race one’s motor, v. — Green’s Dictionary of Slang

race one’s motor v.

also rev one’s motor

1. (US) to become over-excited.

c.1943		‘Bill O. Lading’ You Chirped a Chinful!! n.p.: Quit Racing Your Motor: Calm down.
1947		B. Schulberg Harder They Fall (1971) 183: Quit racing your motor, Miniff.

2. to excite sexually.

1971		(con. 1930s) D. Wells Night People 71: She sure was a crazy dish. She raced my motor so you could cook an egg on my head.
2000		C. Cook Robbers (2001) 25: Talking wicked sweet. Revving his motor.