Join Date: Dec 2004
Location: Altofts zx-12r B4 UK
Your looking at the timing lug for the cam position sensor on the end of the Exhaust cam. They are in different positions depending on year and model. The ECU needs this to know when to fire the spark plugs at the right time when starting the bike.
For Tech Questions Bike Model letters and Country are more useful than saying the year, for UK owners anyway, as registration year is not always the year of manufacturer model.