The K60 has a very stiff carcass and they require a much lower pressure. On dirt try 15psi front, 20psi rear. Sorry I don't know the metric equivalent.
2002 black Tiger955i, 72000 miles and counting.
2012 black Tiger800XC, The other British Land Rover. 40000 miles and counting.
2013 black Tiger800XC, The other British Land Rover. 500 miles and counting.