How do you change and sharpen riding lawn mower blades?

Answer 1

On a riding mower you will need to safely lift and support the rider somehow so that it can't slip or fall. I have a rope lift I use in the garage but a sturdy tree limb would also work fine. You might be able to elevate one side so that it tilts right or left but do not trust a hydraulic jack to hold it up. Use a tool or a block of wood to prevent the blade from turning. There is a large nut or bolt you must loosen on each blade. Turn it the opposite direction the hands on a clock turn. There should also be a lock washer that prevents the nut from loosening. Save and reuse it. Pay carefull attention to any flat washers that are also fastened with the blade. My older mower has two washers above the blade and one below. Those affect the height of the cut and in some cases must be in that position in order to hold the blade in place.

If you don't have a grinder you can sharpen the blade with a file. It might take awhile but it will work. You can use any bolt or plastic pen as a balance tester. Place the bolt through the hole on the blade and hold it straight out in front of you as if you were pointing the bolt at something in front of you. See if the blade remains fairly level. If one side dips down, it is heavy. Remove some more metal from the low side and retest the balance until it sits fairly level.

While you have the blade off, it would be a good time to clean out the mower deck. Look for grass deposits, wire, string ....anything that will catch grass and slow down the grass from being spun out of the mower.

Replace the blade with the original washers and tighten the nut or bolt using something to prevent the blade from turning. Turn the wrench the same way as the hands on a clock to tighten.

Remember, when it comes to nuts and bolts,
right is tight,
left is loose...

Answer 2

Remove the blade... If you choose to sharpen it using a bench grinder, hold the blade at the approximate angle of the original sharpening and grind it back and forth till the sparks break over the backside of the blade. If you hold it at the same angle throughout the sharpening process, as soon as the sparks break over the back of the blade, the sharpening is complete. This works equally as well if you clamp it in a vise and use a hand grinder, using the same technique. It is always a good idea to balance the blade, and good methods are already available from a number of other responders to your question. A sharp blade always does a superior job, and is noticible when a sharp blade mows verses a dull one. Hope this helps !!!

Answer 3

Take it off (uses a bolt) and sharpen it with a file, grinder.... whatever to sharpen it, when you put it back on be sure to get that bolt nice and TIGHT!!!.

BUT one thing everyone forgot...... balance the blade!!!! take a nail and put it in a post, hang the blade by the bolt hole and sharpen either said it leans towards till its nice and level. This is really important on a pushmower... not so much on a riding mower.... BUT it will still play heck on the spindle bearings.

Answer 4

On the bottom side of your mower, there is a nut that holds on the blade(s). You need to remove this. Most of them are right hand thread, so it is right to loosen, left to tighten. There will probably also be a washer. The best to sharpen them is take them to a shop that can do it. But if you have a grinder, you can do it yourself.

Answer 5

Remove the blades, then either put the blade in a vice, and use a file to sharpen it, or use a bench grinder to sharpen it.

Answer 6

I think there's a nut you have to take off, then put the blade in a vise. Use a really large file, and keep filing the same way, turn it over and repeat.

Answer 7

remove them from under the deck, should be about a 7/8 bolt or so, depending on how big the blades are. put them in a vice and take your trusty file to them. doesnt have to be perfect, just sharper than it was. slap em back in how they came out and your good to go

Answer 8

take it to your lawn mower shop it's cheap and so much easier