JASO MA/MA2 is a good start. If the oil is entirely compliant with that whole set of standards, then it should be a really good engine oil. The problem is that nothing in the standard says anything about durability in shear conditions, so it tells half the story. The transmission is what hammers down oils that aren't made for the purpose into something much thinner. Typically in a a YZF, the only thing wrong with an oil that fails in this way is that it's viscosity has dropped below the labeled grade. Everything else about the oil is OK. What I'm saying is that oils that are blended with the tougher, more expensive viscosity improver additives intended for multigrade gear box oils are a far better choice because they stay at their rated grade. Unfortunately, shear toughness isn't a component of any engine oil standard set by either API or JASO. This leaves you to do your own research and find an oil that you know holds up under such use. You can use published lab tests, published used oil analyses from other members, or run a test on your own used oil (look up Blackstone Labs). I first became aware of this particular shortcoming in engine oils about 15 years ago. At that time, I knew of only 3 oils on the market that were actually blended with gear oil additives. Since then, mostly within the last 5 years, the situation has improved to the point where about 60% of motorcycle specific blends and a handful of premium automotive oils are made that way. Still not everyone. I use either Amsoil MCF or Mobil1 Racing 4T, and change it every third ride day most of the time. That can be as high as 10 hours, but normally less.