Does anyone here know the full function of the rear head temp sensor on the XB motor? Does it affect the cold start circuit or is it used for over-temp condition, or both. I'm building an LSR bike with an XB9 motor and I have dual plugged the heads. The second plug on the rear cylinder goes where the temp sensor is located. I would like to know if I can run without it or if I need to find another spot to locate it.

Well, it looks like I have answered my own question with a little more research. The Head temp sensor works with the ECU in the full operating range. The temp sensor is just a 3/8-16 plug, so it will be easy to find another spot in the head to drill and tap a new mounting location.