British MotoGP rider James Ellison has been rocked by news of development delays to his WCM machine just two days before the season-opening Spanish Grand Prix in Jerez.

The 24-year-old from Kendal was already resigned to starting Sunday's race aboard a four-cylinder machine but had been promised a V6 replacement would be available in time for the Italian GP at Mugello in June.

But now Czech engine manufacturer Blata have revealed the new power unit will not be ready until the Czech Republic Grand Prix at Brno in late August.

And company director Pavel Blata said: "This represents a considerable delay from our earlier hopes but we've realised that bowing to the pressures of having the engine ready for the opening rounds of the season makes no sense in the longer run.

"We've made a long-term commitment to race in MotoGP with WCM. They understand we have to do things the right way and know it'll pay off for all of us.

"We will support their continued use of the current four-cylinder machine until the six is ready."

And Blata's decision has received the backing of WCM director of racing Peter Clifford who said: "It makes absolute sense.

"There's simply no point in forcing the bike onto the track just so we can use it at this end of the season.

"We're much more interested in the quality of machine we will be using at the other end of the season."

Other British interest in the MotoGP resides in Proton-KR rider Shane Byrne and Anglo-American John Hopkins, who will represent the factory Suzuki stable.

But while Ellison's preparations have been beset by difficulties, privateer 250cc rider Chaz Davies - Britain's sole representative in the 250cc world championship - is confident technical improvements will boost his chances of success at the 2.7-mile Circuito Permanente de Velocidad.

The 18-year-old Davies, who hails from Wales, has seen his Aprilia Germany ride fitted with a new chassis which had been updated from a 1998 to a 2003 model.

"The new chassis is definitely the biggest difference with the bike," Davies confirmed.

"It's not as good as the factory guys', because it's not a 2005 model but it's better than what we had last year.

"It's a lot more stable through the corners and it means I don't have to work as hard to turn it.

"The engine is still some way down on power compared to the factory bikes but as far as last season is concerned, we seem to have improvements in every area and I'm really happy about that.

"The best thing about it is that we haven't had to sit down with the team and start wracking our brains trying to think of solutions - everything's come very naturally so far.

"My goal this year is to be the best privateer and I reckon Sylvain Guintoli is going to be my closest rival in that respect.

"I know it's very early days but I'm pleased with the progress we've made already."