Originally Posted by
drac1
The blue oil (which is used in coolpower) is better for four strokes.
And the coolpower purple MV is preferred for YS four strokes.
This is good to know, but for how little I use I can't justify spending $60 on a gallon of oil. If I were to do that I'd be using Motul Micro or Aerosave/Aerosynth at $75/gallon. Castor works just fine in my four strokes; the mfg. specs castor oil or high quality synthetic blend. I know YS don't like gooey oil, but I don't own any YS engines.