Re: Again, Mini overheat troubles.

[Mike Rambour <mikey@b2systems.com>]

  did you check to make sure the t-stat opens ?  or even try running 
without it to see if that helps, I don't recommend running without 
one long term but if the B-stat does not open that will overheat you 
in a hurry.  Its super easy to check, throw it in a pot of water and 
bring up to a boil, it will open long before the water boils, even 
easier if you have a thermometer.

   After that, like the other poster said, time to start looking at 
cooling jacket corrosion or radiator as its already been said.