Every trip Craig Williams makes to Werribee to partner his Caulfield and Melbourne mount Admire Deus the better understanding he gets of the stayer.

Williams rode the Darren Weir-trained Japanese import at the Werribee quarantine centre on Tuesday, the fourth time he's been aboard Admire Deus since his arrival in Australia.

The champion jockey first got to ride Admire Deus in Japan before he entered quarantine for his trip to Melbourne.

The Australian Bloodstock-owned Admire Deus has been at Werribee for almost two weeks and finishes his stay on Saturday before heading to Weir's stable for the week leading up to the $3 million Caulfield Cup (2400m) on October 21.

Williams said Amire Deus, an $11 chance in the Caulfield Cup and equal second favourite at $13 for the Melbourne Cup, was a strong and determined stayer.

"He's got amazing capacity, a great motor and I think Darren's going to be very happy with where he's at," Williams said.

"He'll decide on what's going to happen when he comes out of quarantine on Saturday but I'm looking forward to hopefully partnering him again."

Williams said the stable had been tinkering with Admire Deus' gear ahead of the Caulfield Cup.

Admire Deus has been working with ear muffs, without ear muffs and a different thickness of ear muff.

"If we use Formula One terminology he's got a great motor and they're just tinkering with a couple of things," Williams said.

"He's lived his whole life with ear muffs on.

"I'm confident they've got the right tools and the right machine and it's just tinkering with getting what will work on race day right."