I really don't think you'd need one. Have you ever seen the demos where they run over one of those decks with a truck? They are amazingly strong. I've had 2 21" prolines with the cast decks, employees managed to crack both of them, I've had the standard cheapo stamped steel decks, those rust, bend and crack, my Xelite deck is 5 yrs old now, and it doesn't have a single nick in it. We only use the 21s where we can't get a bigger mower, so my 21s are going up and down stairs, and over rock walls and the like all the time. All I have EVER done on the Honda is change the oil, air filter and sharpen blades. Heck, I am still on the original spark plug, just have cleaned it a few times. The only problem you should have is with the air filter. All my Honda motors are very sensitive to air flow. Keep the air filter clean, and you should be fine.