The Racetoolz head saver kit is designed to repair damaged valve guide holes in Kawasaki KZ650 through GPZ1100 2 valve cylinder heads. Damage can occur when old guides are driven out with carbon on them, valves run into each other, breaking and moving the guide, cracking the guide boss which requires welding. Whatever the case, the head saver kit will ream a new oversize hole on center of the tappet bore. Then install one of the special guides that come in the kit, and it is fixed. Touch up the seat and it is back in service. The reamer opens the hole .025" which should be more than enough to clean up the most severely damaged guide hole. Quit scraping these heads because of valve guide hole damage. Every shop that works on KZ cylinder heads should have this kit.
Each kit includes one head-saver bushing, one reamer, set screw (to easily lift the bushing from the tappet bore) and two +.027 oversize bronze valve guides.