I just purchased an HP 50" with the 27hp Kohler. I just put my first 5 hours on it. The dealer said I should change the oil and filter after the first 5 hours. He noted I should also nut and bolt the machine. That all makes sense to me. Anything else I should do? Also, what kind of oil should I run and how much oil does this engine require? Thanks for putting up with a newbie Mike.