GoGreen knows how to tune up my generac generator, and we are grateful! But they don't stock the kit (filter etc) and always have to special order it, and it always takes more than 1 week to arrive, which has meant rescheduling the appointment. This year, despite my explaining this experience and earnest pleading to order the kit with plenty of time, the appointment was scheduled before the kit was ordered, and would have again occurred before it arrived. This took quite a few phone calls to sort out. I am hoping for smoother sailing next year.