I finally got to a technical person at Kawasaki to ask about there oils. These were the questions I asked:
Why does Kawasaki do not give there oil the latest API SN rating?
Because of the lower Zinc and Phosphorous level requirement in those rated oils. They use flat tappets in there engines.
Does Kawasaki have any issues or concerns with lower zinc requirements in the API SM and SN ratings? Basically answered above.
If so, what is the minimum requirements for zinc?
1000 ppm
My conclusion: So any oil at there viscosity requirements and at or over there minimum zinc and phosphorous levels would be good. By saying that an oil is to meet API SL is not a good thing on there part, because your later rated oils are backwards compatible, so in a sense they are saying you can use the latest rated oils, if they know it or not.
Why does Kawasaki do not give there oil the latest API SN rating?
Because of the lower Zinc and Phosphorous level requirement in those rated oils. They use flat tappets in there engines.
Does Kawasaki have any issues or concerns with lower zinc requirements in the API SM and SN ratings? Basically answered above.
If so, what is the minimum requirements for zinc?
1000 ppm
My conclusion: So any oil at there viscosity requirements and at or over there minimum zinc and phosphorous levels would be good. By saying that an oil is to meet API SL is not a good thing on there part, because your later rated oils are backwards compatible, so in a sense they are saying you can use the latest rated oils, if they know it or not.