This is an aftermarket engine top end rebuild kit that is compatible with the 1985-1987 Honda TRX 250 Fourtrax four-wheelers only (the utility model TRX 250 with racks on the front and back). This kit includes: (1)New Aftermarket Honed Cylinder. We make sure that each of our cylinders is honed before they leave our facility. Why is this important? Final honing of the cylinder creates a crosshatch pattern that gives the piston rings the correct textured surface for proper seating. This insures proper break-in for the rings allowing them to seat correctly which, in turn, provides a longer lasting top end rebuild. (2)A New Stock Size 74.00mm Standard Piston Kit. This includes a new piston, piston rings, wrist pin and two circlips. The stock size bore makes your rebuild hassle free with no carb jetting or modifications required. This ensures that when you receive this kit, everything is perfectly sized, machined and ready to bolt on. (3)A New Top End Engine Gasket Kit. This kit includes not only the cylinder base and head gaskets, it also includes the exhaust gasket, both valve stem seals, rocker cover gasket, o-rings, etc. (4)A New Oil Filter with Sealing O-Rings. We provide a new oil filter with the sealing O-rings which should always be replaced any time you rebuild your top end. You should always install a new oil filter to help insure longevity of your new top end rebuild kit. (5)A New Spark Plug that is specifically for these ATVs. (6)Instructions For Proper Break-In Procedures and Cylinder Preparation Sheet. Knowing the correct way to break in your newly honed cylinder is vital for ensuring the longevity of the cylinder. (7) Three Quarts of Honda GN4 10W-40 Motor Oil. (8) New Honda Air Filter. (9)Free G&H Discount ATV Supply and Hi-Caliber Powersports Parts decals.