Spark Plug Holes

Hey everyone,
I am having problems with the spark plug threads on my stock '78 KZ 1000. It seems that the actual threads in the cast head are breaking off and coming out when I stick a little duct tape down the hole and swirl it around. I have pulled out chunks this way, and it is happening on 3 out of the four holes with the number 2 cyl being the absoulute worst. I know about the Helicoil option, but rather than spend money on having a shop Helicoil three holes, should I just invest in another head? Do I have any other options? Thanks for any advice.

Most heads you pick up on eBay or elsewhere may have the same issue. I suggest that if you have a couple of plug thread holes that need fixed, remove the head and fix them. Put in a solid insert; not a helicoil and use one that is held in place with anaerobic thread locker. I use NAPA insert for this reason. Get the longest ones they have and cut them to length as they will come either short or too long. Just put inserts in each hole while the head is off. Re-install the head with a new head gasket.

put some antiseize on plugs before you screw them in;)

WSU_rider wrote:

Hey everyone,
I am having problems with the spark plug threads on my stock '78 KZ 1000. It seems that the actual threads in the cast head are breaking off and coming out when I stick a little duct tape down the hole and swirl it around. I have pulled out chunks this way, and it is happening on 3 out of the four holes with the number 2 cyl being the absoulute worst. I know about the Helicoil option, but rather than spend money on having a shop Helicoil three holes, should I just invest in another head? Do I have any other options? Thanks for any advice.

This might be what you're looking for:
www.timesert.com

later...

Are these holes not tap-able, or what?

listen to the all wise wireman!
anti-seize (a good cooper colored one) is your best friend with spark plugs.
samwell is on the money with a timesert idea.
trust me, i know.
every damm bike i ever bought had a insert put in that came out with a plug change.

Post edited by: kawsakiman, at: 2007/05/13 23:51