If you thought the Norton's were junk, I had a 73 Yamaha TX750. The engine was junk. I heard it brought Yamaha to the brink of bankruptcy (rumour). Good looking bike, with a nice sounding exhaust and reasonable power but the balancer shaft, which was a new feature that year, whipped the engine oil up at higher revs aerating/foaming the oil, causing a loss of oil pressure and ...... My engine was rebuilt at 4000 miles under warranty, then I got rid of it. It was only made for 2 years. They even increased the sump depth to try and solve the problem.