MotoGP world champion Jorge Lorenzo claims it will be hard to beat Casey Stoner with the Yamaha M1 in its current form - and he doesn't expect a more powerful engine until August.
"Maybe in the middle of the season. Maybe Brno [August 14]," Lorenzo said of a much-speculated new engine, after finishing second to Casey Stoner at Catalunya on Sunday.
Repsol Honda rider Stoner has now won three of the fives races this season, with Lorenzo's only victory coming in the wet Jerez race - in which Stoner was taken out by Valentino Rossi.
Stoner has scored 17 points more than Lorenzo in the last two races, and is now just seven points from the top.
However, Lorenzo understands that Yamaha also has next year's 1000cc bike to develop.
"I would like to fight for wins this year. With this bike it is going to be tough. So I need a little improvement to make the bike quicker," he said.
"But also I would like to fight for wins in 2012. I trust the power of Yamaha to make both bikes competitive."
When asked about any forthcoming chassis developments, Lorenzo made clear he'll be grateful for any assistance.
"I wait for improvements with anything. If its engine I will be most happy. If it's a chassis that gives me some tenths that will be fine, but we need something to fight with Casey at this moment," he repeated.
"There may be some tracks where he is not 100 percent, does not like, or is not able to be very strong. Like Estoril. Then we can fight for the win with what we have."