The Mini Powercore 4 is the best bang-for-your-buck performance bolt-on for your mini. Offered as a standard Mini Powercore 4, Closed Course Big Bore System or as a Spark Arrestor Version, the Mini Powercore 4 features a Hi-Flo stainless steel core and formed end caps, an aircraft-grade aluminum canister and a durable stainless steel header. It's pounds lighter than stock and you will swear the motor has been bored and stroked with the first twist of the throttle. Hi-Flo core and end cap. Pounds lighter than stock. No spark arrestor. Note: For closed course competition use only. Not intended for street use. Detailed Specifications: Type: System. Header construction: Stainless steel. Header type: Hi-Flo. Weight: 2.7 pounds.