Gene Wilder might enjoy a long, distinctive career as a comic star if he could invent clever variations on the basic character type he played in "The Adventure of Sherlock Holmes' Smarter Brother."

In that minor but pleasant and savory farce the humor grew out of a role that suited Wilder's style: the frustrated kid brother of Sherlock Holmes, as keen of mind as his famous sibling but somehow uncoordinated when it came to putting his expertise into practice.

Wilder's new movie, "The World's Greatest Lover," his second venture as star, director and writer, is not very clever at all. Quite the antithesis. Wilder demonstrated more finesse and awareness of how to exploit the strong points in his comic "sherlock Holmes" personality.

Opening today at area theaters, "The World's Greatest Lover" is cause for alarm. Wilder seems to be forgetting more than he's learning.

The prevailing tone of "Lover" is shrill wretched excess, in both slap-stick and sentimental passages. It's closer to the sort of thing Marty Feldman did in "The Last Remake of Beau Geste" and that one might have expected in Wilder's first feature, when he was coming straight from a collaboration with Mel Brooks.Wilder stiffs his new movie with smut filched from the Brooks cupboard. He also exercises his tongue, eyes and facial muscles so frenetically that he begins to resemble Feldman.

A romantic farce set in Hollywood in the '20s, "Lover" evidently began with a premise that might have worked: Wilder as the stand-in for Rudolph Valentino. One can imagine this identity serving his purposes. It could have rationalized the kind of frustration, role-playing and pathos he seems equipped to express.

It might also have rationalized a funny love match with Carol Kane, whose bug-eyed, ethereal charms would appear to make her an ideal romantic companion for Wilder.

I don't know when this viable premise was discarded, but the finished film collapses partly for lack of a foundation.

Wilder and Kane play ingenuous newlyweds from Milwaukee who travel to Hollywood when he decides to enter a talent contest sponsored by a manic studio boss (Dom De Luise in a role and performance modeled much too closely on the Zero Mostel character in "The Producers") seeking a rival to Valentino.

The plot is so poorly organized and coordinated that one does a double-take when the leads turn up as a married couple. They've already been introduced in ways that would suggest unacquainted wide-eyed innocents destined to be brought together, and the story would be better if they were dreamy pilgrims who met in Hollywood, the place where their dreams were being manufactured.

Having located the newlyweds in Hollywood, Wilder proves unable to coordinate their activites.He loses track of the talent contest for quite a while, then sends Kane on a diversionary subplot recollected from Fellini's "The White Sheik" but exploited for revolting masochiastic pathos, with the hero supposedly serucing his own star-struck wife while disguised as her favorite star.

Wilder betrays uncertain taste and shaky technique from the start.

De Luise opens the show on a crude, noisy, hysterical downbeat. Wilder gropes for laughs in his first appearance, performing a tango in Valentino's costume from "The Four Horsemen of the Apocalypse," and as the movie trudges on, the groping becomes more anxious and presumptuous. Kane is introduced adroitly: Seated in a movie theater, she recoils as her screen hero, supposedly Valentino, is slapped. However, moments later Wilder violates the comic integrity of this conceit: The torturer smashes Valentino in the crotch with a mace and Kane doubles up.

Besides not knowing how to get started, Wilder doesn't know when to let well enough alone. He also presumes to jerk tears on totally unjustified grounds. When he puts lines like "Forgive me, forgive me, forgive me!" in his smarmy character's mouth, you want to shout "No! No! No!" By the same token, when he alludes to "All the pain I've caused you," the appropriate audience response would be, "You can say that again!"

His most agreeable notion has been to provide roles for several veteran character comedians. Fritz Feld, cast as a hotel manager, is the most prominent and recognizable, but familiar faces and voices keep popping up in almost every sequence. The best single comic performance is contributed by Ronny Graham as a frazzled movie director in the tradition of the Douglas Fowley character in "Singin' in the Rain." Graham's character is beginning to head around the bend as a consequence of directing 4,000 screen tests with prospective new Valentinos in a single week.

The following didication appears at the end of the film: "A loving thank you from Gene Wilder to his friend Federico Fellini for the right word of encouragement at the right time." Under the circumstances a right word of discouragement might have saved everyone a lot of grief.