Entertainment

Thai one on!

(From left) BRADLEY COOPER, KEN JEONG, ED HELMS and ZACH GALIFIANAKIS try to put the fun in perfunctory with this awfully famillar sequel. (
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Not generally the biggest fan of gross-out humor, I found “The Hangover” gut-bustingly funny — it re-invented the form with an unpredictable, subversive, take-no-prisoners approach that helped make it the most successful R-rated comedy of all time.

While “The Hangover Part II” will inevitably also clean up, I have the sad duty to report I found this more elaborate, play-it-safe sequel far less fresh or funny. I know a lot of you have been eagerly anticipating this sequel, but please don’t shoot the messenger.

The action has been transposed from Las Vegas to a far more picturesque (and dangerous) Bangkok, where director Todd Phillips and his co-screenwriters struggle to recapture the original magic, sometimes copying the original scene for scene.

And, truthfully, the formerly delightful, twisted camaraderie between the three leads — Bradley Cooper, Ed Helms and Zach Galifianakis — seems more mechanical this time around.

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This time, Helms is the bridegroom-to-be, and he’s taking no chances after the chaos that preceded Justin Bartha’s nuptials in the original.

In lieu of a bachelor party, he holds a brunch at IHOP (one of countless product placements).

Helms even vows not to invite the mischief-making Galifianakis to his wedding, which is being hosted by the parents of Helms’ fiancée (Jamie Chung in the only female role that approaches any consequence) in their native Thailand.

Of course, Helms bows to pressure from his pals to include Galifianakis — obviously a big mistake.

One moment they’re sharing beers on the beach at a resort with the fiancée’s 16-year-old brother (Mason Lee).

The next thing you know, Cooper, Helms and Galifianakis have woken up with hangovers in a seedy Bangkok hotel room, with an alarmed Bartha calling from the resort.

Galifianakis’ head has been shaved and Helms has a face tattoo just like Mike Tyson’s.

Even more alarmingly, Helms’ prospective brother-in-law is missing, except for his ring finger.

Ken Jeong’s effeminate gangster is back, and begins to explain what happened the night before after his obligatory full-frontal nude scene.

Then he keels over, prompting the panicked guys to stash him in an ice machine while they frantically search for the bride’s missing teenage brother.

Anyone who’s seen the original should be able to anticipate what follows well in advance.

The dudes’ adventures involve a capuchin monkey, Russian drug dealers, a transvestite prostitute, a rival gangster (an underutilized Paul Giamatti) and a fairly exciting car chase.

Also figuring in are a tattoo artist (a role intended for Mel Gibson, shot with Liam Neeson and reshot with Nick Cassavetes) — and Tyson singing a particularly excruciating version of “One Night in Bangkok.”

There are definitely laughs to be had, even if the three leads often seem to be going through the motions.

This is especially true of the tired-looking Galifianakis, the first film’s breakout star, whose character this time around seems a lot less outrageous than Jeong, who has been given a much larger role.

It says a lot that the movie’s funniest lines are delivered not by them but by Nirut Sirichanya, as the disapproving father of Helms’ fiancée.

“The Hangover Part II” is certainly watchable. And probably good enough for laugh-starved audiences, if the grosses for “Bridesmaids” are any indication.

lou.lumenick@nypost.com