The blade on my Honda petrol push mower is bent. Should I hammer it flat and continue

J

Julian

New member
mowing ? Yesterday, I ran over a metal spike while mowing the lawn. The mower will still start but it vibrates like crazy, makes tons of noise and occasionally blows black smoke. After reading a couple of web forums on the subject, I came to the conclusion that the blade was bent. However I do not remember what the blade was like in the first place so I can not be sure... If it is bent, I do not think it is bent that much. Is it possible to hammer the blade as flat as I can and keep mowing or do I have to buy a new blade/seek professional help?
Thank you
 
B-a-l-a-n-c-e (in the voice of Sean Connery in Highlander).

Blades are normally made from a flat piece of steel, with the cutting edges bent down slightly, and the trailing edges bent up to create the draft that pulls grass up into the blade.

Both ends of the blade need to be about the same shape. The blade also needs to balance finely about it's pivot point.

I'm wondering whether the bearings took a hit. Still, try sorting out the blade first - it'll hopefully be just that.
 
The standard advice is to replace the blade. That's due to the wear on the engine drive bearings if you fail to return the blade to original shape when you bend it back, as well as the chance that even a slightly bent blade might work itself loose somehow. The latter is unlikely, due to centripital force of the blade and the direction of the threads vs the rotation of the engine. But still, the official advice is replace the blade. But if you can't get one right away and want to finish mowing, What you want is symetry, each side being the mirror image of what is on the other side of the center hole. The best way I have found to re-bend a blade is to place it in a vise just below the start of the errant bend, and wrap the free section in a towel and use my arms to bend the blade back into shape. It might work fine, or it might not, generally having to do with how mich spring is in the metal at that part of the blade. If it seems to work well, and the blade looks very symetrical, I've been known to reinstall and use the blade for years. But I'm a little more risk tolerant than most, and I check the tightness of that blade more often than one that hasn't been bent. So I do recommend replacement, even if it seems okay in the short run. You can always keep a blade you have successfully re-bent as a short term spare in the event your new blade bends as well.

Good luck
 
Trying to get your blade rebalanced by hammering it is a useless task. You would do well to just purchase a new one.

Be sure and pull the spark plug wire off before you start any work on the mower so you don't accidentally start the mower.

You could also have a bent shaft but usually that is not the case.
 
The standard advice is to replace the blade. That's due to the wear on the engine drive bearings if you fail to return the blade to original shape when you bend it back, as well as the chance that even a slightly bent blade might work itself loose somehow. The latter is unlikely, due to centripital force of the blade and the direction of the threads vs the rotation of the engine. But still, the official advice is replace the blade. But if you can't get one right away and want to finish mowing, What you want is symetry, each side being the mirror image of what is on the other side of the center hole. The best way I have found to re-bend a blade is to place it in a vise just below the start of the errant bend, and wrap the free section in a towel and use my arms to bend the blade back into shape. It might work fine, or it might not, generally having to do with how mich spring is in the metal at that part of the blade. If it seems to work well, and the blade looks very symetrical, I've been known to reinstall and use the blade for years. But I'm a little more risk tolerant than most, and I check the tightness of that blade more often than one that hasn't been bent. So I do recommend replacement, even if it seems okay in the short run. You can always keep a blade you have successfully re-bent as a short term spare in the event your new blade bends as well.

Good luck
 
Trying to get your blade rebalanced by hammering it is a useless task. You would do well to just purchase a new one.

Be sure and pull the spark plug wire off before you start any work on the mower so you don't accidentally start the mower.

You could also have a bent shaft but usually that is not the case.
 
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