The incident started out normally enough. Outgoing President Roberto Suazo Cordova said he wanted a U.S. military helicopter to whisk him above bumpy Honduran roads to a remote village where official duty called.

The request was granted as a routine courtesy, U.S. officials said. It was particularly routine for a president who in the last three years has cooperated in turning Honduras into a U.S. staging area and intelligence platform against leftist-ruled Nicaragua to the south.

But then the not-so-routine began. Once airborne in a UH1H Huey from U.S. installations at Palmerola Air Base, Suazo had an aide throw campaign leaflets onto the villages below , including one suggesting that the leading opposition presidential candidate was going around drunk.

Suazo's use of the marked U.S. helicopter two weeks ago, confirmed by closely informed diplomats and Honduran politicians, was an embarrassment to the U.S. Embassy, so much so that the president's next request for a helicopter was turned down.

Suazo also took it seriously. With the story out and Tegucigalpa tittering, his office issued a communique today denying it ever happened. The communique also reported that the Foreign Ministry, on express presidential orders, made a formal protest yesterday to U.S. Ambassador John Ferch, demanding that he turn over the names of U.S. diplomats who the communique said were responsible for spreading the "gross accusation."

Most Hondurans only chuckled knowingly, however, classifying the uproar as the latest in a long list of high jinks and eccentricities in a raucous political race that culminates in general elections Sunday designed to give Honduras its first transition from one elected civilian leader to another in more than 60 years. Along with a president, the voters will choose three vice presidents, 132 deputies to the National Congress and local officials in 284 municipalities.

For the Reagan administration, the unusual conduct of the election may turn out to matter more than who wins the presidency, according to diplomats and Honduran politicians. No candidate with a realistic chance has indicated a desire to challenge the armed forces on their decision to allow repeated U.S. military exercises here and make the country a logistics base for U.S.-sponsored anti-Sandinista rebel forces. Neither subject has been debated openly in the campaign.

But escorting Honduras through democratic elections is an important U.S. goal, these sources say. Collapse of still fragile democratic institutions here could force the military out from behind the scenes, where it now exercises discreet but ultimate power. This, in turn, could generate trouble in the U.S. Congress and make Honduras less attractive as an ally against Nicaragua.

Against this background, many Hondurans and foreign observers have expressed fear the electoral high jinks list may not yet be complete, and that Suazo may have some more tricks in mind before he has to relinquish the presidency to a successor Jan. 27. In the most obvious example, when the country's 1.9 million eligible voters go to the polls Sunday, they will not know for sure the legal rules under which the vote will be counted and the winner declared.

A recently revised electoral law states that the top vote getter within the party with the most overall votes is president. But the constitution states that the candidate with a simple majority is the president, without reference to his party's total. One of the country's major parties has four candidates and the other has three, so it is possible that the candidate with the most votes is not a member of the party with the most votes.

The National Election Tribunal, despite prodding from the U.S. Embassy, the armed forces and the candidates, has refused so far to say what it plans to do about the confusion once the vote is in.

The issue is important for several reasons. Rafael Leonardo Callejas, the National Party candidate whose habits were the subject of Suazo's leaflets, has a good chance of winning the most votes for a single candidate, Honduran and diplomatic observers agree, backed by polls. But Suazo's Liberal Party, with two strong candidates and the power of incumbency, has an equally good chance of winning the most overall party votes, they add, referring to the same polls.

If the electoral law is followed, therefore, the candidate who wins the most votes could lose the presidency, because the runner-up's party got more votes. And if that happens, the law's constitutionality could be challenged in the Supreme Court or in the streets after the election.

Suazo, who is barred from a second four-year term, is cited by well informed diplomats as a key to resolving the confusion. In fact, they and a number of Honduran politicians say the confusion results in part from Suazo's effort to create a cloudy situation that could allow him to remain in power for at least several months more while the outcome of the election is debated.

The seeming contradiction resulted in large measure from Suazo's attempt last spring to prevent aspiring candidates from holding primary elections in the National and Liberal parties, the country's two main political forces. At that point, the wily president was choosing not only his own Liberal Party candidate, but had accumulated enough influence in the National Party to impose its candidate as well.

After a long standoff, the armed forces stepped in last May and sponsored a negotiated compromise that was translated into the electoral law, in effect making the party primaries and Sunday's presidential elections simultaneous. A crisis had been solved, but apparently no one foresaw the constitutional problem.

At that time, the presidential race seemed, in any case, to be between Suazo's handpicked Liberal Party favorite, Oscar Mejia Arellano, and his main rival within the party, Jose Azcona. Since then, however, the youthful Callejas has emerged as a leading candidate with unexpected personal popularity despite his National Party's lag in the polls.

An individual victory by Azcona or Mejia, accompanied by a Liberal Party overall victory, would avoid the constitutional confusion. But an individual victory by Callejas, particularly a solid win without a victory by his party, would open the way for a political and legal dispute that Honduran and diplomatic observers predict would give Suazo room to maneuver for an extended stay in the presidential palace or force the armed forces to intervene openly to prevent violence.

It would not be the first such maneuver in Suazo's record since his election in 1981. The president, according to diplomatic and Honduran political sources, sought last Oct. 24 to transform the National Congress into a constituent assembly in a surprise vote designed to help modify the troublesome constitutional article. But while a legislator was reading the motion at Suazo's command, acording to witnesses, another legislator grabbed at the text, getting into a scuffle and setting off pandemonium in congress.

"It began to look like a soccer match," said one diplomat who was present.

At the same time, reliable diplomatic sources said, the worried U.S. Embassy called the armed forces commander, Gen. Walter Lopez, and urged him to intervene to stop Suazo's plan. Lopez called the congress leader, Efrain Bu Giron, and warned that the armed forces would stand by the constitution, in effect ordering a halt to the maneuver, the informants recalled.

"There could have been people killed in that," said presidential candidate Azcona, in an interview. "We could be under a military government right now."

A National Party leader commented: "This was bound to happen, because we are not used to constitutional democracy. We are used to coup d'etat, coup d'etat, coup d'etat."