Gustav lives in Värnamo. He constructs a new boat engine, but needs time to complete it. The work has been financed by factory director "Hatt-Johan" Johansson who would like to sell the invention. Gustav's father returns from the United States and everyone thinks he's become a millionaire.

Den åldrige August Söderlund äger en mekanisk verkstad i Värnamo. Affärerna går dåligt, men hoppet står till sonsonens revolutionerande utombordsmotor. Landsbygdsromantik och buskishumor med Sigurd Wallén och Sickan Carlsson i rollern – och i filmen dyker också Johnny Bode upp som gårdsmusikant.