I guess I better rethink my oil choice. Im a new TBA owner, a 2003 with 13000 miles. The bike was obviously very well kept. I just changed the oil for the first time and used castrol syntec blend 10w-40. This is not motorcycle specific oil but unless Im misinterpreting the owners manual I know it states semi-synthetic or synthetic but as long as it met certain other specs it doesnt have to be motorcycle specific oil. Correct me If Im wrong. I've not noticed a difference in shifting characteristics or clutch operation with before and after using this oil. Oh and by the way glad to be a new member of this forum, it rocks! Hello to all.