If Aleix Espargaro and Yamaha provided the positive Open class headlines with a shock fourth place at the Sepang MotoGP test, the disappointment was the Honda RCV1000R Production racer.

Although second to Espargaro in the new class, former world champion Nicky Hayden was just 13th overall. Hayden's best lap was 1.5s behind the Spaniard and two-seconds from Factory Honda test leader Marc Marquez.

A lack of engine performance was Hayden's biggest concern. "It was pretty demoralising when I tried to follow other guys," said the usually upbeat American.

HRC vice president Shuhei Nakamoto stressed that there was a very different philosophy behind the Yamaha and Honda Open machines.

"I don't know the detail but it looks like Yamaha's Open class machine is last year's Factory machine. This is allowed," said Nakamoto.

"Our approach is different. We made a machine to sell. If the team use it for two years. In the first year they pay 1.2 million euro, then next year they just [pay for an upgrade package]. If you divide the cost by two years it is less than one million euros a year. They also still own the machine and can sell it, with some value.

"To make a machine for less than 1.2 million euro, Honda has to use a standard valve spring system, standard transmission and a little bit different specification of Ohlins suspension. But main parts - chassis, swingarm, bodywork is factory specification."

In a nutshell, it seems that the Honda RCV1000R would have been eligible for the former CRT rules, where machinery could potentially be claimed, effectively limiting the level of technology due to confidentially concerns.

The fact the Honda is offered for sale - and can be sold on - suggests the company would have tolerated the RCV1000R being part of a claiming rule system.

That would not have been the case for the Yamaha (and Ducati) Open class engines.

The removal of the claiming rule has allowed Yamaha to lease full-specification YZR-M1 powerplants, including pneumatic valves. In order to help the new Forward Racing project, Yamaha is also supplying the chassis and swing-arm while the bike has 'Factory Ohlins' suspension.

To be eligible for the Open class - and all its benefits in terms of race fuel, engine changes and engine development - teams are simply required to fit the full control ECU system. That is essentially what Ducati has done for Yonny Hernandez's Open machine.

Nakamoto confirmed that if Honda was to offer last year's Factory class bikes with the control ECU software, it could only be "for a lease system because of confidentiality. We cannot sell the Factory machine."

Amazing, and probably tongue in cheek, Nakamoto even suggested Honda had misread or misinterpreted the rules.

"Our [Yamaha and Honda] philosophies are different. We thought, maybe Honda did a misunderstanding, Open class category you have to sell [the bike] to the team. I read the regulation book again and there is no mention you have to sell..."

He added: "Last year's regulation for CRT the performance gap was too big. Then Honda decided to make a reasonably competitive machine. It would have been easier to lease last year's factory machines, because we don't need to develop a new bike, just fix the single [ECU] software which is much easier than a completely different machine.

"But this was Honda's approach: Production and Factory bikes. Production means Honda will sell.

"We will never stop machine development. Engine and chassis," he continued. "The teams will not pay more for things like better performance pistons, we would just fit them for the next engine change. But if they want a new chassis or something we will ask them to pay."

Nakamoto ruled out the ultra-secretive seamless shift gearbox finding its way onto the Production Racer, but left the door open for higher-revving pneumatic valve technology.

"Seamless transmission no, zero per cent [chance]. Pneumatic valve we may be able to do something. But the cost difference is big so we would need to ask the teams," he said. "To put the pneumatic valve on the engine looks very similar but the chassis side is very different, because of the air [source]. The parts have to change a lot."

Official top speed figures were not available at Sepang, but Hayden said that new Honda was "a couple of k [km/h]" faster than the Aprilia CRT class bike raced by Aspar last season.

The top Aspar speed during last October's Malaysian Grand Prix was 309.9km/h, which was 17.6km/h slower Marquez's factory Honda at that event.

Hayden highlighted both acceleration and top speed as needing a significant boost, but Nakamoto claimed the difference in performance is only in the higher gears.

"We checked the data. Acceleration is not such a big difference. Because acceleration limitation is tyre grip," he said. "For top power Factory [bike] is better, but middle and bottom range the difference is very small. The Factory machine power has to be reduced for first, second and third gear. So there is no difference until fourth, fifth and sixth gear.

"We checked the data and the time difference here between Factory and Production machine [with Honda test riders on the straight] was 0.16s. So on the two straights it is 0.3s a lap difference from the engine. The engine cannot make two or three seconds a lap.

"The lap time difference is big, about 1.5s slower than Aleix, but to be honest Honda's machines are not easy to ride.

"We believe it will be closer when the riders understand the machine. Before this [official] test, we did a private test here and the lap time difference [with Honda test riders] was less than one second."

Hayden is one of four riders using the RCV1000R this season. Team-mate Hiroshi Aoyama was 16th overall (+2.850s), Gresini rookie Scott Redding 21st (+3.300s) and Cardion AB's injured Karel Abraham 26th (+5.728s) out of the 27 riders to post a Sepang lap.

The second Sepang test will take place at the end of this month.