Repsol Honda's Nicky Hayden will continue to test the pneumatic-valved RC212V at Catalunya today - and has said the team may well try it in a new chassis.
Hayden spent most of yesterday evaluating both engines and the American said he was was happy with the pneumatic-valve engine's top speed and rideability and spent most of his time working on set-up with that engine. Today he will focus on race-distance tyre testing with the same engine.
He said: "We tried the new bike, my feeling with it was good, it had some good points. But we need more time to check the bike in a long distance situation. We tried some general setting things with it, and we only using race tyres, seeing what kind of endurance we could get because we had some problems with set-up during the weekend wearing the tyres more than we liked. We'll run with it more tomorrow and maybe try a new chassis."
Team-mate Dani Pedrosa crashed yesterday afternoon and has bruised his back. After a trip to hospital, he has been told to rest for 48 hours.