Has anyone had problems with the 600? I bought a used one about 3 months ago and broke a connecting rod a few days ago. It wasted the block, crank etc. I was thinking of getting a short block or something but I'm not too sure of the reliability of the motor. I had only 1000 miles on it. It wasn"t overheated either. can I get a fan cooled to fit in there? or maybe the 500 motor? The rest of the sled looks brand new? what do you think? Im up here in Nome Thanks