Opie Bosson has a spring in his step as he approaches Saturday's Caulfield Cup.

But it hasn't always been that way for the talented rider who burst onto the Australian scene as a 17 year-old apprentice to win the 1998 VRC Oaks on Grand Archway.

Weight, and through that a lack of motivation, has seen Bosson take extended breaks from racing's tough environment.

Now the 35-year-old has his weight under control and the motivation is back as he embarks on what he hopes will be a career highlight when he partners $4.40 favourite Mongolian Khan in the Caulfield Cup.

Bosson credits the support of New Zealand breeder Mark Chittick with helping get him on a regime where his fitness and eating habits have improved.

"I went and stayed with him for a while," Bosson said.

"I'd go to the gym everyday and have my meals prepared and then work on the farm with him through the day.

"Previously I was doing things the wrong way with my weight but once I got on a proper eating regime and fitness regime I started feeling a lot better in myself and the weight started controlling itself.

"It was good to get away from racing and get it down properly without having to sweat."

Bosson has continued that ethic and will ride Mongolian Khan comfortably at 55kg on Saturday.

With victories in the New Zealand Derby and the ATC Australian Derby during his three-year-old year, Bosson said Mongolian Khan was looking to return to the 2400m journey.

His three runs this campaign have been excellent, topping it off with a last-start third behind Criterion in the weight-for-age Caulfield Stakes last Saturday.

And another key ingredient was a good draw on Tuesday.

Mongolian Khan drew barrier nine and will start from six if the four emergencies don't gain a start.

"We didn't want to draw one, two or three," Bosson said.

"It will allow us to stay out a little bit.

"He's stepped up with each run and on his run the other day you would expect him to be spot on for this one."