Several weeks ago, a good friend ame to my home, and said he needed to get his old faithful push mower running again. He said it had no spark, so i instructed him on installing a later model coil on it, and gave him several used but good ones i keep in stock.

He called me later and said it still had no spark! And i gave him several more, and they didn't work either, so i went to his home for a look/see.

Well, no wonder they didn't work! He had installed them upside-down! I put everything a-right, and pulled the rope twice and it ran! No, i didn't rub it in--he's a good friend, and i don't do that anyway!