Bruce Willis has paired up with a fast-talking Black comedian in a violent, funny and gloriously R-rated throwback to ’80s buddy-cop action films.

That movie was 1991’s The Last Boy Scout with Damon Wayans. Cop Out, on the other hand, is a shockingly inept endurance test pairing Willis with Tracy Morgan in the first film Kevin Smith has directed that he didn’t also write.

When 12-year-olds make a cop-movie parody with garish camerawork and interrogation-room dialogue cribbed from Heat, Training Day or Scarface, it could be cute ambition, a preternatural genre awareness. When 40-year-olds constantly battling to be taken seriously as a director do it, it’s a gigantic setback.

Smith’s has always been too sensitive to people screwing with his scripts that he fatally lacked the sense to screw with this one — Robb and Mark Cullen’s intended homage to the fast-paced urban wit and full-clip action of films like 48 Hrs., Beverly Hills Cop, Fletch, Tango & Cash and Lethal Weapon.

Those who think Cop Out matches up to any of those films are apt to fall for a banana in the tailpipe, too. Cop Out might play a snippet of Fletch‘s end-credits song and have a score by Harold Faltermeyer (of “Axel F” fame), but it more closely resembles the bloat of Another 48 Hrs., Beverly Hills Cop 3 and Fletch Lives.

Smith’s usual verbal spark and snottiness are absent, and the boldest thing here are cojones in a film this bad to suggest something else represents Hollywood’s bowels.

Willis and Morgan’s characters have names — Jimmy and Paul — but they might as well be Hot Head and Wise Guy (as they’re sloganed on the poster). They’re police partners suspended for 30 days after a shootout ends with a dead snitch.

It’s terrible news for Jimmy, whose daughter has a pricey wedding he’s dead-set on paying for. And it will only give Paul additional time to obsess about the infidelity he’s sure his wife (Parks & Recreation’s Rashida Jones) is committing in their bed.

Jimmy’s Plan B is selling a mint-condition baseball card to cover the wedding. But when dopey thief Dave (Seann William Scott, wasted) steals the card and sells it to memorabilia-loving drug pusher Poh Boy (Guillermo Diaz), Jimmy and Paul must find a Mercedes for Poh Boy in exchange for the card. Naturally, they uncover a far-flung conspiracy to make Poh Boy a top-dog drug lord.

Only the musical retro goofs work — an end-credits song by Patti LaBelle called “Soul Brothers” and Faltermeyer’s spectacular synthesized score. But as it becomes clear that all the good bits of Cop Out are in its R-rated trailer, Faltermeyer’s work reminds us of the gangbuster action-comedies we’re not watching.

The PG-rated, 25-year-old car chase in Fletch trumps the one Smith lightly farts out here, and Lifetime Original Movies have better camera coverage on scenes of gunplay. Plus, Smith’s turgid pacing — he edited this mess, too — takes the zip out of Jason Lee, Fred Armisen, Susie Essman, Kevin Pollak and Adam Brody (who shares Judge Reinhold’s beanpole frame but none of his joyfully nerdy presence).

The leads are no less uninspired. Willis plays Jimmy as a lazy John McClane facsimile, and it’s laughably suggested that Morgan’s Paul is a dirty cop. Paul’s dirty only if he’s soiled himself like the grown baby he seems to be. Morgan’s free-rein work here proves he’s really palatable only in 30-minute doses on 30 Rock.

Speaking of 30 Rock, Morgan’s co-stars should get honorary Emmys if they can pretend to have seen, and enjoyed, Cop Out while filming the show with him. After all, it’s hard to imagine any of the fake movies his Rock character has made — particularly Black Cop / White Cop — being any worse.