Ducati runs engine-braking system, Checa falls.

Ducati Marlboro riders Loris Capirossi and Carlos Checa used today's opening two practice sessions for Sunday's Spanish GP to continue development work on Ducati's innovative new engine-braking system.

After initial tests last month, both riders had both their bikes fitted with the new unit for the first time, illustrating the factory's confidence in this new technology which initially appeared to be greeted with 'caution' when first tested by the riders.

The new system is designed to optimise braking stability by reducing excessive engine-braking forces, and has the added advantage of slightly reducing fuel consumption.

"We are using the new system because we know that the best place to really stress new parts is at a race," said Ducati Corse director Filippo Preziosi. "During testing you can ride many laps without problems, but it is under pressure in a race situation that you find new limits, which gives us better information to improve.

"Today is the first time that we have focused 100 per cent on the new system. After just two hours of track time we're very happy with progress. We have already matched our best time on race tyre from our November tests here and we're not so far from the front guys," added Preziosi. "It's encouraging but we still don't know how long it will take us to find all the benefits of new system, but we are working towards that."

The team's lead rider today was Capirossi, ended the first day of the 2005 MotoGP season in ninth spot, 0.8secs behind Sete Gibernau. The Italian spent much of both free practice sessions working on the new clutch system, which has undergone minor improvements since the team tested here two weeks ago.

"I'm still getting used to the system - it feels very different to ride with, like you've switched off the engine when you brake," said Loris. "But it already has its good points and I believe it will give us a real advantage by improving stability during heavy braking, that's why we're sticking with it.

"At the moment the new system isn't quite as the same level of the standard system but it gets better every session," he revealed. "We had some trouble this morning but made a big improvement this afternoon."

Team-mate Checa slid off during this afternoon's practice session, thankfully not aggravating the shoulder injury he sustained when he tumbled at Catalunya last month. The Spaniard is having to play catch up here because he missed last month's group Jerez tests, following that fall at Catalunya.

"It wasn't a big crash," said the new Ducati rider, so far just 16th fastest. "I went down at the hairpin at the end of the back straight, just before the gravel trap. My shoulder is probably about 80 per cent at the moment, but I thought it might be even worse before I got here.

"I have a lot to do here because I missed the tests - I'm getting my feeling back after a few weeks off, as well as working on set-up and the new clutch. I've had better days but I'm confident we will improve tomorrow," he added.