Anyone ever used this spark plug tool?

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Found this in a box that came from my Grandfather, probably 7-8 years ago. Anyone ever used these?

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How so? Its just a pass through - you put the boot end on your plug and the coil end on the shiny part. Its for small engines?
A real spark tester like an ST-125 tester takes 25000 volts to fire. Engine running at idle you may have 8-10k volts, maybe more maybe less depending on vehicle because idle or 2500 in the bay is not a high ignition load condition. The issue is that, while that tool not lighting indicates there is an ignition system issue, you may still have an ignition system issue if it does light. Same goes for an injector noid light.
 
There is a great use for this. It’s when your lawn mower won’t start and you just want to check if it’s getting spark. Just pull the spark wire, plug into metal part and place the rubber boot part the spark plug of the mower. It will light up if it’s getting spark. I actually bought one a few years ago.

It’s especially useful in a snow blower with an electric starter. It lights up like the Fourth of July!
 
A real spark tester like an ST-125 tester takes 25000 volts to fire. Engine running at idle you may have 8-10k volts, maybe more maybe less depending on vehicle because idle or 2500 in the bay is not a high ignition load condition. The issue is that, while that tool not lighting indicates there is an ignition system issue, you may still have an ignition system issue if it does light. Same goes for an injector noid light.
Its not for that. Its for a lawnmower or whatever - so you can install it and pull the recoil starter to see if there is spark at all. Because its really hard to hold the spark plug grounded to the engine with one hand, and pull the starter rope with the other, and still be close enough to see it spark.
 
Its not for that. Its for a lawnmower or whatever - so you can install it and pull the recoil starter to see if there is spark at all. Because its really hard to hold the spark plug grounded to the engine with one hand, and pull the starter rope with the other, and still be close enough to see it spark.
That inline tester is marketed for more than just small engines. Read the description https://www.harborfreight.com/in-li...6OWGBx0cL-c1OiQIMlNXu4Uy-vXeznVRoC8scQAvD_BwE
 
That inline tester is marketed for more than just small engines. Read the description https://www.harborfreight.com/in-li...6OWGBx0cL-c1OiQIMlNXu4Uy-vXeznVRoC8scQAvD_BwE
I don't really care what the harbor freight marketing department thinks there for. I have used them. First time probably 40 years ago. Really they shouldn't be called a spark plug tester - there more a coil tester. 🤷‍♂️

Very handy.

Edit. Here is one directly from China. Even the Chinese know what there for? https://www.ebay.com/itm/3659257120...atarget=&abcId=10414378&merchantid=5639388691

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I don't really care what the harbor freight marketing department thinks there for. I have used them. First time probably 40 years ago. Really they shouldn't be called a spark plug tester - there more a coil tester. 🤷‍♂️

Very handy.

Edit. Here is one directly from China. Even the Chinese know what there for? https://www.ebay.com/itm/3659257120...atarget=&abcId=10414378&merchantid=5639388691

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since when does a lawn mower have a distributor and 4 cylinders like the pic on the back?
 
since when does a lawn mower have a distributor and 4 cylinders like the pic on the back?
Dude I don't know what your issue is. Did one of these testers wrong you somehow?

If someone drew a picture on the back of it being used as a probe for your ear would you use it for that also?

The rest of the world uses it for small engines and find them quite useful.
 
I actually used one of those about a year ago to diagnose a Honda pump mounted on a tanker that would run about two minutes before sputtering and dying. After being certain the symptoms were consistent with a fueling problem and buying a replacement carb which didn't help, and then paying twice as much to buy an OEM Honda carb which didn't help, I spent $5 on one of those gadgets to discover the ignition switch was losing conductivity after the engine ran a couple minutes.
 
Its not for that. Its for a lawnmower or whatever - so you can install it and pull the recoil starter to see if there is spark at all. Because its really hard to hold the spark plug grounded to the engine with one hand, and pull the starter rope with the other, and still be close enough to see it spark.
You got that right…been there done that!
 
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