Relax Hoosier, you should have absolutely no engine issues whatsoever. I've seen many 900's in Canada with 18, 20 plus K miles. My ace 900 Renegade is my choice of ride for our big, long mile Canadian trips. After taking the 900 to Canada for the first time, it was a no-brainer! Any of the ace 900's for that matter would be as they all get outstanding mpg's. That is really nice north of the border! Both of our Canadian trip sleds can run at least 220 miles on fuel. We bought the sled for my wife, and I was seriously questioning the purchase.
However once I got to ride it, I fell in love with the all but nonexistent, very low noise level. Makes for a very peaceful, and enjoyable ride, no matter how you're riding, hard, or fast cruising, or whatever. I did some clutch work with Goodwin, Dalton. and CVTech. Replaced the primary with a PB-80, and brought the RPM"s up to 78, 7900. I haven't been able to ride now for several years due to health issues, and I can't wait to get back to riding. I never get tired riding that 4-stroke ace 900! It's by far not the fastest, or a lake rocket. However it's very, very quick out of gate, and super in the tight twisties.