Sylvia ? After a little bit of tweaking to his single-engine RV-3, veterinarian Bob Vasey believes he’ll be ready for the Experimental Aviation Assn.’s AirVenture Cup.

“It’s an awful lot of fun,” Vasey said. Last year, he and his son won their division in the event flying in his son’s two-seat plane.

For this year’s race, Vasey has modified his RV-3, adding a spare 8.8-gallon gas tank so he can make the race from Kitty Hawk, N.C., to Oshkosh, Wis. “It would be embarrassing to have to stop and pick up gas,” he said.

After some final tweaking to the tachometer, an instrument that measures engine revolutions, and the Global Positioning System, the plane will be ready for the July 27-28 race.

Vasey learned to fly when he was “very young.” Six of his uncles were pilots; one daughter flies, another is a flight attendant, a son-in-law is a Delta Airlines pilot, and a son sells planes for a living. But at age 71, Vasey hasn’t considered retiring from his veterinary work so he could have more time to fly.

“I’ve got to support my habit,” he said. “And if I ever do retire, I have plenty of projects.”

Ferald Fox, of Lewis, Vasey’s friend and fellow Experimental Aviation Assn. member, has built five planes from RV designs.

“It’s something that bites you, and you have to scratch it,” Fox said.

Building a plane is vastly different from buying one, he said. Homemade, Fox said, is more fun and, in many cases, better than store-bought.

“On a store-bought plane, you have a lot more red tape,” he said. “You have to keep up with the modifications that come along.”

Vasey’s RV-3 — which carries the initials of designer Richard Van Grunsven, the admired icon for do-it-yourself builders — is “good and tough,” Fox said. “It’s not a showstopper, but he’s got to be happy with it.”