bluebell

hi everyone just bought a yzf and she's wonderful however I've been told that the cam chain might need tightening how can I recognise this for myself and are there any other technical problems that might be associated usually to my bike, would you recommend I have her serviced I don't want to pay for something I don't need. She's second hand mint condition 26,000, P reg, full years MOT, blue flame exhaust and I paid £1800 quid is this about right. Not knowing anything about the model itself as I was going to buy a thundercat but fell in love with this help would be reallllllly appreciated. bluebell