Kristen Hall-Geisler for The New York Times

EUGENE, Ore. — On Aug. 12 at 8:20 p.m., Nathan Fillion, star of ABC’s “Castle,” sent the following Twitter message: “I found it! I found my spaceship! It’s real and I’m getting it! //arcimoto.com/”.

That night, at 10:26 p.m., someone at Arcimoto, maker of the Pulse electric vehicle prototype, sent a Twitter message of its own: “@NathanFillion And that, friends and neighbors, is how you crash a Web site. You da man! We’ll be back up soon.”

And that is how a man with more than 600,000 followers on Twitter overloaded the servers of a small electric vehicle start-up.

Last Saturday, on a warm, hazy afternoon, Mr. Fillion took a step toward fulfilling his Twitter message. He and a “Castle” co-star, Jon Huertas, visited Eugene, where Arcimoto is based, to test drive the “spaceship.” Both actors are in the market for a personal electric vehicle they can use to drive to work.

Arcimoto says it plans to begin limited production of the Pulse in early 2011, and it is expected to have a retail price of about $17,500.

Classified as a motorcycle, the Pulse is a three-wheel all-electric vehicle with a top speed of 65 miles per hour, Arcimoto said. Its lead-acid batteries can recharge in about six hours, and it can travel about 40 miles per full charge. It has two seats, one directly behind the other; the second seat folds flat for cargo.

“It’s the excitement of a motorcycle without that ‘Oh God, I’m going to die’ feeling,” Mr. Fillion explained. “This is bigger than it looks, and it has a stable platform.”

The final version of the Pulse will have an electric DC motor powering the front wheels with the equivalent of 65 horsepower and 85 pound-feet of torque.

The first versions will use lead-acid batteries, which are much cheaper than lithium-ion batteries. But Arcimoto’s founder, Mark Frohnmayer, called the Pulse “battery agnostic,” meaning that as lithium power packs become more affordable, or the consumer becomes more wealthy, the lead-acid batteries can be easily swapped out for more advanced cells with a longer range — up to 160 miles.

Mr. Fillion and Mr. Huertas were looking for enclosed electric motorcycles online when they came across the Pulse.

Mr. Huertas liked the three-wheeled design for being close to a motorcycle but with extra protection. He noted that the design made the vehicle lighter and more efficient than a car, and it put less rubber in contact with the road.

The actors tested a Pulse prototype — the fourth one built by Arcimoto. It had a motor, frame, two seats and not much else.

Mr. Fillion sent Twitter messages to his followers throughout his tour and test drive. He posted photos, took questions and sent a quote from Mr. Huertas when it was his turn at the wheel: “I feel like I’m driving a shark!”