Ok, earth checked 0 ohms on meter and cable looks in ok condition removed conection at stud near starter motor and cleaned cable ends and all ok.
Removed starter motor and noted top bolt thread gone in starter motor housing , possibly a bad earth here, so modified longer bolt and nut for a secure fitting. Tested now and still intermitant starting. Removed starter motor completely and set in vice on bench connected battery and tested perfectly every time.
Starter motor back in bike and still intermitant starting. Tested 12v from starter switch.