sounds like the injector went out, and did you rejet your carb for the cold weather?
also, is english your first language?
and don't take the engine to a shop, do it yourself. the only time i took any engine of mine to the shop it was do replace the gears, i will not split a case. but i have the engine, taking out of the frame and just brought the bottom end to the shop, and this was for my old 660r.