Casey Stoner and his Repsol Honda crew were forced to subdue 'huge' chatter from the world champion's RC213V on their way to setting the Thursday night free practice pace for the season-opening Qatar MotoGP.

The Australian was the only Honda rider in the top four, having moving ahead of Yamaha's Jorge Lorenzo on the twelfth of his 13 laps.

Stoner, who has battled chatter issues at the Sepang tests but not at the final pre-season outing in Jerez, said:

"The track tonight wasn't so bad, I expected the conditions to be much worse but in general it was ok. We started this evening with huge chatter issues and I was a little afraid we couldn't fix this, but after a few more exits we managed to reduce it to a more comfortable level.

"This is a positive point for the weekend but with such a short session and then nothing until tomorrow it's slightly strange. It was an ok start tonight, we finished quickest which is good, but we'll have to wait until tomorrow for some real track time and with the conditions a little better and see where we are."

Team-mate Dani Pedrosa also experienced chatter problems during his first RC213V laps at the desert track, plus other complications that left the Spaniard in fifth place, 0.656sec from Stoner.

"There are some corners where we are struggling a lot with the chattering, especially in the area where you slide more, but it's like this and we will need to adapt the best we can.," said Pedrosa.

"On my first exit I had an issue with the tyres and I had to stop in the garage; I felt a vibration in the wheels, so we decided to change both tyres. I lost some time there and at the end of the practice I went wide twice.

"Anyway, it's been good to go out there and get the feeling back at this track after a long time without riding here. Tomorrow, with two practices sessions, we will start working more with the chassis and electronics to improve and prepare for the race".

The Qatar action continues on Friday with two more practice sessions to prepare for qualifying on Saturday.