[ChrisJJ]

Hi,
Our mower (a basic craftsman push mower)was in the shop because the engine would only run a minute before spluttering to a stop. While it was there I asked them to sharpen the blade.

I picked it up yesterday and today when I started it up, I noticed the engine was working fine but the cutting didn't sound right - it sounded the same no matter what I'm going over or how thick the grass. If it was a vacuum I'd say it lost suction. I noticed that it wasn't cutting well - it only cut things that were standing up but wasn't cutting grass blades that were laying down The cutting doesn't look even and I'm seeing high stems here & there. It looks like the flower or grass seeds were yanked off leaving the stems.

I'm thinking the trouble is with the blade. Is it possible that it's upside down? I looked at the manual but found the drawing on blade attachment less than enlightening. When I look at the blade, I don't see much sign of sharpening. In fact I'm having trouble figuring out which is the leading edge. Shouldn't I see bare metal on the edge?

I'm going to call up the engine repair guys but I would appreciate feedback on this so I can sound like I kind of know what's going on.

 

[DexterII]

When the blade is cutting, the more-or-less flat side should be down, and the beveled edge, as well as the sail, opposite the cutting edge, should be up. Disconnect the spark plug before inspecting it, and, if possible, keep it level, and set it up on saw horses or something to inspect it. If you have to tip it on its' side to inspect it, be careful that the oil does not run out, and do not leave it in any position other than normal for an extended period of time. Also check your height adjustments, as maybe someone changed them.

 

[Bud Cline]

I wonder if maybe they swapped blades by mistake. The blades must be removed to sharpen them. The blades are also what produces the dynamics of the suction effect. There are different shaped blades used for different purposes. Maybe you now have someone else's blades.

 

[95025]

Hi,
Our mower (a basic craftsman push mower)was in the shop because the engine would only run a minute before spluttering to a stop. While it was there I asked them to sharpen the blade.

I picked it up yesterday and today when I started it up, I noticed the engine was working fine but the cutting didn't sound right - it sounded the same no matter what I'm going over or how thick the grass. If it was a vacuum I'd say it lost suction. I noticed that it wasn't cutting well - it only cut things that were standing up but wasn't cutting grass blades that were laying down The cutting doesn't look even and I'm seeing high stems here & there. It looks like the flower or grass seeds were yanked off leaving the stems.

I'm thinking the trouble is with the blade. Is it possible that it's upside down? I looked at the manual but found the drawing on blade attachment less than enlightening. When I look at the blade, I don't see much sign of sharpening. In fact I'm having trouble figuring out which is the leading edge. Shouldn't I see bare metal on the edge?

I'm going to call up the engine repair guys but I would appreciate feedback on this so I can sound like I kind of know what's going on.

If you're wondering which way the blade should spin, prop the mower up, disconnect the spark plug, and slowly pull on the starter cord. The blade will move in the direction the engine runs.

It should be very obvious if the blade was sharpened. You should be able to, if nothing else, run your finger along the cutting edge and feel that it's sharp.


The bottom line is that something is wrong with the blade. It's remotely possible that they mounted it upside down. It's also possible that they put the wrong blade on - though different mowers have very different blades, so that's not likely. It could also be that they simply failed to sharpen the blade.

 

[user1007]

I wonder if maybe they swapped blades by mistake. The blades must be removed to sharpen them. The blades are also what produces the dynamics of the suction effect. There are different shaped blades used for different purposes. Maybe you now have someone else's blades.

This theory gets my vote. And they may have put a regular blade on where a mulching blade lived before. A sharpened blade that was not balanced in the process could cause irregular cutting as well.

 

[Bud Cline]

And they may have put a regular blade on where a mulching blade lived before.

Zactly my thinking.

 

[95025]

I wish the OP would return and let us know what he found...

First of all, a mower blade not being balanced will not cause it to mow poorly unless the blade is also dull. What it will do is cause the mower to vibrate and, if unbalanced enough, make it shake.

Also, it is highly unlikely that the wrong blade got put back on the mower. Very few mowers have interchangeable blades. Upside down is more likely.


It's possible that the repairman didn't tighten the blade bolt adequately, and that the blade is just kind of free-spinning. He could also have forgotten the washer and, though the bolt is tight, the blade is not. That would also result in the engine never bogging down in long grass.