lemon lover is not correct. Motor bikes can be registered legally in Kunming, if your residence is outside 2nd ring road.
Also new bikes, if the bike has CCC, fulfills China Emmision Standards (C3) and all duties/taxes are paid there is no limitation...Harley, BMW, Ducati, Honda and all local stuff like Benelli, Jialing, CF, Shineray, Galaxy...
CaiYuanBei Lu is the place to check, just west of the new subway station. Lots of dealers, different local brands. imported brands not Kunming yet...Shanghai 6 beijing are ports of call
Good resource with maps and coordinates on "where to" in Kunming is www.mychinamoto.com