RE: 4 stroke from 2 stroke fuel
I run Coolpower 15% in everythign whether it is 2-stroke, 4-stroke, YS, OS or whatever and have had zero problems.
Iliek the 15% in 4-strokes but I have ran them on 10%. There is a little bit of power loss and you have to be a little more careful about the idle mixture but most will run on it.