LOOK AT YOUR AIR FILTER AND MAKE SURE IT LOOKS LIKE THIS ONE IN THE PICTURES. PLEASE BE SURE THIS KIT IS CORRECT FOR YOUR MOWER BEFORE PURCHASING. For sale is a NEW Tune up Kit for the Bad Boy ZT Mowers with the 26 and 27 hp Briggs and Stratton OHV Engine. The kit comes with an air filter and pre filter, fuel filter, oil filter (MADE IN USA), and two Champion RC12YC spark plugs.