Checking for spark on mag. ('39 B)

Thanks
Chris Horn
Scappoose Oregon

• Hobby farm

It won't burn any holes in your paint but you do need to ground the plug in some way. You need to find a ground area that is free from paint. I usually take out all four plugs just to make it easy to crank the engine over slowly. Use the #1 plug and plug wire and either lay the plug on the mag body such that ground contact is made or use a wire with clips to get a decent ground to the plug from someplace. I wouldn't hold the plug in your hand or you could get a surprise :). If you are not going to check the timing at the same time in the inspection opening, then there's no need to pull all plugs, just any one on them to only check for spark. Just remember that there are only two mag snaps (plug fires) per crank revolution so depending on where you start you could have three duds before you see a fire. Go through a complete two crank revolutions to be sure.

Rod