I found out the hard way that medicinal castor isn't good for engines many years ago by seizing a new ST G20/15 I was running in but the GX 40 needs castor oil in the premix but, after a lot of internet searching, I've found that unfortunately 100% pure castor oil just doesn't seem to be available in the UK, the nearest being Maxima 927 which seems to be largely castor with some additives. Shell castor M seems similarly to be castor based but not pure castor. Castrol R (which I remember from the '70's) doesn't seem to be made any more. Other than Klotz (which doesn't seem to be available in the UK) is there any other make of oil out there that might be available in the UK to suit this engine?
