KF Overheat and emergency landing

I have a Kitfox III with a grayhead 582. I noticed on some recent flights that my thermostat was runnig a little warmer than normal (+180) on takeoff and settling back to 140-150. After flying and landing I notcied my radiator overflow bottle was always blowing off additonal antifreeze. I was concerned about this after seeing it a few times as to wondering where this addtional antifreeze would be coming from and why the sudden blow-off.

On a flight this evening I was again running warmer on the runway. I took off but at about 300 feet antifreeze was spraying into the cabin on the co-pilot side. I did an emergency landing and upon examination found that the overflow bottle now had a small crack in it. This might have happended from the last flight on the ground when I sqeezed the bottle to get some of the "blow-off" out of the bottle.

Now I am trying to figure out the reason for the overheating. I am not sure if I even have a themostat? Any ideas what it could be? Earlier ths summer I lowered my radiatior from suggestions on the Kitfox forum to put some spacers on the radiator to lower it from under the bottom of the plane.

I would appreicate any insight via email at kszaronos@aipc.com or call my cell at 317-506-2854. Thanks ... Keith