sixteen components are shown in this Cn250 Helix 1990 (l) England Mph Gasket Kit B exploded diagram.
Some items from this specific schematic: Gasket,r Crank Ca (mca), O-ring 47x1.9, O-ring,13.8x2.5, O-ring 46.4x1.9.
The Gasket Kit B is made up of components including this Gasket Kit B which is the most expensive.