Left my Westerberke with SMD for 3 weeks. Spent over 3000.00 dollars for a tune-up. Did not start generator when picked up. Found out latter after being charged for new NGK installed, there where my old black Champion plugs still in there. Emailed the owner twice as to why the old plugs where still installed after paying for new ones. No response. Makes me wander what else was left out and charged for. Make a mistake, just own up to it. Good Business sense.