Last year Olympian Kenny Moore of Eugene, Ore. won the first Marine Corps Reserve Marathon, through streets and parks of the District and Northern Virginia, in 2 hours, 21 minutes, 14 seconds. That was 9:39 below his career best time, primarily because he got lost near National Airport and ran more than the true Olympic distance of 26 miles, 385 yards.

Moore is not back for today's second Marine Marathon, which starts at 9 a.m. at the U.S. War Memorial (Iwo Kima Monument). No runners of Olympic stature are entered and the world record of 2:08:33 will not be threatened when the leading men return to the start/finish line at about 11:20 a.m.

Nevertheless, the field has tripled from last year to upwards of 3,300 runners - second only to last month's New York City Marathon as the biggest in the U.S. And it is unlikely that anyone will lose his or her way, because both the course and the race organization have been improved tremendously.

A new route, painstakingly plotted to maximize majestic scenery, has been marked with a 26-mile line of blue chalk and will be patrolled by 140 guides in red vests. Turns are designated by traffic cones, and three policemen on motorcycles will precede the lead runners.

Such planning typifies the wide-ranging logistical and organizational improvements, from control of the pack at the starting line to efficient channeling of runners and recording of times at the finish, which distinguish this Marine Marathon from last year's somewhat chaotic inaugural, described by one officer as "a comedy."

"Last year we didn't quite know what we were doing. We had no experience. But we learned from our mistakes," says Major Jerry Drucker, the race coordinator who has been working with a battalion of military and civilian volunteers, from Marine reservists to Amateur Athletic Union Officials to police and the Girl Scouts.

Consquently, Washington's marathon has suddenly become a "People's Race" which many think could blossom swiftly into national prominence and popularity.

As of the start of registration Friday, 3,356 entries had been received, representing 32 states, Canada, Great Britain and Australia. Last year 1,176 runners started and 1,055 finished.

The field ranges in age from seven-year-old David Levri of Rockville (who will run with his father and three older brothers) to 70-year-old John Planfetti of Charleston, W.Va.

It includes on footless runner (Peter Strudwick, a California teacher who finished in 4:48:06 last year), one wheelchair athlete (Cindy Patton of Boston, paralyzed from the waist down in a 1976 skiing accident), one Congressman (Rep. Lionel Van Deerling of California, who has never run a marathon but once competed in a 50-mile race), and one Presidential speechwriter (Jim Fallows, 28, who last ran in the 1969 Boston Marathon as a Harvard undergrad, finishing 150th in 3:12).

Among the favorite are Phil Camp, a Navy helicopter pilot from Pensacoia, Fla. whose 2:18 is the best career effort of those entered; Alexandria neighbors Max White (2:20 best time) and Peter Nye (2:31); and Kevin McDonald of Greenville, S.C., who ran 2:20 to finish 25th at Boston in 1975, when Bill Rodgers set the U.S. record of 2:09:55.

If Camp is not in top shape, many knowledgeable local runners expect to see a duel between White (2nd in Boston this year at 2:23:56) and Nye, who expects to improve substantially on his Boston time of 2:46:10 (34st place.)

"I'm ready for a low 2:20," says Nye, who has been training 100 miles for the last 10 weeks. "This course is fast because the pavement is smooth and it's level. It's the kind of course on which you can click if you're feeling good. There will be a lot of best personal times here."

McDonald, 27, a former baseball pitcher and hockey player who only started running competitively in 1973, did 2:21 in last year Olympic Trails, but has been inhibited in his training (90 miles a week) by a chronic hip problem.

Among the 125 women competing, Susan Mallery, a native of Arlington who is now an Ohio State grad student living in Columbus, is the clear favorite. She won the women's title here last year in 2:56:33 and was under three hours in a "training run" at Monroe, Ohio, three weeks ago.

"I've been training 80 or 90 miles a week. I'd love to come up with a good time here because it's the old hometown," said Mallery, 23, a graduate of Washington-Lee High School.

There are no world class runners here this year, chiefly because the U.S. Dept. of Defense Code of Standards precludes commercial sponsorship of the race or payment of the expense money it would liegly take to a field comparable to New York's which included most of the world's best marathoners.

"Our race is, of necessity, one of the last true amateur sporting events," says Maj. Drucker.

Last year's problems did not help in recruiting top runners, and the proximity of the date to New York's undoubtedly hurt the quality of the entry. Even though more than 1,000 Washington area runners are entered, such top ones as Dan Rincon and Bruce Robinson (26th and 28th New York, respectively) are sitting out.

Nonetheless, there is optimism at Marine Headquarters and in local running circles that this marathon, like Boston with it 81 years of tradition, will eventually draw world class runners simply because they want to be a part of it.

Marathons are charaterized by their courses - Boston's "Heartbreak Hill" (actually a series of four slopes) and New York's five-borough trail through diverse ethnic neighborhoods, for example - and it is easy to envision the Marine Marathon becoming nationally popular as "the run through the monuments."

Spectators also make marathons memorable. Crowds were estimated at one million in Boston this year, 800,000 in New York, lining the entire route. Only a few hundred watched here last year, but more than 3,000 are expected today at the Iwo Jima monument alone, and thousands more at such primes spectator points as Key Bridge (9 miles, 9:45 a.m.), Lincoln Memorial (11 miles, 10 a.m.), the U.S. Capitol (13 miles, 10:15), and Hains Point (20 miles, 10:50), where a fire boat will be pumping colored streams of water.

Runners will be psyched up and spectators entertained by music at strategic points: the 65-piece Marine Drum & Bugle Corps at the Iwo Jima Monument, the 120-member Wakefield High School Band at the Pentagon, a 15-piece Bagpipe band at Lincoln Memorial, and ensembles from The Bayou, Crazy Horse and Pall Mall outside those establishments in Georgetown.

The stirring bells of the Dutch and Taft Carillons will be played, and the theme from "Rocky" will greet runners in need of a surge of inspiration at the Jefferson Memorial, the 18-mile point.

There are a number of first-time marathoners running, including many who have attended marine-sponsored clinics on training. Most of these want only the internal satisfaction of knowing they can withstand the fabled "wall of pain" that hits even the fittest athletes at about 20 miles, overcome the stress on the system that increases almost geometrically the last six miles, and finish.

Some are trying to qualify for Boston (then must better three hours, women and age groups various slower times, to become eligible for the country's oldest marathon). Only a few have any hope of winning the Mittendorf Trophy (donated by former Navy Secretary J. William Mittendorf II), Symbolic of the open championship, but there are also awards for the top four men and women in several age brackets (15-and-under, 19-and-under, 20-29, 30-39, 40-49, 50-59, 60-and-over); the top military, university, high school, women's and club team and the top finisher among the 700 Marines entered.

"We have just about every age group and occupation imaginable participating, including nine clergymen - I think that qualifies as an ecumenical happening," said race director Col. Jim Fowler, who asked one of them, Father Joe Shea, to arrange for good marathon weather; no precipitation and temperatures below 60 degrees.

"And for everybody, of course," Fowler added, perusing the starting roster that included 36 accountants, 153 attorneys, 1,023 military personnel, five pharmacists, 10 writers, 13 bankers, 59 salesmen, three biologists, 290 students and one cook, "there's that personal religious experience that comes at about the 21st mile."