For regular fuel system maintenance of all gasoline engines, we recommend Berryman B-12 Fuel Injector Cleaner (part #0116). The recommended treatment ratio is 1 oz. per gallon of fuel. For your Harley and pickup truck we recommend a treatment every 3rd fillup, and the same could apply for your lawn equipment.   If you are looking for a deeper cleaning treatment, try Berryman B-12 Total Fuel System Cleanup (part #2616). This is our best detergent-based fuel additive and will “deep clean” injectors, carburetors, intake valves (in non-GDI engines), and combustion chambers.  You would use this products in your vehicles about every 5-10,000 miles at 1 oz. per gallon, and continue to use 0116 in between for regular maintenance.