2009 Arctic Cat F8 Overheating

Hi Everyone.  I recently bought an AC 2009 F8 Sno Pro. I ride on groomed trails in New England in what we call 'springlike conditions' about ninety percent of the time.  The other ten percent is rare, but we occasionally get to ride on fresh powder from the night before.  Since my purchase of the F8, I have riden a grand total of 25 miles.  The first time out, with fair/good trail conditions, the Speedo/Tacho began flashing the TEMP warning indicator at about 2.5 miles into the ride.  I nursed it for another 4 miles, riding the shoulders when possible, and stopping about every half mile to cool down.  After that ride, I installed a new heat sensor and a set of scratchers.  For my second ride, in better trail conditions, the TEMP warning light stay off until the 3.5 mile mark.  At that juncture, I jumped off the sled and engaged the scratchers.  It only took about a half mile to cool off, and stay cool.  So, what's going on?  The track is studded, and both rides were in conditions that should have kept the engine cool.  My main concern is that this sled is not designed for my type of trail riding.  Especially when our trails are marginal for most of the season.  Is the heat enchanger too high?  Is it in the wrong place?  Is the circulation too slow?  What can I do other than scratchers?

Tom