peter, I’m assuming you are using kart for recreational purposes. I run maxima 927 castor based oil on my kart at 24:1 ratio. that’s 6oz of oil per gallon of fuel. I use vp ms98 min or Sunoco 110 and never had a problem with wear on piston or cylinder. don’t know what carb your using or your main, pilot jet settings are? my cylinder is a 99.