Mower Problem. Running Rough


Old 09-13-01, 01:26 PM
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I am having a similar problem as this poster:

I hit a large rock that I didn't see in the high grass. It bent the blade so bad it caused the engine to stop.

I went to the store and bought a new blade and but it on. It didn't start up right away but it did eventually start. Had some smoke (White I think). It runs now but it sorta sputters, like the timings off or something. I mowed my whole yard today. It doesn't seem to have the power it once had. Other than the sputter and lower power, it seems fine.

Any help?

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Old 09-13-01, 02:05 PM
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Hello: Punisher

When the blade struck the rock, the engine came to an abrupt halt but the flywheel didn't. It must have bent the keyway. If the engines just runs rough and doesn't vibrate with the new blade, the crankshaft may be okay.

The keyway is the part that secures the flywheel to the crankshaft. To access it you'll have to remove the flywheel and replace the keyway with an exact duplicate replacement.

The flywheel is a cast type metal and can break very easily. A small engine flywheel puller is the only tool that can assure removal without breakage.

If a puller isn't available, it would be very risky attempting to remove it any other way.

Once it is removed, look closely at exactly how the current keyway is installed. Replace it with a new exactly as you found the existing one.

In some cases, the electronic magneto does not have to be removed first. If it does on your machine {engine brand unknown} mark the exact location of the magneto.

Replacing the magneto on Briggs engines is easy. Setting the air gap between the flywheel and magneto is about the width of a business card. The archives within this forum have several postings on that topic.

Tecumseh engines can be air gapped also but often not to accurately. These engines require a dial gauge to accurately set the timing. Do the best you can to avoid removing the magneto on Tecumseh engines.

Regards and Good Luck,
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Old 09-13-01, 02:10 PM
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Appreciate the info. It's a murray by the way.

It sounds as though this is something I can do myself. Is that correct?
Old 09-13-01, 03:42 PM
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Hi: Punisher

Murray. Great. Murray uses Briggs engines.

Yes. You can do this yourself. Just use caution removing the flywheel if your not using the proper sized puller.

The flywheel can be removed with a little gentle prying on each side and equally around the entire circumferenace in small amounts at each try and location.

The idea would be to ease it up little at a time, if possible. DO NOT use the engine case as a leverage point for the pry bar or long bar. The engine case is made of aluminum or pot metal and also breaks easily.

To reinstall the flywheel, set it on the shaft first and carefully tap the new keyway into place. Be sure the keyway is installed correctly between the crankshaft and the flywheel.

When you get this project completed and the engine running again, locate this orginal topic, click reply and update the forum with the results. Always nice to find a reply to a project repair successfully completed....

Regards and Good Luck,

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