In this schematic the "Screw, Pan Head (e56)" is used most often.
Parts such as the Repair Kit: Valve, Needle, Pin,dowel (646), Lower Unit Gasket Kit (nas), Gasket, Exhaust (nas) are included in the 2mhq 1992 Repair Kit parts fiche.
Of all the components used in this assembly the Water Pump Repair Kit is the most expensive.
