Plug Hole!
Posted: Thu Aug 15, 2013 6:45 am
Author: DavidZ1R
Took the head and block off my kz550 project, found that pot no. 3 has had some sort of thread repair to the plug hole, some bits have fell inside the cylinder, the engine been used, top of the piston pitted with hot metal, can change the piston, but can I have the thread to the plug hole repaired to last? does the helicoil system work on plugs? or is it a new head?
Posted: Thu Aug 15, 2013 7:04 am
Author: Charlie
It sounds as though someone repaired it in situ. rather than removing the head to do it. That is what can happen if you repair that way.
Unless the thread is crumbling, it should be OK to leave it in place as the debris will likely be cyl head debris where it was tapped oversize. Helicoil repairs are fine for spark plug repairs, the best repair though is to use a timesert. If you want to do belt and braces, get it to a specialist who can take out the old one and fit a new timesert type.