Castrol Honda's pre-season Kyalami test ended early on Thursday following heavy rain at the South African track but only after new signing Tadayuki Okada set the fastest time of the day to equal the lap record.

"We more or less got the machine how we wanted it yesterday then set about testing some tyres today," said the 33-year-old Japanese rider. "I wasn't too bothered about the time but it's always nice to be somewhere near the race pace.

"We made a couple of changes to the front forks this morning then settled down to some tyre testing this afternoon."

Okada has completed 140 laps of the track during the opening two days of the four-day Michelin tyre test, recording a best lap on Thursday afternoon of 1m 43.2s.

World champion Colin Edwards took on some major changes to the Castrol VTR and the American is confident of further improving the 2000 title-winning machine.

He said: "It's the Kyalami circuit that's forced us to look at the machine set-up. Unlike Phillip Island in December where we ended up with a good setting, Kyalami has a lot of slow, bumpy corners and combating that is the area of set-up we are concentrating on.

"I've still to try any of the new Michelin tyres although I was heading for that this afternoon until the rain came."

Edwards recorded a best lap of 1m 43.7s, marginally slower than his opening day fastest lap of 1m 43.3s.

Castrol Honda's Chris Vermeulen continued his progress on the new CBR600F Sport machine, improving his best lap of Wednesday's opening action by 0.8s.

Vermeulen said: "Michelin gave us a load of tyres to try and everything's going fine. I tried both machines today, the number one and the spare, we got the suspension right and both engines feel fast. I seem to have done a lot of laps today but I'm very happy with our progress."

Vermeulen's best lap on Thursday, of 1m 48.0s, is 0.3s faster than the lap record, set in 1999 during the South African World Supersport round.