Can you use motor flush on lawn mower?

Not recommended...purchase some high mileage 10w30 oil and will clean it slowly and safely. Using a flush on a cruddy engine may dislodge large pieces of debris and damage the engine. Alternately, use one oz of marvel mystery oil in the crankcase and it will dissolve sludge and varnish gently and the same in the gas. keep an eye on the oil as it may turn black rapidly if your engine is heavily sludged and require a change. the mmo in the gas will dissolve the carbon buildup on the combustion chamber. It is a fantastic product that has been around for 100 yrs without a single black mark. It also works extremely well as a gas stabilizer. I add 4 oz to 5 gallons when I purchase gas. Never have had a fuel related issue since.