Kenny Moore, the former U.S. Olympic marathoner and track and field writer extraordinaire, wandered into the dining room of his hotel Sunday afternoon at 2:30, a little bleary-eyed and hungry but psychologically ready to run 26 miles 385 yards.

He had been up much of the previous night writing his story for Sports Illustrated on the first week of Spartakiad, the National Games of the Peoples of the U.S.S.R. Now he wanted a light snack three hours before competing in the marathon, the concluding track and field event of the Spartakiade.

He was optimistic. On a fast, level and smoothly the river one day last week and getting hooked by one of the Soviet anglers who regularly fish off the city's bridges.He had not really noticed the man until his long, cane pole snapped back, and the hook at the end of the line attached itself firmly to the leg of his track suit

"I tried to tell them it was okay, that it was only a track suit, and they should go ahead and rip the prong out. But they held onto me and worked it out very carefully, painstakingly and smoothed it over to make sure it wasn't ruined. They were very concerned.

"He was very upset, and two other men came running over. They grabbed me firmly but gently. They wanted to make sure that I was all right and that my suit wasn't damaged," Moore said. paved course along the Moscow River that he thinks could yield a record time in next summer's Olympic Games, he hoped to run a good enough time to qualify for the U.S. Olympic trials in the marathon next spring in Buffalo.

He sat down with a couple of other Americans, summoned a waiter and tried to order tea and toast. He knew the Russian word for tea, "chigh," but couldn't quite get across the idea of toast.

Eventually, frustrated by the waiter's blank stares, he pointed across the room to a plate of bread and gave a first-rate impersonation of a man putting slices into a toaster, waiting for them to pop up and buttering the results.

The waiter gave a reassuring nod of recognition and disappeared. He returned several minutes later, triumphantly, with a cup of tea, two large pats of butter and a plate of cookies -- some chocolate, some jelly, some sugared.

Moore looked at them, shrugged, but decided not to protest. With stoicism, he ate buttered cookies with his tea.

He told a wonderful story about running along

"It was an interesting counterpoint to the kind of gruff unbending proletarian mentallity so evident in other ways here."

Moore, a thoughtful, sensitive, uncommonly observant man, had noticed, as others have the vivid contrast in treatment of foreigners between Soviet officialdom and the man in the street.

Translators, hotel chambermaids and others in similar low-level support positions hardly could be more eager to please at least until their superiors judge them to be too chummy with foreigners. But officials, especially the middle-level bureaucrats, are quick to say, "No . . . . impossible . . . . it cannot be done." And so it probably will be at next year's Olympics.

That thought came back in the cool of Sunday evening as European champion Leonid Mozeyev of the U.S.S.R. won the marathon in 2 hours 13 minutes 20 seconds, edging second-place finisher Shigeru Sou of Japan and three other Soviets in a remarkable finish that looked more like the end of a sprint than that of a marathon. The five top men burst into Lenin Central Stadium for the final yards of the race practically on one another's heels, and the finish was so close that the top three wound up with the same clocking .

Kenny Moore -- listed in the official entry list and results as "kin Mur," the sort of loose phonetic spelling of English names that has boggled the minds of Westeners competing at Spartakiade -- staggered home in 2:36:57, more than 20 minutes behind his personal best time. Obviously, writing a story, then lunching on tea and cookies, is no way to prepare for a marathon, even on an invitingly fast course.

American athletes and coaches at Spartakiade have taken note of a number of things that they will pass on to their compatriots before the Moscow Olympics.

They have noticed, for instance, that the food here is rather starchy and monotonous, and takes a long time to get served. That that local mineral water tastes like iodine, and the lemonade smells like perfume. That there is a brisk black market trade in American goods especially jeans, tracks suits, sporting equipment and tapes, but that a ruble saved might as well be a ruble burned.

They have noticed that the Soviets are masters of psychology, that they like to televise their athletes when they win but not when they lose. That the man who offers to buy jeans in the middle of Red Square is likely a KGB agent looking for a set-up but that the one who comes to your room might offer $100 and mean it. And that there seems to be a definite Soviet bias in officiating and judging in the Spartakiade that might not go away at Olympics time.

