Hey guys. I bought a spark plug tester today to use on my DT 100 and found I can't use it. It uses the standard terminal lug, like an automotive application. It will not plug into the smaller plug wire on the bike that is designed for a threaded terminal stud. Unlike most spark plugs, the end on the tester is not designed to unscrew. Every spark plug tester that I've looked at is the same way.

Does anyone know of a spark plug tester that will work with a motorcycle's threaded stud?

I think most of us use the spark plug... you won't get a huge spark out of that system and kicking speeds. Plug gap is 0.020" to 0.024" and spark might not be seen in bright light.

Most likely cause for no spark on a bike that's been sitting is simply oxidized point contacts... fine emery cloth and some contact cleaner... then draw strips of white uncoated business card through the contacts until they come out clean.

Sorry Glenn, but I do have to say....
Most of us here, use our bikes, AS spark plug testers.
But Cool, non the less. !

Apologies if I've misinterpreted the question (what, you Al, I hear you all cry?! ), but those little screw on caps come with all new NGK plugs and, if not needed, are removed and discarded. Therefore buy yourself FROM A VERY REPUTABLE SOURCE (ie not a cheapo one off ebay, as there are lots of fakes out there) a new one or two (you will need them at some stage in the future), remove the threaded cap, attach it to your old plug and test.

This is a very good tool to check if the plug is actually making a spark. But it won't tell you what is wrong if it does not make a spark. They have been hard to find lately. I got 3 of them about 3 years ago from a supplier in Australia.

That check spark tool looks pretty handy!

I did find this on Amazon... an adjustable gap tool. Looks like it has the small threaded post.

www.amazon.com/Toolso-Adjustable-Ignitio...ostic/dp/B07L1879ZG/

Yes, my son and I were doing the same thing. But we were having so much trouble with getting a spark we decided to get a tester to make things easier. Guess it didn't work.

Pulled the flywheel off yesterday and found that the (original?) points were very worn. Got some on order. Hopefully that will FINALLY get things moving.

Even though the points will be new, they may have picked up a slight film on the faces whilst in storage, so still do the white card pull through clean that MarkT suggested earlier.

Hey Glenn, Did you do any frame painting?
Clean/ sand your " Grounding : points on the frame?