Spark Plug Hole Thread Repair

Yes. 

wrote:

Yes. 

Understood, Thank you.

Still have to be careful not to cut off angle but safer than without it. 
Steve

The M14 (small) portion of the tap was able to grab the remnant thread base on the hole wall, even after 90% of it was pulled out like a spring coil, which began this whole adventure.



Should anti-sieze compound be applied to the threads, considering more of the steel insert core material becomes exposed as the plugs are removed and replaced? 
 

wrote:

Should anti-sieze compound be applied to the threads, considering more of the steel insert core material becomes exposed as the plugs are removed and replaced? 






 

No, the last two un-cut threads will help to turn in the in-sert and will be pressed/formed into the head aluminum after the insert is fully seated and do a permanent lock. Didn´t you watch the YT video? You can use anti sieze but it´s not necessary.

 
 
 

Did you use the expanding tool after you were done. It's supposed to expand the bottom few threads to lock the insert in place. You screw it into the insert past the resistance of the last few unfinished threads. That makes the bottom expand locking it in place. 

Hey guy's, I'm wondering if I should use anti-sieze on the SPARK PLUG threads, not the inserts...



Sorry I didn't ask the question more clearly.   But hey, my mind is out riding today.

wrote:

Hey guy's, I'm wondering if I should use anti-sieze on the SPARK PLUG threads, not the inserts...

Sorry I didn't ask the question more clearly.   But hey, my mind is out riding today.

I knew what you meant!  
And my vote is YES.  Can't hurt.

Yes, always anti-seize on spark plug threads unless you enjoy gauling the threads, which I bet you don’t.
BTW, that’s a beautiful repair. Better than stock.

I've owned my 1977 KZ650-C1 since it was new (Feb. 1977) and have never used anything on the spark plug threads.  I have never experienced a problem.  The bike now has more than 61,000 miles on it.  Ed

It's just me, but I'm a firm believer of " Having it and not needing it than needing it and not having it." Firearms, spare parts and anti-seize included.

Also, just found this. I'm not Z1/Z2 specialist, so not sure if this is the right head, and how hard to fix it.

page.auctions.yahoo.co.jp/jp/auction/c1053000580