I was emailed this picture the other day asking is this right as the engine had done only 270 miles.
Now I have been told that the cause of this is lack of oil in the petrol also I learned that modern synthethic oild burn quicker and therefore lets the petrol get hot and consiquently burns a hole in the piston.
So my dear friends 30-1 on synthetic oil is a no no and I have now found a supplier of classic oils in the classic cans. 20-1 mineral oil mix and SAE 40 in the gearbox, I am assured also that 10-40 tesco oil will eventually fail.
Oh and who told me this a guy that has been building two stroke race engines for Yamaha for 30 years.