whole spark plug lit up while bike is running

[stephen7689]

I'm having spark issues my bike runs fine but I can see a lot of spark coming out around pourceline of plug and zapping the boot and if I touch the boot or wire the bike dies right away any idea how to fix this problem or what I did wrong

 

[crassius]

I'm thinking plug has a crack in it, but never hurts to check wire and cap also. On the plus side, at least you know your mag is working : )

 

[zippinaround]

if you still have the kit wire and cap i would change out the lot new plug, wire and cap very cheap to do.

 

[Street Ryderz]

Time for a new plug try a good name brand in the right heat range the ones that come with the engine are garbage!

 

[Frankenstein]

Time for a new plug try a good name brand in the right heat range the ones that come with the engine are garbage!

They are not garbage they are just really really awful and have a bad tendency to fail prematurely for no good reason, but definitely not garbage.

 

[stephen7689]

Plug is new and a very good one I had this same problem with last plug too had to wrap it in electrical tape

 

[crassius]

check whether your cap requires a terminal nut on plug or not

 

[Frankenstein]

check whether your cap requires a terminal nut on plug or not

Yeah it sounds like a boot problem if it's new plug with the same problem.

Curious about how difficult to start? Seems like a strange way for the spark to travel being that you said it runs, meaning it's sparking in the area it is supposed to. Makes me wonder if you have a bad ground from the head, if the spark is indeed happening at the tip of the plug as intended (if it's going from the boot around the outside of the spark plug then it would ground out at the head and not run) then the return path is the part that is to blame, especially if you kill the motor by touching the plug or boot since you changed the return path to ground.

You have a painted motor head by chance? If you have a multimeter try checking the resistance of the motor by putting a probe on the head, and the other on something like an exhaust stud, if you don't get a reading then you don't have a solid ground. If you do get a reading then you might have a really weird wire problem or for all you know a second defective plug.

Just seems so odd for the spark to jump the air gap on the outside of the plug but also successfully spark in the combustion chamber..

 

[stephen7689]

Yeah it sounds like a boot problem if it's new plug with the same problem.

Curious about how difficult to start? Seems like a strange way for the spark to travel being that you said it runs, meaning it's sparking in the area it is supposed to. Makes me wonder if you have a bad ground from the head, if the spark is indeed happening at the tip of the plug as intended (if it's going from the boot around the outside of the spark plug then it would ground out at the head and not run) then the return path is the part that is to blame, especially if you kill the motor by touching the plug or boot since you changed the return path to ground.

You have a painted motor head by chance? If you have a multimeter try checking the resistance of the motor by putting a probe on the head, and the other on something like an exhaust stud, if you don't get a reading then you don't have a solid ground. If you do get a reading then you might have a really weird wire problem or for all you know a second defective plug.

Just seems so odd for the spark to jump the air gap on the outside of the plug but also successfully spark in the combustion chamber..

From what you say I think it's a grounding problem the bike runs while still sparking up the outside of plug and boot I have a very powerful plug in it it's fairly easy to start but doesn't like to stay running till it warms up and I just painted it today so that can't be a problem but I also seen that while bike is running if I adjust idle screw and tap bike frame with the screwdriver while adjusting screw I can see a small spark from the bicycle frame it's self

 

[Frankenstein]

Have a multimeter?