nissan 9.9 ignition coil

[kyle williams]

hello, I have a nissan NS9.9B2. it was running rough and when I took the cover off I could see the spark jumping from the wire cap past the plug to the block. Running on 1 cylendar. I figured it needed a new wire but on this model the wire is molded one piece with the ignition magento coil. I was told that nissan does not make this part anymore and I found a used one in a boneyard. it ran ok for a few weeks, now it is doing the same thing, on the same wire and plug as before (the lower of the 2 plugs). I found another used one in a boneyard and it is doing the same thing on the same wire. I know it is possible for used parts to all be bad, but it seems too coincidental that the same thing is happening with 3 different parts, (even used ones). Any suggestions for what else may be causing this?

thanks
Kyle

 

[Sea Rider]

Re: nissan 9.9 ignition coil

Had a sililar problem. Was solved by cutting 1/2 cm on both leads ends so to have new cable portions on them and screwing 2 new plug caps. Wrap well with 3 M tape both leads from coil to plug caps, just the straight portions.

One of them seemed to have a small imperceptible crack that caused all the big trouble. To find/detect electrical leaks/arcing would be a good idea to run engine in complete darkness, with water of course. Sometimes old cables starts to have leaks, that's why always wrap them well with tape, just in case.

Happy Boating

 

[pvanv]

Re: nissan 9.9 ignition coil

Also, if you have a bad spark plug (with high resistance), it can be easier for the spark to jump off the wire instead of lighting the plug. Had that on a car once.

 

[kyle williams]

Re: nissan 9.9 ignition coil

hello, thanks so much for your comments. I did consider a bad wire but when it was seen happening on the same wire on the 3 different magnetos I tried, (each magneto has its own wires molded in) I suspected it might be something else. it sure wont hurt to cut and replace as I have nothing to lose!

while trouble shooting I did try 2 different brand-new spark plugs, which are the same brand and vintage as the other cylindar that is not arcing. perhaps a different brand and batch may help.

any other ideas I might try?

thanks again
kyle

 

[Sea Rider]

Re: nissan 9.9 ignition coil

Try 2 new plugs NGK BR7HS10 or B7HS-10 (with or without resistor) gapped tight 1.0 mm and go for a spin. It's not a brand issue as long all are compatible and gapped to original specs.

If having same problem with new plugs and going for new plug's cap, remenber that cable is screwed to interior caps thread pin and factory sealed with glue at the beginning of the cap, so with patience try to unscrew off and cut 1/2 cm of that unscrewed portion.

Happy Boating

 

[kyle williams]

Re: nissan 9.9 ignition coil

I did already try another brand of spark plug, Champions, and they seem to work OK now. gapped as you described. not sure why they work and the NGK didnt, but thanks so much for the help.
cheers
Kyle