Cal Crutchlow focused on improving his feeling with the Tech 3 Yamaha M1 with a full fuel load during the Catalunya MotoGP test in Spain.
Crutchlow, who crashed out of yesterday's race while holding fourth place, experimented with several modifications to his Yamaha.
He clocked the fifth fastest time of the test with a lap of 1m 42.462s leaving him less than 0.2s adrift of the top three.
The 27-year-old British rider also tested a revised-specification YZR-M1 frame previously used by Jorge Lorenzo, but confirmed he will continue to stick with the chassis he has raced with so far this season at the next round at Assen.
“Each time I left the pits today I had a full fuel tank.
"That makes it difficult to make a lap time and it is hard to ride physically,” said Crutchlow.
“I hope we have found something to help me at the start of the race.
“I want to be able to brake a bit deeper in the first few laps and it seems I can do that now.
“I'm sure we have found something because we had a big tailwind today and I could still brake 15 metres later into the first corner than I could in the race when there was a headwind.”
Crutchlow said the revised frame 'isn't any better than the frame I'm on'.
“I tested a new chassis that Jorge used at the first couple of races and it isn't any better than the frame I am on.
“I did the whole day on the new frame and braking stability was better but in other areas it didn't feel quite as good,” he said.
“At the end I went out again on my old chassis and was immediately as fast as before and I was using a set of tyres that had already done 25-laps.
“I felt immediately fast and more comfortable and I will continue to use that frame.”Don't miss out! The next round of the 2013 MotoGP World Championship takes place at Assen on June 27-29 - CLICK HERE to see ticket prices from the Official MotoGP Ticket Store.