To answer a question i have been asked many many times over the years. “Do i use a fully synthetic oil in my bike”. Ducati for example have have always recomended the use of Fully synthetic in their bikes whilst the Jap manufacturers suggest a Semi synthetic. Why? It is normally due to tollerances, at least for a while anyway. A semi synthetic oil will allow the engine to “run in” and if you change it regularly is perfect for most bikes. Triumph for example suggest a Semi until the bike reaches 12000 miles and then start using a fully synthetic. Unless you are racing it i would always suggest using a Semi in Jap bikes unless it is really big on miles. One thing a fully will do is stick to the metal parts even if you have not used the bike for some time, great in the winter of course, better for the first start up of the season. Oil manufactuers always stress that most engine wear happens at start up when the engine is cold.