Airsal 77cc Racing cylinder kit, complete with all necessary parts, such as gasket set, piston, piston rings, etc. incl. cylinder head. The 77cc M-Racing has the same timing as the 77cc Racing and has a 2-Piece outlet. The difference is the MAHLE piston (2 rings). Aluminium with hard-chromed bore. AM engines have the benefit that no crankcase work needs to be done.