On a new engine? Whatever conventional oil you've got -NOT synthetic!-. Run it for the break in period. If you go out and ride for a couple hours, that's good. Right after that, change it, with synthetic if you like. If you're worried about dropping money on the high end oils, then it's better to have two $5 oil changes than one $10 oil change.
i have a x2 140 and i want to get a pipe for it....my friend has a stock 50 with a fmf 4.1 on it so i tried to put his on my bike and it didnt fit....does anyone know what pipe will fit these x2 140s?? I really want that 4.1