I got the YZ back around 1990 for about $600. Was very original, if fact I bought it from the original owner. It had gone to another home before returning to the owner. I knew the original owner and also I knew the YZ had been MX' ed hard, hare-scrambled hard and logged hundreds of miles on northern Michigan trails and that was back in the 70's. When I got it I had no idea what the internal condition of the motor was. I did a quick once over on the bike and then took it and competed in AHRMA MX and Cross Country events for almost 10 years years including the ISDT Reunion Rides. That picture was from November 28th 2001 ISDTRR in Missouri. I NEVER pulled the top end; ever. The only real part to fail was the CDI which I replaced with a PVL ignition. The bike always hauled a$$ but after beating the crap out of it for years racing I was getting worried about the top end getting loose and breaking. Also, the YZ was a bit tricky in Cross Country (tight woods) so I parked it and got a Penton. It's sitting in my barn right now waiting for me to give it some TLC and a new lease on life. Some folks say these early YZ's were fragile. I would have to disagree.