Pull the counter shaft cover and check the sprocket for wear. It is a good indication of how much and hard it has been ridden. Check the a-arms for sand blasting or dents and look under at the skid pan . Do a compression test. Look at the oil and see how dirty it is. Check the grips are they stock and how worn are they. Same for the tires. One of these thing may mean nothing but put them all together and it can give you some indication of how hard it has been used. Good luck and I hope it is a great deal. you will be rolling with the big boys!!
dont forget the scratces on the cases where your foot would be when shifting breaking
