It sounds like an episode of Seinfeld: That lovable goofball Kramer accepts the nomination of the Libertarian Party, hires Jesse Ventura's campaign manager and makes a bid for mayor of New York.

Except that it's all true.

Kenny Kramer, the inspiration for Seinfeld's spastic neighbor, Cosmo Kramer, is making a serious bid to be the next chief executive of one of the world's largest and most important cities. He won the nomination of the Libertarian Party of New York in late April and has signed on the campaign manager who astounded everyone by helping to make an ex-professional wrestler the governor of Minnesota.

"I think I really have a shot," Kramer said recently in the bus that serves both as the centerpiece of his Seinfeld-based tour business and as his campaign vehicle. "I'm not a politician. I don't have a bunch of cronies. And in my administration there would be no scandals because I admit to everything."

Recounting the Bronx native's urban adventures could take a while. A one-time stand-up comedian, inventor of light-up disco jewelry, voice-over actor for adult CD-ROMs, karate coach, reggae-band manager and coloring-book promoter, many of his exploits with Seinfeld co-creator Larry David became plot lines in the acclaimed NBC sitcom. On weekends, Kramer now runs the Kramer Reality Tour, in which he takes tourists to spots where real-life events in his own life became Seinfeld episodes.

The part of his past that may hurt him most, however, is his previous attempt to win the Democratic nomination in the last mayoral race. In that campaign, the primary plank in Kramer's platform was his promise to equip Gotham's homeless with cellular phones so it wouldn't be so obvious they were talking to themselves.

"It was really just a publicity stunt," he said. "There was no one who was going to beat [current New York mayor] Rudy [Giuliani]. But I'm not kidding this time."

Although he's still forming a policy committee, Kramer said that he'd like to cut down on bureaucracy, see a new stadium for the Yankees in Midtown — but only if it's entirely privately funded —and try to bring the Olympics to the city in 2012. A registered Democrat, he also said that he'd retain the Republican Giuliani, whom he considers a friend, as an advisor.

Campaign manager Douglas Friedline said that Kramer's biggest asset and his biggest deficit are his celebrity.

"At face value, he's not considered a serious candidate," he said. "But neither was Ventura."

Friedline is generally credited for the outspoken wrestler-turned radio host's upset victory in the Minnesota gubernatorial elections as a Reform candidate. Later this week or next week, Friedline will officially announce that he's heading up Kramer's mayoral effort, suddenly planting Kramer's dreams of the mayoralty firmly in the outer fringes of possibility.

"When Ventura got into the debates, people realized they finally had someone willing to speak at their level," Friedline said. "I think Kenny can be close to that. Kenny can relate to people. If you put him in a debate with [city comptroller and Democratic contender Alan] Hevesi and [media baron and potential Republican nominee Michael] Bloomberg, Kramer's going to steal the show."

Much of Kramer's chances will depend on whether he can raise $250,000, the amount he needs to make for the government to kick in four-to-one matching funds. And even then, Kramer admitted, he'll be fighting on uneven ground against the entrenched New York City Democratic machine and Bloomberg's estimated $20 million war chest.

"I'll be the ninja candidate," he said. "I can't afford to buy pages in The New York Times, so I'll buy in the Village Voice. I'll run a street-level campaign. I'll speak at high school graduations. People will see I'm for real."

At least one election expert doubted that would be enough.

"His chances are zero," said Hunter College political-science professor Kenneth Sherrill. "Kenny Kramer is newsworthy, he's flamboyant, he'll be fun to watch, some of the ideas he may articulate may get into the political discourse. But you need more than a slick media campaign to run a mayoral election. It should be viewed as merely an ego trip. He's not going to win."

Even Libertarian Party chairman Richard Cooper said he's realistically hoping not so much to take City Hall as to merely put his party on the New York City map.

"If you run anyone with a fair amount of name recognition, you should be able to get two to four percent of the vote," he said. "If we run a decent campaign, we'll have three to four percent, even maybe 10 to 12.

"But if it catches fire, who knows?" he added.

On Sunday, Kramer made his first public appearance as a mayoral candidate since his Libertarian nomination at a marijuana rally in Battery Park. Diving into what was more stand-up than stump speech, he had to wrestle back the crowd's attention when police in another section of the park arrested a protester for smoking pot. Kramer didn't get to fully articulate a message he'd wanted to address to the public an hour earlier, in his tour bus-cum-campaign bus.

"Whether or not you support what I'm doing or not, I need your help just to get in the game," he said. "I'm going to work very hard, and people are going to take me seriously."