Why disconnect spark plug when servicing?

[jm123]

I've seen this recommended in a number of places. Wondering why.

 

[7394]

Safety, of course.. On a push mower (for example) if you bumped the cutting blade, it could start up & possibly chop off yer arm..

 

[jm123]

Safety, of course.. On a push mower (for example) if you bumped the cutting blade, it could start up & possibly chop off yer arm..

That would be a manly bump. Has anyone ever seen/heard of this happening?

 

[ILENGINE]

I think this is left over from years gone by, when engines had true mags. I had an old Wisconsin 7 hp that had a mag, and you could turn the flywheel by hand and you would hear a click. That click was a full power spark, so it was possible to bump start this engine.

 

[jm123]

I think this is left over from years gone by, when engines had true mags. I had an old Wisconsin 7 hp that had a mag, and you could turn the flywheel by hand and you would hear a click. That click was a full power spark, so it was possible to bump start this engine.

Thanks.

 

[reynoldston]

That would be a manly bump. Has anyone ever seen/heard of this happening?

I agree I have never seen or heard of anything happening. I am sure going to disconnect the plug if I am handling the blade under a push mower for what little time it takes. Do what you like because if by chance something did happen when you are working on it I wouldn't feel a thing or even know about it. We all have a different idea on safety and its not fun sitting in a ER.

 

[jm123]

I agree I have never seen or heard of anything happening. I am sure going to disconnect the plug if I am handling the blade under a push mower for what little time it takes. Do what you like because if by chance something did happen when you are working on it I wouldn't feel a thing or even know about it. We all have a different idea on safety and its not fun sitting in a ER.

I agree. Having good medical insurance doesn't mean that I want to use it. Just trying to understand *why* it is recommended. Old wives tale? Ladder warning sticker syndrome?

 

[bertsmobile1]

Never had one actually start but every now & then one will fire if it has a combustable mix in the chamber.
for the same reason I generally pull the plug most of time I will be pulling it out in any case and even a back spin off compression can nip the tip of a finger

 

[jm123]

Never had one actually start but every now & then one will fire if it has a combustable mix in the chamber.
for the same reason I generally pull the plug most of time I will be pulling it out in any case and even a back spin off compression can nip the tip of a finger

Thanks.

 

[reynoldston]

Another habit I have is disconnecting the battery cable on a rider before working on them. A wrench in the wrong place makes for sparks.