Kirk made 4-cylinder engines in "X" that were presented at the EAA in 1982. It combines a Bourke connecting-rod system and the latest 2-stroke technology.

-The were very compact and gave 25 hp at 5,000 rpm.

“Kirk”

-It was known as "X-4", and its total displacement is 413 cc only.

“Kirk”

-The magneto is an automotive Vertex and the carburetor is a sliding Posa.