I had one bike that stripped the lock nut on the ball joint (they put the wrong size nut on) and break the cotter pin. The ball joint came apart while my son was riding and each front tire went a different direction. Luckily he was going slow and it stopped without him getting hurt. This was with less than an hour on it. The exhaust fell off the next trip as well as the air filter assembly and I did not have extra hardware with me so our day of riding was over in 20 minutes. Our third and final trip was in Glamis. I got one day out of it before the bolt that holds the back of the engine to the frame disappeared which sent the chain flying, ripping the shroud off and bending the sprocket. The seal behind the sprocket leaked oil everywhere.
I was getting pretty good at tightening every nut and bolt after every ride on ALL of them; then my daughters 90 lost power while riding. Blown fuse- replace fuse and blows again. I checked over the whole harness to be sure it was not rubbed through somewhere and found nothing. The dealer has had it for a week and still can't figure out the problem.
If you buy one of these, carry spare parts and lot's of spare nuts and bolts. Be prepared to work on the same amount of time they ride it. Even then, they might not make it through a weekend. I have no one to blame other than myself so I'm not bitter about it. I just don't want to see anyone else go through this. Between my brother and I, we bought 6 of these things. All 6 are at the dealer right now and have been for a week.