This is a Standard SBT brand new naturally aspirated 1503 engine that fits Sea-Doo. SBT's engines for Sea-Doo include all new crankcases, cylinders, head and internal components. They will also include the valve cover. SBT tests all of the 4-stroke motors on our Dyno before leaving the SBT Factory Manufactured in the USA! Purchase of an Installation Kit is required with a standard engine.