First thing. Just bought a 07 GSXR 600 with 14k miles. Not sure what type of oil the previous owners(s) have been using but I do have a question. If i decide to go with a Full Synthetic, can i? even if full synthetic has never been ran through it? Also, if do go with full synthetic, do I have to stay with that, once i start putting it in? Lastly, I was wondering what everyone thought of putting Amsoil in?