I have a 98 formula deluxe 583. Last year I put a stud into the heat exchanger. I had it welded, and put everything back together. I have put 300 trouble free miles on the sled since. Today I was riding and after 55 miles I started running hot. The temp gauge started reading up towards the top of the white hash mark. I shut it off to cool, then started out again. This time went into the red and I lost power. shut her down quickly. Checked for leaks, non. Coolant level fine. Looked at the heat exchangers and looked like snow was caked on. Checked Friends 99 mxz''s heat exchangers and they were free of any snow or ice like normal. What could be wrong? blocked system, air lock, bad thermostat? Help! I don''t think I did any engine damage, since I shut it off quickly when it went into the red.