spark plug popped out of block! help!

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!

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.

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

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.

I install all my plugs never has this happened

You mean it's never happened before :excuseme:


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

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

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

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?

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

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

thanks though!

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?

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

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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