James Stewart, Joe Gibbs Racing part ways over Yamaha

It seemed a star-studded marriage: James Stewart, a three-time champion of off-road motorcycle racing, signed a multiyear contract with the Yamaha motorcycle team of Joe Gibbs Racing of NASCAR fame.

The plan also was for Gibbs to provide a path for Stewart to pursue his goal of becoming a NASCAR stock car driver when his motorcycle days were over.

But only seven months after announcing their union, Stewart and Gibbs recently parted ways and Stewart has signed with a new team, Yoshimura Suzuki, for both motocross and supercross. (Supercross is the stadium version of motocross.)

He is scheduled to debut his new Suzuki ride Saturday at the motocross season opener in Sacramento. The season’s finale is Sept. 8 in Lake Elsinore.

Stewart said his split with Gibbs was amicable. “There were really no hard feelings on this thing,” he said in an interview.

So what went wrong?

The 26-year-old Stewart won the motocross title in 2008 by winning every race and the Floridian won the supercross championship in 2007 and 2009. Stewart also is known for being an aggressive rider who often either wins or crashes.

Stewart signed with Gibbs in October, but from the outset Stewart said he discussed with Gibbs’ team how he often was uncomfortable and unbalanced on the newest Yamaha model and that the bike’s design didn’t mesh with his style of racing.

“We had a conversation that this possibly could happen” and that “they knew I had a lot of struggles” on the bike, Stewart said, but added that everyone agreed they could “overcome it.”

They couldn’t often enough. “It had become very apparent that, mentally, James was absolutely convinced that he and that bike were not going to get along,” said Ralph Sheheen, a broadcaster for Speed TV, which carried most of this year’s supercross races.

Stewart did win two supercross races this year, in Oakland and Daytona, Fla., but he missed five of the final six races after being hurt in a crash in a preliminary heat in Indianapolis. He finished the season — which always starts at Angel Stadium in January — seventh in points.

Stewart said he then told Gibbs “I felt like I couldn’t win the championship” on the bike and that “I can do one of two things: I can sit here and collect a check or we can part ways and give you an opportunity to find another rider.

“It wasn’t like I quit, it wasn’t one of those deals,” he said. “They understood.”

Gibbs spokesman David Evans said the team had no comment beyond its brief May 6 statement saying it had “mutually agreed” to part with Stewart.

And Stewart’s NASCAR aspirations? “I think I still have the same opportunity [with Gibbs] as before” to one day drive stock cars, if not with another team, Stewart said. “If I had the right opportunity, I would do it. I left on good terms.”

james.peltz@latimes.com