Robert Stolarik for The New York Times

About a year ago Mikael Tarkela heard some disturbing news about the 1976 Peugeot 103 moped that he had been storing in a warehouse in Bushwick, Brooklyn.

A friend called to tell him that the bike had vanished, apparently stolen. Mr. Tarkela, 35, was crestfallen. He had found the Peugeot in a garage in California when he was 19 and restored it to running condition. In Los Angeles he had joined a moped gang, The Late Birds.

A week after the phone call, the friend called again, to tell Mr. Tarkela that the moped had reappeared. It seemed still to be in good working order. Mr. Tarkela, a graphic designer, rejoiced. Then he decided it was time to take the trusty 100-pound moped on an epic trip, the sort of journey that he would remember for years.

On Sunday afternoon, he stood on a sidewalk on Kent Street in Greenpoint, preparing to head off on a 4,200-mile ride to Los Angeles, passing through the hills of West Virginia and Kentucky and the flat, arid lands of Arizona and New Mexico, sticking to the sort of local roads most suitable to the moped’s top speed of about 35 miles an hour.

He secured surplus green canvas military bags to the modest frame. He lashed bright red plastic gas canisters to a rack on the back. Passers-by paused to gaze at the sight of a short-range vehicle being outfitted for a long-range trip.

“I’m heading west by God’s providence,” Mr. Tarkela said. “People are asking me why I don’t get rid of the moped and buy a motorcycle, but everyone does this trip on a motorcycle.”

It is not the first time he has embarked on an unusual undertaking. Two years ago, Mr. Tarkela said, he hitchhiked through Finland. And for seven weeks this spring he tried to experience some of what it might be like to be homeless, sleeping in different spots, carrying possessions in a plastic bag and limiting himself to a few dollars a day for food. The effort left him exhausted, he said, and he is planning an art installation combining that experience with whatever transpires on the cross-country trip. The common theme, he said, will be doing things that are uncomfortable.

Mr. Tarkela was approaching the trip with a bit of trepidation, he said, noting that he expected to push the moped up steep mountain roads and thought he would have to make frequent stops to ease the strain on the small two-stroke air-cooled engine. He said he planned to sleep outside under a tarp and wondered how he would fare in the intense heat of the desert.

“I’m really flipping out thinking that the road is going to cook my tires,” he said. “And I’m a little afraid of snakes.”

Mr. Tarkela said he would document his trip with photographs and post Twitter updates at @slackrabbit.

As he readied the moped Mr. Tarkela inventoried his supplies, including sunscreen, a leather jacket, a roll of toilet paper, duct tape and goggles like those a World War I aviator might wear. He had a cooking stove fashioned out of a soda can; $8 in his pocket; two books, “Zen and the Art of Motorcycle Maintenance” by Robert Pirsig, to help him overcome obstacles, and “The Road” by Cormac McCarthy, to remind him that the obstacles he encountered could always be worse.

He said he hoped to take hardships or unexpected deviations from his plan in stride. And, indeed, he had already made a major change before the trip even began.

Initially, Mr. Tarkela said, he intended to leave New York City through the Holland Tunnel. But he decided the sight of a man with a bandanna dust mask across his nose and mouth while driving cans of gas into the tunnel might attract unwelcome attention from the authorities. So he enlisted the help of two friends, Matthew Beighley and Jacqueline Santillan, who agreed to drive him to New Jersey in a van.

“I’m pretty sure this is going to be an awesome trip,” Mr. Tarkela said. “Even if I only make it to the Appalachians and the bike explodes.”

In the days since leaving Brooklyn, Mr. Tarkela’s Twitter posts reflected relatively smooth progress. He spent his first night camping in a yard in North Plainfield, N.J. The next day he crossed into Pennsylvania, where he repaired a hole in his sock with duct tape, got lost, found Valley Forge, watched Amish farmers in their fields and discovered that a day of riding caused him to “walk like a drunk.”

But the quixotic trip apparently was also taking a toll on the moped. On Wednesday, while passing through Reamstown, Pa., he wrote, “My bike and I do not like the 90 degrees plus weather.” And on Thursday, while preparing to enter Maryland, he announced a break for repairs.

“The subtle shake in the bike has me concerned,” he wrote. “Taking the day off to clean and maintain the piglet.”