Hi All I've recently upgraded from a 1991 GPX 250 to a 1999 CBR600F which I bought through a dealer. The CBR had about 61,000 Kms on it when purchased and it's going to be due for an oil change soon. I was thinking of putting a synthetic oil in it but I'm not sure if this is consistent with what the previous owner did when he owned it. Does anyone know if there are ant pitfalls in putting a synthetic or semi-synthetic in a bike that has possibly run the last 61,ooo Kms on a mineral oil. I've heard somewhere this can potentially cause problems. Thanks for any ideas.