It seems that no one outside of Kawasaki knows. Here is what we do know: there were some instances of the activation switch sticking 'ON' (down) on C-14s made in '08 and '09 and perhaps later. There was a change of the part number on the ignition switch assembly between Gen.1 and Gen.2 bikes (2009 ends Gen. 1, 2010 starts Gen. 2) but it is not known what was changed. The sticking switch problem seems to have occurred less on later years but has turned up on Gen. 2 bikes all the way to 2011 if I remember correctly. I <assume> Kawasaki is using the stiffer spring on the current ignition assemblies but again, no information is available that I have seen to indicate exactly what was changed or when.
When a C-14 does have the sticking switch problem, Kawasaki supplies the dealer with a stronger spring and pays for the labor to R&R the switch assembly and replace that spring. The spring does not have a part number nor is it available as a separate part to customers / owners of C-14s.
Sorry but that is the best information I have and it is not very conclusive.
Brian
So if I am reading this thread correctly, Kawa replaced a spring on later model bikes? What year did they make the switch, and has there been any issues on bikes with the beefier spring? Just curious.