A month ago my ST1300 was serviced by my local dealer (who usually do it), and I noticed afterwards that the gear changes both up and down had become somewhat clunky. Oil used was their own "L1002-HP4-13205" bulk oil, which is what they have always used. Checked the oil level today and found it was slightly overfilled and level with the top of the window, so I drained a little out, so that it's between the lines in the window. Gear changes up and down are still a little clunky. Any ideas of a possible cause?