Marc Marquez says his first MotoGP practice session of the year in Qatar was thwarted by an electronics problem on his Honda.
Marquez finished the session eighth, 0.818 seconds off the pace set by Yamaha's Jorge Lorenzo.
Honda has struggled during pre-season testing following MotoGP's change to a control ECU but Marquez ended the final test on a high, following a late breakthrough.
During Thursday's first practice session for the Qatar Grand Prix, Marquez said a setting change within the package caught Honda out.
"We changed some parameters on the electronics and the effect we expected would be another one, or very small, but it was really big," he said.
"The feeling was much different, so for that reason I couldn't find the way.
"I did two laps, stopped, one lap, stopped, one lap more, because I felt strange on the bike.
"The engine was not consistent, one lap you'd arrive and the engine brake was good, the acceleration was also good, the next lap was completely out.
"It was more that it was not constant, and then you cannot predict what would happen."
Marquez also acknowledged that Honda starts the season without a clear baseline set-up for traction control within the new Magneti Marelli unit.
"We are playing with the torque, with the engine braking, and also with traction control," he said.
"And maybe last year the traction control was more, we had the base and still this year we are trying to find the base.
"We are here with a good base, but it's still not 100 per cent with the electronics side, especially. That's what we must work on.
"Everything is working well, I believe that on Sunday we will have a good package."