Hi,
I am essentially a happy owner of a 2007 Crossfire 5. It now has 1175 miles on it. There have been NO problems with breakage of any kind. The factory claimed 84 horsepower. Power is about what I had expected from the 500 non-APV engine. It is very snappy, easily keeping up with most 600s in acceleration up to about 50. Top speed varies with conditions, like any sled. It is just that adverse conditions have less affect on sleds with a surplus of power....which this one don't have. The fastest I have saw on the speedometer was 92 under perfect conditions. The road was icey with about an inch of fluffy snow and the temperature was around 10 degrees. Two weekends ago, on a rail grade which had received about 6 to 8 inches of fresh lake-effect snow since grooming, I could only manage 77 with a similar temperature. Generally, I will say the 85 +/- top speed is very close. Throttle response and pull from any higher speed is where the small engine ceases to impress. As far as power to ride in deeper snow or climb hills, there is plenty. You can spin the track as much as you want.
There have been a pair of minor annoyances. The engine still has the plugs that were put in it after the first season, which I only rode the sled 450 miles. That first season, though, the oil was really rich. I checked the average over a few tanks of fuel, and it was averaging 25:1 gas to oil. After adjusting the oil rod so the mixture averages 50:1, it is less inclined to load up and smoke is reduced noticeably. A recent plug check tells me the sled is still running a tad rich on oil and gas. Fuel mileage runs between 12 and 14, right where my ZR 600 EFI runs. On the last riding weekend, in that fresh snow hitting it pretty hard, I went 110 miles on just under 10 gallons of gas. By the time we gassed up, there was well over a foot of fresh snow on the trails. I had hoped the 500 would be better gas. Unfortuanately, i still can't kick the off the line power problem I have has since new. It is a little better since the oil adjustment, but not gone. If I hit it from a standing start after riding at a pretty good clip, there is a barely noticeable hesitation. If the sled is putt putted, or worse yet, idled for any length of time, there is a full fledged bog. It looks on the forums like EFI Cats of all sizes are now suffering from a similar condition. Funny thing is, my 1998 ZR's EFI was spot on and never hasitated at any speed due to calibration, mapping, or whatever is causing this.
-Les