Spark jump at coil...

[1975 Mercury 65 3Cyl 650]

I am getting a spark jump from the right side body of the coil to the aluminum housing. I have removed the coil and checked for cracks in the insulation and found none. Engine runs fine until it starts arcing. I have tried wrapping it tightly with electical tape to insulate it and it seems to have helped a little but still getting the spark. Looks like a new coil is big $$$, so I would prefer to repair instead of replace if possible, since it otherwise works well. Is there a good way to insulate the coil to eliminate the spark jump?

 

[tmcalavy]

Re: Spark jump at coil...

Try a couple of coats of liquid electrician's tape.

 

[jmoorepghpa]

Re: Spark jump at coil...

Radio Shack should sell phenolic board for making custom circuit boards. You want the kind that has no conductor laminated to it just plain old phenolic board. Try cutting a piece of that an placing it over the suspect area and like tm said coat with some liquid e-tape. I would really suspect you should start looking for a coil though. If you do try to patch it don't be surprised if the thing quits on you at some point.

 

[I/O WALDO]

Re: Spark jump at coil...

Does the plug wire have high resistance?(aka open plug wire)

 

[jmoorepghpa]

Re: Spark jump at coil...

Looking at the picture closer seems like there is a LOT of water on and around the coil. If that is water, dry it off and how is it getting that wet? And what Waldo said too.

 

[studlymandingo]

Re: Spark jump at coil...

I have a neighbor with the same motor. His coil is covered in silicone (the GE clear type) for just the same reason. I asked him about it last year, he said that was the fix he did a couple of years before. I guess it does the trick.​