spark plug issues

[barnfind]

I'm getting a spark from plug threads to cylinder head when testing spark plug- plug is new , what would cause this?
Thanks

[shultz_1978]

Not understanding the question. The spark will jump from the plug to any place it can get ground. It should still spark at the end of the plug. If not you have a bad plug.

Hope this helps a little.

[shinyribs]

^^Exactly. Touch only the electrode to the engine and the spark should jump across the plug as normal,but it will always take the path of least resistance.

[barnfind]

your right it doesn't make sense-sorry. what i meant to say is if you ground the threads of the plug to the fins of the engine i get a spark from the thread of the plug to the fins of the engine not getting a spark in the plug.

[rij1]

If the spark isn't coming off from the center electrode and is coming from somewhere else then it sounds like it has a crack some where. If you dropped the plug it could have cracked. Compare to another spark plug. Its always better to check for spark in a dark area so you can see its path and strength.

[barnfind]

The plugs are brand new from the box. I know I didn't drop one but I'll take a look at each plug. Thanks
For the help !!

[rij1]

I would test different plugs and see how they show its spark compared to the one you are having a problem with. It is with only one plug or all

[barnfind]

I've tried two and same thing, and also weak spark too.

[rij1]

Weak spark? I would start with finding out why that is and worry about your plugs later. Charge up your battery. Is the weak spark from both coils all wires? If its weak off the wires from only one coil then I would think that coil is going out if its weak from all the wires I would think that the battery is weak. there are many other things that could be wrong and cause weak spark. But start with the easiest things to check first..

What year and make of bike is this about?

[barnfind]

Everything is new- points,coils etc. I'll look further into it.
Thanks a lot for the help again.

[rij1]

Make sure you have good grounding.

[barnfind]

Thanks man !!

[TOOLS1]

The SOHC point/coil ignitions do not produce a very hot spark. This is why the Iridium spark plugs make such a big difference in the SOHC engines performance.
TOOLS

[barnfind]

That's what I am running for plugs.

[motogrady]

In the old days, with a 2 stroke, sometimes oil would get in around the ceramic around the electrode,
and spark would travel down the ceramic to the threaded body, bypassing the jump across the gap.

Close the doors, get the place dark, and hold that plug tight against the fins.
If you are seeing a spark from threads to fins you're not holding it tight enough to the engine.
Use a leather or rubber glove if you're getting zapped.

I'd check the plug gap, I have a feeling you are just missing the white spark in the light.

A meter should show nothing from tip of plug that goes into the spark plug wire to threads.
If it does, I'd change to a different plug, see what happens.

[barnfind]

Thanks a lot for the info, I'll check it out.