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I was mowing the other day and there was a pipe sticking out of the ground. The pipe wasn't carrying any services, just a piece of metal sticking out of the ground (I've now removed it).

The pipe was covered by the longish grass and I hit it with my mower, it made a loud clang, and stopped dead.

Now the blades on the mower are very hard/stiff to turn by hand. Using the pull starter is completely impossible, the rope would break if I pulled it any harder. I'm thinking the drive shaft may have disconnected with the engine, but I don't really know a lot about small engines.

Some more information. It's a Husqvarna mower, one year old with a Briggs & Stratton engine. The engine is still under warranty, but the closest authorized repair place is two hours from where I live.

I'm wondering if someone has come across this situation before and would know if it's an easy fix or is the mower a write-off.

EDIT:

Thank you everyone for the answers and suggestions. Due to the amount of warnings below, I'll take it to a repair place. If some more information comes in I'll post it up here.

The reason I was thinking about fixing it myself was the support person from Briggs & Stratton gave me a suggestion to buy this Repair Manual

EDIT 2: I didn't take it to a repair place and trying myself. So starting to take it apart (spark plug is out) and get the top cover off. The main wheel that turns with the blades can rotate 2 full turn freely and then for the next 1/4 turn it is very tight, then repeats.

EDIT 3: Success! After spinning the wheel and blades a bit more everything seemed to loosen up and now it's working! Turns over with one easy pull of the rope.

EDIT 3.5: Because if all the interest and concern over the pipe, see photo. It was well inside my property line and I assume it was once used to hold a flag or sign.

PIPE

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  • 11
    Disconnect the spark plug wire and check the mower blade for any obstructions. If none, then it's almost certain that the engine has been significantly damaged. You can try to file a warranty claim but chances are that it will be denied since the signs of "abuse" will be obvious
    – jwh20
    Commented Jun 24, 2019 at 12:37
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    @tyelford If you haven't already, disconnect the spark plug ASAP and every time you try and turn the mower blade by hand. The mower blade is directly connected to the crank-shaft of the engine and (were it capable of doing so) turning it might cause the engine to engage, kind of like the old airplane props you've seen.
    – Sidney
    Commented Jun 24, 2019 at 14:15
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    If you don't know how to fix it, please don't try to DIY it. Send it to a professional. I knew a guy who tried this and nearly killed dozens of people. He decided that "just bending [insert part name here] back into position" would be OK. While he was cutting some grass, one (or part, not sure) of the blades went flying off and cut clean through 4 cars and took out the rear passenger window on the 5th car. Miraculously no one was hurt, there were 40-60+ people walking where he was cutting. He was ordered to pay the equivalent of about US $70,000 in damages + fines.
    – Malekai
    Commented Jun 24, 2019 at 15:41
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    @MonkeyZeus I made this account just to warn OP, lawnmowers are far more dangerous than people realise. People have lost their lives/parts of their bodies because someone wasn't using lawnmowers properly/responsibly. It's literally a blade spinning at hundreds (if not thousands) of RPM.
    – Malekai
    Commented Jun 24, 2019 at 15:48
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    Anybody else come here just to see whether it was the pipe or the mower that wouldn't turn?
    – A C
    Commented Jun 25, 2019 at 21:30

5 Answers 5

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This sounds like that impact has bent the crankshaft, which means that the engine will either need replacing or to be rebuilt.

You need to decide whether a 2 hour drive to get a quote with the waiting for repairs to be completed is worth it or just to buy a new one....

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    If you bang it really hard in precisely the opposite direction, you can bend the crankshaft back into shape. The chances of this working are really low.
    – Sentinel
    Commented Jun 27, 2019 at 10:09
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    @Sentinel there is a 99.99% chance of making it worse with your idea...
    – Solar Mike
    Commented Jun 27, 2019 at 10:12
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    Worth a shot. His mower is fecked anyway.
    – Sentinel
    Commented Jun 27, 2019 at 10:15
  • @SolarMike he did say "precisely"...
    – simpleuser
    Commented Jul 4, 2019 at 15:51
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Check for a sheared flywheel key. It connects the flywheel to the crank shaft and it's designed to break with less force than it would take to cause permanent damage to the engine. Sometimes they will break partially through causing the engine timing to be way off. It would cause symptoms similar to what you're describing.

Once you get it running again be sure to check the blade for damage. It could be dangerous mowing with a bent or otherwise damaged blade.

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    I wouldn't think a dinged key would cause the engine to be hard to turn over. It should turn over but (probably) not fire. This sounds like the key didn't do its job and something got bent. But note @dinorich's answer too...
    – Bob Jarvis - Слава Україні
    Commented Jun 24, 2019 at 17:45
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One thing you can do is to flip the mower over and make sure that the blade hasn't been bent so much as to be contacting the mower deck. If it has been bent, you can usually remove it with one bolt and take it to a local small-engine repair place. They'll be able to unbend a bent blade for you, or at least sell you a replacement.

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    One should use caution flipping over a gas mower, right? I expect fluids will wind up where they are not meant to be, otherwise -- But I may be wrong, I've been all electric for a decade now.
    – Saiboogu
    Commented Jun 25, 2019 at 18:16
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    Thats' true. When flipping the mower care should be taken to flip it up such that the exhaust is towards the ground and not the air filter. Otherwise, you might have fuel leaking through the air filter.
    – Paul Belanger
    Commented Jun 26, 2019 at 12:46
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This exact thing happened to me last year (Husqvarna mower, long grass, hit a pipe, clang, mower stopped, cord stuck) and it was a bent blade. Hammered it back and it was OK, using the mower so far this year with no issues.

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    Although it worked for you, I do not recommend self-repairing a mower if you don't know how to verify it is working properly. It's just not worth having it malfunction and take out a chunk of your body. Better get it looked at.
    – Nelson
    Commented Jun 24, 2019 at 14:39
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    Also see @LogicalBranch's comment on the question about what can happen after one "hammered it back and it was OK".
    – Earthliŋ
    Commented Jun 24, 2019 at 19:52
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    Link for those who can't find it.
    – Malekai
    Commented Jun 25, 2019 at 12:15
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I agree with others' comments about electric mowers. (not battery; with a cord). I had one for 15 years, and only ran over the cord twice. (not the end of the world, you buy a new cord, and try to be careful).

As far as this one goes: carefully heed the advice about pulling the spark-plug wire!

Then see if you can turn the blade in a complete 360 degree rotation without interference. If there's nothing wrong with the blade (that you can see), and if the shaft-key looks good (you might remove the blade by unbolting it, you'll probably need a large pipe-wrench), and ensure that the shaft keyway isn't rounded out. (if so, the blade would spin independently of the shaft). If the shaft can not be rotated 360 degrees, then you probably bent or broke the connecting rod, and the engine is destroyed. But I don't think that's likely to have happened in this case. (it could happen though).

Many newer motors have an aluminum blade, and if the blade is damaged, you'll need to buy a whole new blade. Repairing an aluminum blade usually doesn't work very well. Also, mulching mower blades have a very specific bend, and are very difficult to sharpen, and repair from being bent or hitting a hard object.

I think: most likely, you have damaged the blade.

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  • Hello, and welcome to Home Improvement. Thanks for the answer; keep 'em coming. And, you should probably take our tour so you'll know how best to contribute here.
    – Daniel Griscom
    Commented Jun 26, 2019 at 1:16
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    Many newer motors have an aluminum blade Do you have a reference or example for that? I've never heard of an aluminum blade and can't find any examples.
    – dwizum
    Commented Jun 26, 2019 at 17:49

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