It’s feast or famine in Balagan Theatre and Seattle Musical Theatre’s coproduction of “Urinetown,” a staging that has almost as many rousing moments as it does ones that fall flat. The 2001 musical about a dystopian world where private toilets have been outlawed is no stranger to Seattle stages, making this lopsided production from two theaters in transition feel even less essential.

Director Jake Groshong has assembled a strong ensemble, most evident in the snappy “West Side Story” knock-off “Snuff That Girl” and the soaring gospel harmonies of “Run Freedom Run.” “Urinetown” is a better show when it embraces musical-theater convention than when it tries to flout it, and the ensemble, led by choreographer Teri Spero and Jeff Orton, makes the most of these moments.

Unfortunately, the lead performers aren’t quite as uniform in their vocal qualities and comedic timing. As Bobby and Hope, Frederick Hagreen and Molli Corcoran have the strong voices and artificially pumped-up enthusiasm to make them ideal parodies of musical-theater leads, but Michael L. Warner’s villainous Caldwell B. Cladwell isn’t remotely imposing, vocally or otherwise.

Even though “Urinetown” is just over a decade old, the blatant self-reflexivity of its narration from Officer Lockstock (Doug Willott) already feels passé, and Willott doesn’t wink nearly hard enough to sell the meta humor.

Too often, the book stops at merely identifying theater tropes, and it takes a comically dialed-in cast to wring out actual jokes at the expense of those tropes. For all of its strengths — throw in the admirably grimy set and lighting from Jared Roberts and Ahren Buhmann — this “Urinetown” has a serious laughter shortage.

Dusty Somers: dustysomers@gmail.com