This one had me stumped for a while…  Johnson J (early, since only serial number was stamped) that runs great out of the water, but has no power and won’t wind up in the water.  Motor doesn’t fire consistently.  So I pulled the mag plate and tested it with an old Stevens tester.  I could hear clicking at the coil, and spark was intermittent.  The tar did not seem original, nor did the screws holding down the coil, so I removed the coil and tar, reinstalled the coil and retested.  Coil would fire on the Stevens, but occasionally arced from the secondary terminal to the mag plate, about half an inch.

I assume I need to replace the tar with something better.  Any help on selection would be appreciated.

Also, can someone tell me why I saw intermittent spark at the Stevens with a gap of 1/8″ and an occasional spark to the plate with a 1/2″ gap?  Seems to me the spark would prefer the gap at the tester, not from the secondary terminal to the mag plate.  (I checked the plug wire, it’s resistance is near zero.)

EDIT / UPDATE:  Even though the coil fired on the Stevens, it was intermittent.  I’ve concluded that the coil is bad and needs to be replaced.

Tom