Condenser or Coil?

Fast Pat

Cadet
Joined
Aug 4, 2008
Messages
9
Just bought a 9.5 Johnson with no spark on lower cylinder during a spark test (1/4" gap). I can get a spark to jump a 0.030" gap. Would this be the condenser or coil? The points assembly looks new.
 

tx1961whaler

Vice Admiral
Joined
May 31, 2008
Messages
5,197
Re: Condenser or Coil?

How old is the motor? If it's old, then probably the coil is shot. I tend to overkill and replace the whole setup (both coils, points, condensers,plugs, wires) when I get an unknown engine, just so I have a good baseline to deal with. If one coil has failed and they are both the same age, then the other one will fail, on the water, as the sun is going down and the wind is blowing 20 mph in your face. It costs a few bucks (125-150) to get the ignition, carb, and water pump parts, but once you do that you can forget about it and enjoy the motor for a few years without worrying about it.
 

Fast Pat

Cadet
Joined
Aug 4, 2008
Messages
9
Re: Condenser or Coil?

1970 Johnson. One coil looks older than the other. I don't see any obvious cracks but, I haven't removed them.
 

Chinewalker

Fleet Admiral
Joined
Aug 19, 2001
Messages
8,902
Re: Condenser or Coil?

Chances are, if the coils LOOK good, they probably are good. This includes checking the bottoms for arc through. It is rare to get a dead coil that doesn't look the part - but not impossible. Lacking a tester, go with the cheap stuff first... Clean and gap the points to .020". Better yet, install a tune-up kit (two sets of points and condensers).

- Scott
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,195
Re: Condenser or Coil?

If it is sparking .030 but not 1/4" I'm putting my money on either the coil arcing through, or the spark plug wire is arcing through where it is clamped to the bottom on the armature plate. The old electricity rule that says it follows the path of least resistance. .030 is less resistance than 1/4" and a path arcing through the insulation is somewhere in between. Or, of course the coil could have an open secondary winding.
 

Fast Pat

Cadet
Joined
Aug 4, 2008
Messages
9
Re: Condenser or Coil?

You're right. The spark plug wire is arcing where it exits the bottom of the (ignition plate) thingy. The wire gets pinched at closed throttle and it damaged the insulation.

It looks like the wire is routed around the circumference of the plate. But, I can't figure out how to remove the plate to replace the wire.
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,195
Re: Condenser or Coil?

Four screws, probably Phillips head. Two through the coils and two down in between the coils and points. They are "captive" screws, meaning unscrew them till they turn loose of the retainer below, but you don't have to take them all the way out.
 

Fast Pat

Cadet
Joined
Aug 4, 2008
Messages
9
It's Healed!

It's Healed!

I installed new spark plug wires, reset the points and, voila, she's firing on both cylinders. Took her out to the lake and she's never run so fast, 14.5 mph (GPS) on a 14' aluminum flat-bottom. Thank you Chinewalker and F_R! I appreciate your help.
 
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