Well.. received the new cylinder head.. and fitted it... The engine is back to form again.. It's not the easiest to start, though, probably doe to the position of the carb. While with my 55cc one, rocking the prop will pump the fuel into the carb and then into the cylinder, with the 111, it reaches the carb ok, but then spills out. You need to turn over the prop a good few times (approx 20) before it reaches the chamber and then will start...and then if you leave it for a more than 10 mins between flights, the fuel seems to drain back out of the engine again and it takes ages to start..
However, the plane flies like a dream. Its a lot easier to land than the 55cc one. It just drifts down ... magic !!!!