If you want to buying second hand bike first of all check the bike documents clearly if it is clear then go for checking the performance of the bike first check the engine performance of this bike and next one is seating comfort first of all ride once and check the comfort and next important thing is road grip of the bike if it is good road grip performance then off of the bike is good and next is break system check perfectly and one of the regular problems in second hand bikes is oil leakage if it is ok then buy the bike