1990 40hp evinrude arcing

[thurmank]

Motor ran great earlier in summer. Took to lake a few days ago and it started ran long enough for me to get off trailor then died. Would start and run for a few seconds then die after that. Thought fuel problem so I replaced lines and bulb and checked filter. Still not better. Check compression and it was one cyl. At 120 and one 115. While doing this at night I noticed it was arcing completely around both plugs at the boot and at the coil. Replaced plug wires and plugs and it was not as bad but still arcing at plugs and coil. I was wondering if anybody knows what would cause this. Any help would be appreciated.

 

[Bosunsmate]

Is the coil arcing?
If they have cracks they do that
is there any water leak from the water jacket, ay moisture there will cause arcing.
How do the new plugs look? Very oily/ black?
Perhaps somethings happening in the cylinders and making them arc out in the boot area instad

 

[thurmank]

Figured out one carb is not letting enough gas into top cylinder. Bought kits to rebuild them both. Would that cause the problem.?

 

[Bosunsmate]

Not the arcing.
For some reason the electricity is finding it easier to jump across the gap from the boot to the side of the outer head cover instead of just doing the small jump in gap at the spark plug end.
Have you looked at the plugs?
Beats me, have you looked at the threads in the sparkplug holes, not rusted, and no one put gasket goo on them or something very odd?

 

[thurmank]

Nothing in plug holes. Going to get champion plugs instead of ngk plugs. Was told they do not work well with evinrudes. Ordered new coil also but just hoping this fixes it. Any other suggestions?

 

[thurmank]

Yes the coil was also arcing.

 

[Bosunsmate]

Nothing in plug holes. Going to get champion plugs instead of ngk plugs. Was told they do not work well with evinrudes. Ordered new coil also but just hoping this fixes it. Any other suggestions?

not me, but if you put up a link to a youtube video of it im sure i or someone else may think of something