Motor Maniacs(1946)

Edgar learns that an old, rich, oil-man flame (Tom Kennedy) of his mother-in-law (Dot Farley) is coming to claim his bride. Meanwhile, his brother-in-law (Jack Rice) has bought an interest in an outboard motor that is supposed to run all day on a cupful of gas. The suitor says he will finance it if the test is a success. Edgar is accidently pulled into the lake with the motor and it works well, but the "rich" beau says he will finance it as soon as he can find somebody to finance the drilling of his first oil well.