What was found
AT FL280, CREW CALLED INTO OPERATIONS CONTROL CENTER TO ADVISE OF AN UNKNOWN ODOR IN THE AIRCRAFT, AND SLIGHT VISIBLE SMOKE. THE CREW PULLED BACK ON THE THROTTLES AND THE SMOKE DISAPPATED. THEY THEN POWERED BACK UP AND THE SMOKE WENT AWAY. THE ODOR REMAINED AND AT THAT POINT, THE SIC CONTACED ATC TO DELCARE AN EMERGENCY FOR SMOKE IN THE COCKPIT. THEY CHANGED THEIR FLIGHT DESTINATION TO ELM FROM CYYZ IN THE PROCESS. THE PIC, NOT WANTING TO DOWN-GRADE THE EMERGENCY STATUS, GOT ON THE RADIOS AND ADVISED THAT ALL IS WELL AND THAT THE ROLLING OF EMERGENCY VEHICLES WAS NOT NECESSARY. FOUND BREATHER TUBE KINKED.