Valentino Rossi has admitted that he is struggling to get his factory Yamaha YZR-M1 adapted to the new Bridgestone tyres.
Under the single tyre rule introduced for 2009, only two different spec front and rear compounds are made available to riders.
Some thought it would favour the likes of Rossi more, given that equal equipment would allow rider talent to shine through more.
But the 30-year-old Italian, who goes into this weekend’s Spanish GP in Jerez chasing his first win of the season, has not yet completely clicked with the new rule.
He was comprehensively beaten by Ducati rival Casey Stoner in the season’s opening race in Qatar and then suffered a close defeat to Fiat Yamaha team-mate Jorge Lorenzo at last weekend’s Japanese GP.
Rossi told MCN: “With these tyres, they don’t change massively, but they have changed.
"We have some problems and we are not fantastic and I can’t ride how like I want to. It will be interesting this weekend to try and understand the tyres more.
"We have some ideas to be a bit more competitive and we will try. With just two tyres you have to adapt the bike more for the tyres and you have to find the right balance, and that has been an issue for us.
"Honda is struggling a lot with the front because they don’t find the balance. We are better than that but not at 100 per cent.”