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Spark plug lead end thread size - Printable Version

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Spark plug lead end thread size - Erich - 24-03-2018

Hi All,

I apologize if this is a noodle head question. I've a got a supply of KLG spark plugs. I use knurled nuts and blade connectors for my ignition leads. The KLGs I have have some material on the lead end that prevents me from getting the blades tight on the plug with the knurled nuts. So I want to run a die down further so I can get them tight. I have read on the net that the thread is M4. Not on these KLGs. What is the thread size of these. 3BA seems to be close but perhaps not exact. Does anyone know?

Erich in still cold Seattle


RE: Spark plug lead end thread size - Zetomagneto - 24-03-2018

(24-03-2018, 04:09 AM)Erich Wrote: Hi All,

I apologize if this is a noodle head question. I've a got a supply of KLG spark plugs. I use knurled nuts and blade connectors for my ignition leads. The KLGs I have have some material on the lead end that prevents me from getting the blades tight on the plug with the knurled nuts. So I want to run a die down further so I can get them tight. I have read on the net that the thread is M4. Not on these KLGs. What is the thread size of these. 3BA seems to be close but perhaps not exact. Does anyone know?

Erich in still cold Seattle

Erich, put a spring washer between the plug, and terminal, it will take up the slack and help prevent the knurled nut from unscrewing.Becaus its under the terminal blade it wont be seen,in othe words spring washer not under the knurled nut.


RE: Spark plug lead end thread size - Erich - 24-03-2018

Zeto, thank you. I've done that but in the interest of simplicity I wanted to reduce the number of elements in the solution. I had also thought of drilling out the threads of the nut but that doesn't totally address the issue. I'm still curious about the thread pitch.

Best,

Erich


RE: Spark plug lead end thread size - Austin in the Shed - 24-03-2018

Green spark plug co list nuts in M4, 2BA and UNC, Will try and check what UNC if I have a suitable plug.


RE: Spark plug lead end thread size - Erich - 25-03-2018

Hi Dave,

I've confirmed the threads are not M4, nor 2BA, I tried a couple of UNCs but those didn't seem to work either.

On a similar note(dizzies) I've seen both a DJ-4 listed and a DJ-4A. Does anyone know what the differences are?

Erich in Seattle