Premature sparkplug death: Odd

[ty998]

Bike '81 GS 650 G

Started bike and it sounded odd. After a quick inspection one of the cylinders was not firing. After another quick test I found that the sparkplug in cylinder 4 was not sparking and any other plug sparks connected to #4 boot. This was a new (3 months old) NGK spark plug. Is this of any particular concern or do plugs randomly do this? Plug looked good and gapped correctly.

[Guest]

If other spark plugs didn't fire on the same plug wire, it's probably not the plug, but the cap, wire, or coil.
Try this, unscrew the cap off, cut a section off the end of the wire, about 3/8" and screw the cap back on after cleaning the inside of the cap as to have a good conductive surface free from dirt, adhesive, grease, etc.

[razor02097]

He said other spark plugs spark on that wire.



Once I dropped an NGK spark plug it hit concrete but appeared completely undamaged (actually it was still in the package). I adjusted the gap and installed it. That exact plug failed within a few weeks. Just as you describe no spark at all...coincidence? Might be what happened to you. Even if you didn't drop it unfortunately it would be hard to prove a shop did and most shops aren't going to replace it.

I wouldn't worry too much and just replace it.

[bbjumper]

Just to be clear, no spark from any plug in the #4 position?

[MisterCinders]

No. The OP said no spark from that plug, but other plugs on that lead sparked.

[Guest]

No. The OP said no spark from that plug, but other plugs on that lead sparked.

I think I got it right for once.

[rustybronco]

After a quick inspection one of the cylinders was not firing. After another quick test I found that the sparkplug in cylinder 4 was not sparking and any other plug sparks connected to #4 boot.

You need to clarify what you are attempting to convey.

[BigD_83]

Bike '81 GS 650 G

Started bike and it sounded odd. After a quick inspection one of the cylinders was not firing. After another quick test I found that the sparkplug in cylinder 4 was not sparking and any other plug sparks connected to #4 boot. This was a new (3 months old) NGK spark plug. Is this of any particular concern or do plugs randomly do this? Plug looked good and gapped correctly.

Does the original plug spark when installed in another boot?

[razor02097]

After another quick test I found that the sparkplug in cylinder 4 was not sparking and any other plug sparks connected to #4 boot.

Any other plug plugged into 4 will spark. Right? Seems pretty clear to me.

[ty998]

Let me clarify:

-The spark plug in #4 boot was not sparking.
-Other plugs connected to #4 boot sparked.
Hence the SP was the problem.

I was wondering if this was due to a larger problem or just the plug.
From 'Razor02097's respone it seems this has happened with other plugs and is not a system problem, but simply a defective plug.

Just odd having a plug quit so early. I have never seen that before.

[BigD_83]

I had a brand new plug, straight from packaging, give up the ghost within a week. Odd, but not unheard of.

[Guest]

I think I got it right for once.

Well, maybe not.

[earlfor]

Let me clarify:

-The spark plug in #4 boot was not sparking.
-Other plugs connected to #4 boot sparked.
Hence the SP was the problem.

I was wondering if this was due to a larger problem or just the plug.
From 'Razor02097's respone it seems this has happened with other plugs and is not a system problem, but simply a defective plug.

Just odd having a plug quit so early. I have never seen that before.

I have had a few plugs that were faulty right out of the box and others that went bad in a few days, so getting a bad one isn't unheard of.

[Guest]

I have had a few plugs that were faulty right out of the box and others that went bad in a few days, so getting a bad one isn't unheard of.

You and me both.