fastjeff
Gold Medal Contributor
"Well, I really screwed up. Wa
"Well, I really screwed up. Was comparing the tach in my boat with a Tiny Tach, to calibrate it. Not getting a decent readings from the Tiny Tach, I got some aluminum foil to place over the other ignition wire and shield it from EMF interference. I've doen this before and it worked great, but I wrapped it tightly around the wire, not draped it over it.
Guess what? The EMF charged foil touched against the low voltage terminals of the ignition coil and blew out a perfectly good spark box. Damn and double damn! I watched the boat tach slowly drop to zero rpms with the motor still running--barely--and then it went away totally. No spark.
We live and learn...
Jeff
PS: Anyone out there havew a spark box for a Merc 25 (mid-80s) that they want to part with?"
"Well, I really screwed up. Was comparing the tach in my boat with a Tiny Tach, to calibrate it. Not getting a decent readings from the Tiny Tach, I got some aluminum foil to place over the other ignition wire and shield it from EMF interference. I've doen this before and it worked great, but I wrapped it tightly around the wire, not draped it over it.
Guess what? The EMF charged foil touched against the low voltage terminals of the ignition coil and blew out a perfectly good spark box. Damn and double damn! I watched the boat tach slowly drop to zero rpms with the motor still running--barely--and then it went away totally. No spark.
We live and learn...
Jeff
PS: Anyone out there havew a spark box for a Merc 25 (mid-80s) that they want to part with?"