KC Mayor -- TAUNTS L.A. MAYOR ... Don't Bet On the Angels!

Everybody LOVES some good old fashioned smack talk ... even politicians ... just ask the Mayor of Kansas City -- who's rippin' into the Mayor of Los Angeles over the MLB playoffs.

Of course, the Royals are taking on the Los Angeles Angels of Anaheim -- and K.C. Mayor Sly James is stickin' it to L.A. Mayor Eric Garcetti.

We spoke with Mayor James before the Royals beat the Angels last night -- here's how the conversation went ...

Mayor James: "I'll be reaching out to the Mayor of Los Angeles and making a bet with him."

TMZ Sports: Who will you bet on Mr. Mayor?
Mayor James: "I'm always gonna bet on Kansas City ... and I'm gonna encourage him to do the same if he actually wants to win the bet."

TMZ Sports: What will you bet?
Mayor James: "We'll bet some BBQ versus whatever he wants to put up."

TMZ Sports: Any final thoughts?
Mayor James: "If he wants to be on the winning side of the bet, he ought to bet on the Royals. Save himself some trouble and heartache."