After 20 hrs you need to do a valve inspection. You can figure out how to do it in the how-to forum. If you are not comfortable doing it, I would suggest taking it to the dealer. I made my dealer give me 1st service for half price. It takes about 2 shop hours to complete. Depending on shop rate mine was supposed to be $150ish but I paid $80. But I worked a special deal because I bought 2 at the same time.