time placing it on the opposite side of the mower deck, tighten the bolts securely with either a torque or combination wrench. You’ll need to read the manufacturer’s directions first to make sure that you end up using the right one.

In Summary

Mowing your lawn should not be difficult and should always produce the results that you desire, so if anything out of the ordinary happens as you’re mowing, the first step is to determine what the problem is so you can do something about it.

The idea is to familiarize yourself with your own lawn mower so that as soon as anything goes wrong, you’ll notice it and you’ll know what to do about it.

If your mower blades aren’t fitted properly, they are damaged, or they are not sharp enough, you’ll usually know instantly because the lawn mower simply won’t work the way it should.

The main symptom of a damaged or ill-fitting mower blade is the lack of efficiency as you’re cutting your grass.

It won’t cut the grass evenly and maybe it won’t cut it at all. Sometimes you’ll feel as if the mower isn’t even on because it isn’t doing anything. Even worse are symptoms such as the blades of grass being “torn” at the top and not evenly cut, and this problem is more than about aesthetics. When this happens, your grass won’t get the attention it deserves and may even lose moisture and nutrients, which means that it will eventually start to turn brown and look unhealthy.

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