i have an 03' preddy 500 that has started to smoke! it's blue smoke, but the motor dosen't use any oil? the motor still has tons of power but it does smoke quite a bit. could this be a valve problem like needing an adjustment or new valve seals? when it idles, it sounds like the timing is off a bit?? please help!

 

i also run gtx 20-50 oil in it, would that harm the motor?