spark plug popped out of block! help!

16 replies to this topic
  • mxkid23

Posted October 16, 2010 - 11:18 PM


Ok so another day at the track and my bike stalled I take it back to the truck to see that the coil is about a inch and a half popped up. I pulled it out to find my spark plug with no threads what so ever! Does anyone have and idea why this would happen? Now I have all the threads stuck inside of the motor. is my yz450 putting out this much compression that it popped the plug out? Could the plug be deffective? Something or anything? Please help me out!

  • grayracer513

Posted October 17, 2010 - 08:49 AM


If you are saying that the threaded section had broken off the plug, then you need to take it to a shop that can remove it with a screw extractor ("easy-out"). Otherwise, I'm not really sure what you're talking about.

  • mxkid23

Posted October 17, 2010 - 07:21 PM


Yea that's exactly what happened..but what caused it?

  • grayracer513

Posted October 17, 2010 - 07:46 PM


The person installing the plug mishandled it. If you're lucky, the threads in the head will be OK. Go have someone remove it. If you consider yourself competent with a screw extractor, and you have one the right size, do it yourself.

  • mxkid23

Posted October 18, 2010 - 04:46 AM


I install all my plugs never has this happened

  • grayracer513

Posted October 18, 2010 - 07:02 AM


You mean it's never happened before :excuseme:

  • mxkid23

Posted October 18, 2010 - 09:18 AM



  • Z06PSI

Posted October 18, 2010 - 09:20 AM


Overtightened. Some spark plugs are two piece at the thread level. Or it just failed.

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  • mxkid23

Posted October 19, 2010 - 06:46 AM


i contacted ngk they said to send reciepts along with the plug. who knows how long that will take!

  • aedwards07

Posted October 19, 2010 - 06:54 PM


So they are sending you a new $4 spark plug?

  • tech24

Posted October 20, 2010 - 05:28 AM


is the hex part of the plug that the socket goes on still in the head? I'm a little confused, first reading it sounds like the entire plug came out of the head. Is the plug broke? Where is it broke, just the porcelin?

  • mxkid23

Posted October 20, 2010 - 06:37 AM



everything that is off the plug is whats in the block.

  • tech24

Posted October 20, 2010 - 06:51 AM


i see, guess the previously metioned advice stands! Good luck!

  • mxkid23

Posted October 20, 2010 - 06:56 AM


yeah im going to have to try and get it with an easy out.
thanks though!

  • brentn

Posted October 20, 2010 - 09:08 AM


I've always tightened my plugs just 1/8th of a turn past the crushing of the washer.
So you thread her in hand tight, then use the wrench and you can feel the washer starting to crush and when it becomes much tighter to tighten, 1/8th turn.

Is this correct?

  • grayracer513

Posted October 20, 2010 - 09:17 AM


Industry standard spark plug torque in an aluminum head is 12-15 ft/lb

  • mxkid23

Posted October 21, 2010 - 06:29 AM


i pulled out the plug yesterday night just got a flat head screw driver and it came right out . i think i may have over tightened it some so now i know not to put it in so tight.
thanks guys for all the help!

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