Why does my wire keep popping off my spark plug!?!?

[WillieL]

Hey i got a 1993 blaster it has been running perfect for the last year or so and today i took it out and started riding it and after about 20 minutes of riding my spark plug cap just popped off. the big bogged off and then i popped it back on it started right up. then i rode for about a minute and it happened again. then again. then again. until i got home. then i checked it out. didn't see anything wrong. so i let it run revved it a little bit and then looked down and the cap was barely on. i hadn't even moved? Some body help!

 

[yamaha28]

could be that the metal piece inside the cap is worn down or got bent so it's not tight on there. I might have an extra coil that I can send you, you just pay shipping

 

[blasterdemon7]

Try putting the plug boot all the way

 

[Larry's Shee]

On some plugs the end is threaded on, is yours missing the "nub" that threads onto the plug? It might be inside the boot. Or not, LOL

 

[blasterboy32]

If the top is still on the sparkplug then I would try bending the metal piece that is in the sparkplug boot to make it a tighter fit. That should keep it from sliding off so easily. Or if you want another temporary fix just so you could ride it a little bit of electrical tape could hold the boot to the sparkplug

 

[Paulie B]

I've used a set of vice grips on the boot to crush the opening down a tad. Then its a tight fit again. That is assuming the boot being worn out is your problem.

 

[scotj77]

or buy a 5 dollar cap to replace it. I dont' like the ones that slide onto the threads. I had and ngk one and it wore out quickly. not made for constantly being taken off to check the plug I guess. go withthe soft rubber factory style and you will be good to go

 

[DirtDiggler]

Crimp down the contact and put some grease on the plug , the grease will keep it from corroding and just shove hard to get the contact over the plug . Another thing you can do is poke a small hole in the rubber cover of the plug wire , as the engine heats up the air trapped in the plug boot heats up and expands and can cause a loose fitting plug wire to pop off while riding . Seems kind of implausible I know BUT Honda cars used to suffer from the same problem , their deep spark plugs buried inside those OHC heads have long plug boots and they figured out they had to add a hole to vent the hot air from them . The super heated air , combined with the vibration of the engine can cause it to pop off .