I did that with the battery but it took a while for it to light up. I'm using NGK 6926 supposedly "rapid start". There is continuity tip to tip, then I touched the tip to the threads and there is continuity, "weird". I get 00.0 at the 200k ohm setting so I went as low as my meter could go which is 200 and it read 00.8 .
Why the continuity from tip to threads? The machine is hard to start, white smoke, missfiring for a little while after it starts, all the symptoms of bad glow plugs. At $8.99 each , probably start with free batch.