Valentino Rossi says the first six races of the 2014 MotoGP season will decide whether he should retire at the end of the year.
The seven-time MotoGP champion was outpaced by team-mate Jorge Lorenzo on his return to Yamaha this season after two unsuccessful campaigns with Ducati.
Rossi sacked his long-time crew chief Jerry Burgess during the final round of the 2013 season at Valencia and has now given himself a deadline to show sufficiently improved form to make it worth staying in the series.
"It will be hard," said Rossi in an interview with Italian broadcaster MediaSet.
"I honestly don't know if I can do it by changing chief engineer, but this is the right moment, because from February to June there is testing and the first six races, and I'll have to decide whether to carry on or quit with MotoGP, so I need to make a step forward.
"I'd like to continue, but I'll continue if I'm competitive."
The 34-year-old Italian said he wants to race on with Yamaha at least until the end of the 2016 season if he can show better form.
"Today I can tell you that if next year I can be a bit more competitive than this year, then I'd like to carry on for at least two more years," he said.
"I've already talked to Yamaha and this is my objective, after which I think it'll be over because I'll be 37 and the time will come.
"But if next year I go like this year or even worse, then I could decide to quit."
TYRES A FACTOR IN DECLINE
He believes the current generation of Bridgestone tyre compounds has been a factor in his loss of pace, particularly compared to Lorenzo.
"He's managed to ride with precision, very smooth from the first lap out of the garage with cold tyres, going very quick and making almost no mistakes," said Rossi.
"I've always chosen and have always preferred hard tyres. Now the hard tyres are not there anymore: I've had to adapt to softs."
On Wednesday Rossi officially launched the VR46 Moto3 team that he has established with former Ducati team boss Vito Guareschi.
But he denied that he was looking to switch to team management full-time when his riding career ended.
"I'd like to race. I can follow VR46 even if I race," said Rossi.
"We have many things to follow but I'd like to race in bikes or cars."
Translation by Michele Lostia