NGK Iridium spark plug problem

[J3NNINGS_024]

hey people, today i took out my spark plug to have a look at it (jetting). anyways, when i put it back in i did it up finger tight then nipped it up with the ring spanner like i always do. when i went to nip it up the plug never got tight and i thought "oh sh*t i've stripped the thread!". but when i tried to take the plug back out it just slid out, leaving the threaded part of the spark plug in the head. i managed to get the threaded part out with a screwdriver but the thread in the head looks all chewed up.

heres 2 pics of the spark plug. i counldnt get any of the head as the cam wouldnt focus in the dim light. any suggestions on what i can do would be great.

cheers , brad

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[motophreak]

the exact same thing happened to me... http://www.miniriders.com.au/ask-tech-masters/27628-spark-plug-thread-broke-off-head.html
i got mine out but my thread was also chewed up so i took it to my local bike shop and they re-thread it.

 

[sean01]

yeah happens a bit, specially with china plugs but iv also seen ngk's do it..

do as said above (local bike shop and get it heli-coiled)

or go buy a heli-coil kit and do it yourself..

if doing it yourself make sure the engine is on TDC or youll bend a valve with the tap.. and yes this can be done with head still on... done it heaps of times.. oh and make sure the heli-coil isnt longer and it needs to be..
afterwards just turn the engine till the exhaust valve is open and blow it out thru the spark hole..

 

[J3NNINGS_024]

1st suggestion would be.... buy a new plug. lol

Question 1: When jetting, did it run lean and did that plug get overly hot??
Question 2: How tight is nip??
Question 3: Do you know how tight plugs are meant to be done up??

lol, answer 1: i dont think its ever been lean. when i first jetted it i put the richest jets i had and worked from there
answer 2: a nip is just a bit more thighter than what it is
answer 3: yes, i have put in more spark plugs than you can poke a stick at

the exact same thing happened to me... http://www.miniriders.com.au/ask-tech-masters/27628-spark-plug-thread-broke-off-head.html
i got mine out but my thread was also chewed up so i took it to my local bike shop and they re-thread it.

ahh so im not the only one to have this problem

 

[J3NNINGS_024]

yeah happens a bit, specially with china plugs but iv also seen ngk's do it..

do as said above (local bike shop and get it heli-coiled)

or go buy a heli-coil kit and do it yourself..

if doing it yourself make sure the engine is on TDC or youll bend a valve with the tap.. and yes this can be done with head still on... done it heaps of times.. oh and make sure the heli-coil isnt longer and it needs to be..
afterwards just turn the engine till the exhaust valve is open and blow it out thru the spark hole..

thanks sean, i'll look into doing it myself but i'll use this as an excuse to take the head of and do some porting lol