HRC vice president Shuhei Nakamoto has explained Honda's continued opposition to a control ECU being made compulsory in MotoGP.

New rules mean that Magneti Marelli-built ECU hardware will be used throughout the MotoGP grid in 2014.

However the Factory class will continue to use its own bespoke software, in return for less fuel, engine changes and a freeze on engine development relative to the Open category.

The current format is set to continue until at least 2016, although many believe the control ECU hardware and software will eventually be made mandatory for all, with Dorna CEO Carmelo Ezpeleta among its supporters. Controlling ECU software would allow for restrictions on electronic rider aids.

But Honda, reigning world champions with Marc Marquez, has repeatedly warned that removing the chance to develop its software would cause them to leave the sport. Speaking at last week's opening 2014 test session at Sepang in Malaysia, Nakamoto explained:

"If MotoGP was all Open class machines? This is Carmelo's idea. Honda's position is clear. Honda is here [because] we are interested to develop the machine. If we cannot develop the machine here, we lose our opportunity to continue racing.

"This is the Honda board members' opinion. Not myself. If all the regulations say, 'You cannot develop software, everything is fixed'. Immediately Honda stop racing."

But in order to reduce costs and limit machine performance, MotoGP has already tightened technical regulations in areas such as engine durability - only five engines per season are allowed for the Factory class - and fuel limits.

Nakamoto insisted that agreeing to such regulations was very different to a potential ban on ECU software, since Honda could still achieve valuable R&D for its road machines.

"Years ago, racing engine designers just concentrated to make a big [powerful] engine. Now the engineer has to keep performance whilst making a long life engine. We found some interesting technology and technical material from this. This is quite useful for the future.

"We will find more with the change from 21 to 20 litres of race fuel for this year. With 24 litres [the Open class limit] we cannot find anything. But 20 litres, five engines and software [development] are all important areas for the motorcycles of the future."

While Yamaha has supported Honda's opinion, albeit without the threat to leave, Ducati is pondering a 'rebellion' in the form of a switch from the Factory to Open class - in order to avoid the new engine development freeze.

The freeze means all five engines used by each rider during the season must be of an identical specification, which would hurt Ducati's ability to make sweeping changes to the struggling Desmosedici.

Asked if he thought the engine freeze clashed with the philosophy of machine development, Nakamoto insisted: "We can still develop the engine for [the] next year."

One technical challenge Nakamoto hasn't been impressed by was the need to transfer and adapt Honda's previous ECU software from its own in-house electronics system, to the new standard ECU hardware.

"It's like changing from a Mac to Windows computer. We change from Honda ECU to Magneti Marelli. The total cost is huge. We also had to buy the data analysis system from Magneti Marelli. The cost is unbelievable.

"Last year's Honda [ECU] was smaller, cheaper, more capacity! The Magneti Marelli hardware is 50 percent more expensive than Honda's one. So expensive. Hardware, data analysis, software. Unbelievable."

Technical issues aside, 2014 marks the end of rider contracts for all of the official manufacturer riders, barring Ducati's Cal Crutchlow.

Repsol Honda would doubtless like to keep record-breaking rookie champion Marquez, with team manager Livio Suppo also speaking highly of team-mate Dani Pedrosa.

But Honda will also once again talk with leading rival Jorge Lorenzo.

"Honda never have a number one and number two rider. Both equal. Of course we are interested in Jorge because he is one of the top riders. This is normal," said Nakamoto. "At least we like to talk."

Suppo added: "Of course we understand Marc's value. He is very young and of course will hopefully remain with Honda in the future because he is a very strong rider. But don't forget about Dani.

"Dani as well was very close to the championship, almost every year since 2006. Many people forget about Dani. All top riders are ending their contract and it is normal to speak to everybody. At the moment it too early to speak about it but I can say Honda is happy with both our riders."

Marquez was fastest throughout all three days of the opening Sepang test. The return visit takes place from February 26-28.