4 stroke from 2 stroke fuel
I've been running PowerMaster for several years now in my 2 strokes. I like it fine. The past year I have aquired my first 4 stroke engines and love them. But the LHS sells the YS 20/20 blend and it is pricey stuff. Can I just by the 2 stroke stuff, 10% nitro, 18% oil and then add some caster to bring the oil content up to the recommended 20%? And if so, where do I buy caster oil?