Yamaha's reigning double MotoGP champion Jorge Lorenzo finished the first day of 2013 testing just 0.008s behind Honda's Dani Pedrosa at Sepang on Tuesday.
After readjusting to MotoGP speed following the winter break, Lorenzo began evaluating chassis and engine parts, but the results were inconclusive.
“It was good got the first day. It is always difficult to get the feeling back of riding a MotoGP bike, but it was easier this year,” began Lorenzo.
“Then when I gained the pace we started to try new things that we couldn't try and Valencia and Aragon [due to poor weather last November].
“Some parts I liked, some things need more work. It is still not clear. Tomorrow we are going to keep trying the things we tried today, plus some new parts.
“Things are very close between Yamaha and Honda," he said of the factory M1/RCV dominated top four. "We will try to improve our bike.”
Lorenzo's main aim is to improve acceleration and reduce 'pumping' movement when the power is applied.
“Even if we improved last year quite a lot, acceleration is not our strong point,” said Lorenzo. “We also have a bit of 'pumping' when we open the throttle. That is what we will try and improve.
Lorenzo stated that the performances of Repsol Honda rookie Marc Marquez and his own returning team-mate Valentino Rossi - third and fourth respectively - had not been not a shock.
“I wasn't surprised because I thought Valentino and Marquez will be there from the beginning,” he said.
Just 0.044s covered Pedrosa, Lorenzo and Marquez on Tuesday, with Rossi 0.427s from the top.