I have a low mileage (gasp! I know) 2010 ST1300, with about 7000miles. I was preparing to do an oil change and found a nice coat of oil and grime on the bottom of the oil pan. Decided to bring her to the shop to have it checked out. Thank goodness for extended warranties. Shop manager called me, said the balance shaft o-rings were the cause, and that it calls for 10 to 11 hours of labor, possibly having to pull the entire engine out to do the work. There is a slight chance of doing the o-ring change without pulling the engine out. I gave them the green light since Mother Honda is taking care of the bill. (I know I actually pay for it). This is the 2nd major surgery for this bike. The first was the dreaded high idle when I first got it, in which Honda replaced ALL of the cooling system to correct it. THANK GOODNESS FOR EXTENDED WARRANTIES!