Export thread

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

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

7394 said:

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

Click to expand...

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

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.

ILENGINE said:

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.

Click to expand...

Thanks.

jm123 said:

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

Click to expand...

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.

reynoldston said:

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.

Click to expand...

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?

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

bertsmobile1 said:

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

Click to expand...

Thanks.

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.

reynoldston said:

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.

Click to expand...

The battery arcing?

Any positive wire or electrical fitting to the negative side makes for sparks. The frame of the rider is a very big negative wire and very east to make a short circuit. Not so bad working on mowers but the modern cars with the computers it can cost big $$$'s. Just a habit I got into with the many years of doing this type work. Just the small job of disconnecting a battery cable can save you many hours of work if a small mistake is made. We all get habits good or bad I guess. My wife tells me this all the time when I pass gas in the evening.

reynoldston said:

Any positive wire or electrical fitting to the negative side makes for sparks. The frame of the rider is a very big negative wire and very east to make a short circuit. Not so bad working on mowers but the modern cars with the computers it can cost big $$$'s. Just a habit I got into with the many years of doing this type work. Just the small job of disconnecting a battery cable can save you many hours of work if a small mistake is made. We all get habits good or bad I guess. My wife tells me this all the time when I pass gas in the evening.

Click to expand...

lol

I was under the impression all walk behind mowers were killed by grounding the mag so what would be the purpose of disconnecting the plug.

Mentioned; on my riders I do disconnect the neg batt cable but for other purposes than accidental starting and the C-clamp makes that a snap. The neg clamp even gives me a place to hide the key from the grand kids.

SeniorCitizen said:

I was under the impression all walk behind mowers were killed by grounding the mag so what would be the purpose of disconnecting the plug.

.

Click to expand...

Yes you are 100% right. It takes all of 1 second in time to pull the wire off the plug and as I said earlier its more a habit then anything. I also have a wood work shop and I unplug the saws before I change the saw blades even if the switch is off. Everybody has a idea of what is safe or not. I just picked up a lot of these safety ideas when I worked for a large manufacture and it just becomes to be a habit. Is this bad or good??? As I seen in one of your earlier post you worked with large equipment I will bet your had to think safety doing that type of work.

SeniorCitizen said:

I was under the impression all walk behind mowers were killed by grounding the mag so what would be the purpose of disconnecting the plug.

Mentioned; on my riders I do disconnect the neg batt cable but for other purposes than accidental starting and the C-clamp makes that a snap. The neg clamp even gives me a place to hide the key from the grand kids.

Click to expand...

and are you absolutely sure it has not moved up just a tad ?

bertsmobile1 said:

and are you absolutely sure it has not moved up just a tad ?

Click to expand...

I suppose nothing is for sure except taxes and death but why worry about everything little that could happen.

reynoldston said:

Yes you are 100% right. It takes all of 1 second in time to pull the wire off the plug and as I said earlier its more a habit then anything. I also have a wood work shop and I unplug the saws before I change the saw blades even if the switch is off. Everybody has a idea of what is safe or not. I just picked up a lot of these safety ideas when I worked for a large manufacture and it just becomes to be a habit. Is this bad or good??? As I seen in one of your earlier post you worked with large equipment I will bet your had to think safety doing that type of work.

Click to expand...

Sure did, but when the flywheel needed to be blocked to keep an engine from rotating when inside the crankcase doing bearing work that wasn't being concerned with little things. Those were big things to be concerned about. :laughing:

SeniorCitizen said:

Sure did, but when the flywheel needed to be blocked to keep an engine from rotating when inside the crankcase doing bearing work that wasn't being concerned with little things. Those were big things to be concerned about. :laughing:

Click to expand...

So big you wouldn't even feel a thing or worry about the ER.:frown:

So far (knock on wood) I still have my (original equipment) 10 fingers, but have burnt them, broke them & smashed them & had bad cuts on them.. I've gotten kinda used to em in 60 years, so trying to keep em around. :thumbsup:

7394 said:

So far (knock on wood) I still have my (original equipment) 10 fingers, but have burnt them, broke them & smashed them & had bad cuts on them.. I've gotten kinda used to em in 60 years, so trying to keep em around. :thumbsup:

Click to expand...

Very good reason to take the 1/2 second in your busy day to remove the plug wire.

The new B & S ready start engines and the DOV engines start so easy that safety has to be a concern.

The Snapper pedestrian mowers brought out a few years ago had a wrong sized OPC cable and would not switch off which meant that it could start at any point.
We mannaged to start one with about 3-4 inches of rope.

Also when servicing an engine and you remove the oil then reomove the spark plug so it cant be started.
Iv heard so many cases of seized engines due to people not doing this.

If you come to an engine and the plug or lead is off then alarm bells ring so to check oil level and petrol level and not just try to start it.

For those still wondering why the concern picture the WWI aircraft starting procedure shown in films. Tractor hot, key left on, rotating blades under deck to remove...ouch. A 12V battery is a potential arc welder which can be seen once the terminal is accidentally grounded to sheet metal . Wrenches laying loose are bad for this. I think I have one with "weld" spatter on it.:confused2:

reynoldston said:

Very good reason to take the 1/2 second in your busy day to remove the plug wire.

Click to expand...

Indeed Sir..

I read years ago that removing the plug wire warning was brought about because of a law suit against Huffman Mfg. Co. Look at most of the old Huffy lawnmowers and riders and if you tip the mower on it's end for servicing the blade etc. The spark plug most always pointed down and apparently made the mower easier to start accidentally. I think there is a CPSC regulation about the location of the sparkplug on mowers? Still a good idea to disconnect though!