"I like competing over here because they make it very tough for you," said Stan Vinson. "They don't give you the benefit of any doubt. You come here thinking you're at a disadvantage and that gets you that much more psyched to win."

Vinson, 27, a veteran of five previous trips to the U.S.S.R. has won a gold medal in the 400 meters and in the 4 x 400 relays at Spartakiade. An Edge to the Hosts

"Imagine a track meet where the hosts give their athletes the best lane assignments, the best schedule, the best opportunities to win. That's what the Soviets do here. I always come to the Soviet Union aware that they have given themselves every edge and prepared with somethingg -- a little extra conditioning, speed work or something like that -- to surprise them."

Vinson and the other American runners who swept the 400-, 800-, and 1,600-meter relays Sunday to give the U.S. an encouraging finale to the Spartakiade track and field program, were invited to a lunch of hamburgers and french fries at the American Embassy Monday. It was "the first square meal we've had since we got here," said one sprinter.

Afterwards, Vinson went on a private excursion along Kalinin Prospekt, a major shopping street, to take photo and search for batteries for his tape casette player, which had exhausted itself blaring out Donna Summers, Earth, Wind and Fire and other disco sounds for hours on end -- to the delight of the American team and pop-loving Soviets alike.

("All the Russians have been requesting that type of thing," said Vinson. "They told me, 'Bring a lot of Donna Summers when you come back, I even heard her on the radio here, which blew my mind.") Olympic Job Program

Vinson, who ran for the D.C. Striders (now the D.C. international Track Club) for a year and married Washington Paula Smith before settling in Chicago, now works for Wilson Sporting Goods under the Olympic Job Opportunities Programs and trains with the University of Chicago track club. He has traveled hundreds of thousands of miles in a U.S.A. track suit and has competed all over Europe, in China, Japan, Australia, the Middle East, the Caribbean and South America.

"I kind of consider myself a citizen of the world because I've lived under all kinds of conditions and maybe can adjust easier than a lot of people," said Vinson.

He is bright, street-wise and fairly self-sufficient, having majored in interior design, business and home economics at Eastern Michigan University, where he also won the NCAA 400 meters in 1974. He can cook, sew and take care of himself practically anywhere, all while keeping his sanity and an engaging sense of good humor.

"I kind of deal with things as they come," he said. "Most places you shouldn't expect much because that's what you're going to get." Few Sent Best Teams

Most of the 87 foreign countries that accepted invitations to Spartakaide -- normally a competition among teams representing the 15 Soviet republics and the cities of Moscow and Leningrad, but opened to foreigners this year as a dry run for the Olympics did not send their best teams.

The scuttlebutt around the U.S. camp was that number of leading Americans decided not to come when it became evident that their chief Olympic rivals would not be here and that they could make better finanical arrangements at other meets in Europe and elsewhere.

The American athletes at Spartakiade are paid a per diem of 24 rubles a week ( $5 a day) in addition to their room, board and air fare. They would much prefer the money in dollars, since practically everything a tourist might want to buy in Moscow must be purchased with hard currency. But they have been told by the U.S. Amateur Athletic Union that they must take their allowance in rubles.

Most of the Americans who did come -- and the U.S. Olympic men's track and field coach, Jimmy Carnes estimated that 70 percent of his Spartakiade team would be back next July -- never had competed in the U.S.S.R. before. For them, Spartakiade has been a valuable experience. Get Ready to Wait

They know that next year they should bring books, playing cards, tapes and stoic attitudes, for they will find little in the way of homestyle amusements in Moscow. They will know what creature comforts cannot be taken for granted. And they will be acclimated to such Soviet idiosyncrasies as a 30-minute awaiting period in a designated area before all events, intended to assure that one event follows another with precision timing.

