How do ppl not know when the sled will be in? My dealer flat told me.... As for motor problems I think you're safe... Both doo and Polaris do extensive motor testing these days(unlike past) and they are required to meet a certain amount of miles before the motor can be put in models for public sale. Polaris used the axys motor on race sleds a whole year before release, doo had numerous demos out and certain pros testing the better half of the year...both my axys didn't let me down once nor did any others I seen... As for the doo 850 the one I spent time on had 1500 miles on it and I couldn't tell it from new. They did put over 3000 on them I believe.
