Explain this joke from "Chicago" ("Turn your motor off")

In the play Chicago, when Velma is describing her former duo vaudeville act to Roxie (“I Can’t Do It Alone”) she tells three jokes as part of the act, and I don’t get the last one. Please explain it to me?

[li]"… She’d say, ‘What’s your sister like?’ I’d say, ‘Men.’ Yuk, yuk yuk…"[/li][li]"… She’d say, ‘What state’s Chicago in?’ I’d say, ‘Ill.’ Ya get that one? …"[/li][li]"… She’d say, ‘Turn your motor off.’ (Wild break.)[/li][/ol] where “(Wild break.)” apparently means (Velma makes an engine noise.), if the CD is to be trusted.

Just for the record, 1. You think she means “What is your sister like?” and are expecting an answer like “She’s very funny.” But instead, it’s actually, “What does your sister like?” Irony, and all that.
2. You think she means “state” as in Kansas or Minnesota, so you expect the answer to be Illinois. Instead, it’s “state” as in “state of being,” so “Ill” means that Chicago is not in good shape these days.
But I still don’t get joke #3. The way it’s delivered, I’m pretty sure it’s supposed to be funny somehow, I just don’t know how!

IL (sounds like Ill) is also the abbreviation (why is that such a long word) for Illinois

No idea about #3 though

is #3 something other than her being contrary? “Turn your motor off”=calm down/kill the libido and her response “vrrrooomm!”=No!/woohoo sexual drive!

I dunno.

When a cat is making that strange internal noise they make, some people say the cat has it’s “motor running”. When someone is making sexually explicit advances towards someone else, they are said to have their “motor running”. I’m not sure if either one of these apply to the joke, but I think I’m getting close. IMHO.

I couldn’t sit through “Chicago” (couldn’t stand the music), but the only thing I could see was that in the act, Velma is supposed to be the dumb one (a la Laurel and Hardy), and when told to turn her motor off, she’s so dumb she revs it up. But, since that’s not really very funny, maybe not.

You’re right about that one. The joke is that the state is both “IL(linois)” and “ill (sick).”

As far as the motor thing, my guess is that it means something along the lines of ‘cool your jets’, and the joke is that the request was taken literally. In the score (I’ve done this show a number of times), Velma’s supposed to make motor noises, and the cue in the percussion section calls for “auto horn ad lib - quasi Harpo Marx”, and there’s a kind of crash at the end (the car turning off, perhaps).

Slight nitpick for clarification. IL is the Postal Service’s ZIP code abbreviation for Illinois. Ill. is the abbreviation for Illinois.

To nitpick the nitpick, Ill. used to be what we were told to put on envelopes, as well. That’s what we Illinoisians were taught as kids. Then they got all fancy sometime in the '80s and we had to learn to drop that second l and the period. And capitalize.

I don’t get the third joke though. Is it possible it was a visual thing that doesn’t come off well on CD?

Perhaps it is an obliquie reference to long timed stop lights in the Windy City.
(i.e. Turn you engine off and safe gas.)?