"That is something you can tell athletes about, but until they experience it themselves, they won't really know how it affects them and how they should adjust their warmup," said Carnes. "We are better prepared now. These games have served their purpose in that regard. But I wish we had more athletes here."

The Americans who show up next July without competitive experience in Soviet Union, may live to regret it.

"It's definitely a cultural shock coming here," said Vinson. "They are going to find a lot of things that they are accustomed to missing, and if they don't prepare for them before they leave they'll have problems.

"I hope the coaches have taken notes on the weather. It is supposed to be warm and dry here in July, but it has been chilly and wet. If we have the same weather this time next year, the athletes will practically need fur coats."

Most residents and tourists drinks the tap water in Moscow without unpleasant consnquences, but Vinson got sick from it on one of his trips and now drinks only mineral water, tea and soft drinks. And although the local Olympic Organizing Committee has promised a wide variety of diets and prompt service in the Olympic Village -- and shown films of chefs and waiters being scrupulously trained Vinson and other old U.S.S.R. hands remain skeptical. No Language Problem

"We don't have a language problem with meals or taxis or things like that because they understand rubles and dollars perfectly," Vinson went on. "Anything you want to buy, you can make yourself understood. But when you go to the track it's a different story, because we can't even read our names in their alphabet."

Vinson and a number of his conferees expect American, and other unsuspecting foreigners to get "taken to the cleaners" next year by wily Soviets.

"The Spartakiade proved that we have some potential, but things are going to be kind of hectic when we get here," said Vinson. "It was was interesting to note the lane assignments we got: We pretty much knew we were going to be on the extreme outside, either lane 1 or lane 8 every time. And who says they can't control things like that at the Olympics, too.

"They pick the officials, and if you question them it's like saying, 'Okay, this is war. You don't dectate to a country like the Soviet Union, even though the International Olympic Committee is supposed to be in charge.

"In Montreal, we had eight practice tracks. Here there is only one, and every nation on the face of the earth is going to want to use that. The Soviets will have their own track. They have access to facilities the other athletes won't be able to use . For all we know, they may have a track undergoing someplace. They know what they are doing and we don't. 'Slick, Sly Treatment'

"Think about the political overtones of next year, and they're going to get away with as much as they possibly can, and they'll be a slick and sly as they can. It's not going to be detectable. I do think we'll get taken to the cleaners that way.

"I can hear our coaches now, going on TV and crying, "Those guys! Everything is wrong. They're putting us in bad lanes, disqualifying our people, robbing us with their judges.' And the Soviets will be laughing.

"The psych is going to be something else, too," Vinson predicted. "I wouldn't be surprised to see them put some English language shows on radio and TV just so we can understand them, say, 'The Americans are getting beat bad. It's interesting to see how they handled the television of Spartakiade. They wanted to emphasize the events in which the Soviet figured to do well. They showed their fighters beating up on guys. When there was a fight they expected the Russian to win, and an American started tap dancing on his face, they cut right away to another sport in the middle of a round. "Now let's go to swimming...

For these and other reasons, the Americans next summer will set up pre-Olympic training camps, in track and field annd perhaps other sports, in cities outside the Soviet Union. These will be areas where the athletes can be outfitted and complete their training with a minimum of hassle, and they then will fly into Moscow two or three days before their events.

The Soviets resent this attempt to commute, but plans already are underway. Several sites have been considered, with well-equipped facilities in Oslo and Zurich the most likely to be chosen. Two assistant coaches were dispatched this week to examine other possible headquarters in Finland and Sweden.

"The Soviets really don't appreciate the idea, but it's good for the athletes. We'll do our own thing," said Vinson. CAPTION: Picture 1, At Spartakiade, marathon runners cross bridge near St. Basil's Church; Picture 2, winning 400-meter relay team of Cliff Willy, Rich Edwards, Warrell Gilbert and Don Coleman share smiles; Picture 3, Stan Vinson, wins 400- meter final; Picture 4, bird's-eye view of Lenin Stadium, Picture 5, Henry Marsh hails steeplechase victory. UPI