Pata Honda's Jonathan Rea was left feeling frustrated as he struggled with a new electronics package on his CBR1000RR Fireblade during tests at Jerez.

The electronics system used by Rea and teammate Leon Haslam is being developed by HRC in MotoGP.

The Ulsterman managed the fifth fastest time, 0.883s behind pacesetter Marco Melandri on the Goldbet BMW in Spain, but Rea concedes his team has plenty of work to do at the final shakedown at Phillip Island in Australia prior to the opening round of the 2013 world championship there on February 24.

"We're not really where we want to be right now because we couldn't get as much out of these two days as we would have liked," he said.

"Some things just can't be fixed on site and the electronics problem we had was one of those.

"The system was taking too much power away so we really needed more track time to sort that out.

"However, I felt some good things, like it's catching slides a lot more safely now, so that's encouraging," added Rea.

"It's been a frustrating test and shown us that we need more track time before the first round, but that's coming in Australia, so we'll hope for better luck there."

Haslam was eighth quickest, 1.8s down on Melandri.

The pair also tested a heavily revised swingarm and new Termignoni exhaust system at Jerez.