I really can't see any possible problem with what you plan to do. As Grant pointed out, leaving it in Canada or America for up to one year is a non-event, that's fine with everyone (US or Canadian government). It's also important to note that neither government has any interest in controlling the motorcycle when it is shipped out of the country - meaning, there is no customs paperwork to do when you leave.
Plus, if you exit USA into Canada or Mexico, then when you return, you have "set the clock back" to zero, so far as your stay in the country is concerned.
I do know that the Canadians and Americans have a computerized system that records the licence plate of every vehicle crossing the Canada - US border in either direction - they do this for tax (VAT) purposes, not for vehicle control - so if you enter one country, your vehicle plate number is noted and the one year timer starts from that date. Leave the country and re-enter again and the timer starts again from zero.