EXCEPT for those times the automatically 'tuned' valves don't. Or what I run into now is the 8KW generator needs to have the valve lash adjusted. The young guys don't even know what that means in the owner's manual. If you're one of those young guys, don't feel bad. Most of my generation (boomer) never wrenched either. I started at 6 (years old). You get really strange looks if the conversation ever goes that direction in a board room and you pipe up with specs for valve lash, or dwell, or point gap. It's almost like you are from Mars. What they don't realize is I'm looking at them like they are from Uranus. (most of them are an anus BTW)