I bought my CForce 500 HO used about a year ago and the previous owner had bypassed the fan switch and put a rocker switch on the handle bars.  After a bunch of searching I found NAPA PN 143-5040 is a direct replacement for the radiator mounted temp fan switch.  Cost is about $20 and the connector is the same as the old switch.  I couldn't find the specs for this switch but it seems to switch the fan on a 5 bars on the temp gage and off at 4 bars so I feel pretty comfortable about its operation.  The switch is made in Japan and also has PN BS-506A on the box.  Hope this helps someone.

[2015 Z Force 800 53/Trail EPS]

Seems a little high. Most OEs maintain it in the 3-4 bar range. 5 bars is considered borderline overheating. Of course that gauge is aslave to the temp sending unit which may be off  some.

[2015 Z Force 800 53/Trail EPS]

I find that switch has an ON temp of 98C which is 208.4F. That would be a normal ON temp for these machines. That means it will cool down to about 10 degrees before shutting off. Your temp sending unit or the gauge is off for some reason. Good to know about the switch though. That one will probably fit most CFMs.