The engine originally had a head gasket. As a repair part, the head gasket is included in gasket set PN132.

However, I do not see the lack of a head gasket causing you any problem at this time.

I've found other four strokes with the head gasket having been removed. I ran one for a full flying season only to discover that someone prior had removed the head gasket. The engine ran good.

Enjoy,

Jim