Gear box output shaft Z190 15mm or 16mm needle roller type
If you are replacing this shaft due to the idle part snapping off you need to make sure the decompressor is working and you are using the just over dwell kick starting method or the shaft will snap again straight away.
Worth changing all 3 sears if you have had a shaft break as the slightest tooth damage can cause the shaft to snap again.
we don't recommend using the kick start if you have the 15mm option.