Black day for Marlboro Yamaha.

Marlboro Yamaha Team riders Carlos Checa and Max Biaggi failed to make the finish in Sunday's Marlboro Spanish Grand Prix, Checa exiting the race with bike problems while Biaggi was black flagged after failing to see the signal informing him of a stop-and-go penalty imposed for jumping the start.

Both men had qualified on the second row of the grid and Checa showing great promise in morning warm-up when he was fourth quickest. He ran strong in the race as well, holding a good sixth place until his YZR-M1 stopped just six corners from the chequered flag.

"It would seem we were out of luck today," said Marlboro Yamaha Team director Davide Brivio. "The race direction said they saw Max jump the start and we're not contesting that but the stop-and-go sign wasn't clearly displayed. We also put 'IN' on his pitboard but in the melee of the first few laps riders don't generally look at their boards. We've been to race direction to alert them to these facts and they agreed that the sign was not visible enough.

"No further action will be taken against Max but, sadly, there's nothing more we can do now. I feel so sorry for him and also for Carlos. He rode a great race, riding 100 per cent every lap, and it was bad luck that the bike should stop on the final lap. We've discovered that it was a failure with a small electrical component that caused the problem and we shall make sure it can't happen again."

Carlos Checa rode his heart out this afternoon only to suffer heartbreaking luck on the final lap when his Marlboro Yamaha Team YZR-M1 stopped, losing him a certain sixth-place finish and a valuable ten World Championship points. The Spanish favourite accepted his fate with typical grace, turning his attention to the team's two-day test at Mugello, Italy, later this week.

"The bike just stopped and I don't know why," said Checa who had qualified fifth fastest, just a fraction off the front row. "That's life but maybe it's better to stop on the last lap when you're sixth than when you're first! Now we have to look towards our next tests and the next race. It was a pity because I think we did a really good job this weekend. I was feeling good on the bike as the race went on. In the early laps I had some front-end push, so I wasn't able to brake and flick with confidence. But as the rear grip and the fuel load went down a little there was less front-end push, so I felt more comfortable. Now we must go testing at Mugello and keep working."

Max Biaggi was excluded from today's race for jumping the start and then failing to see the rather small signal board requiring him to come into the pits for a stop-and-go penalty. Riders are allowed three laps in which to react to the signal but since this happened in the early laps when riders are far too busy to look at their own pitboards, let alone at another board in a different location, he failed to respond and was then black flagged.

"The bike moved maybe 20 centimetres over my starting marker, so I braked and put my foot down, so I didn't gain any advantage," said the Italian who was starting from seventh on the grid. "If the race direction think that I'd jumped the start, fair enough. The problem was that the stop-and-go board was surrounded by many other boards so I didn't even see it. When the black flag was displayed the officials were on the track, so it was easy to see and I stopped immediately. I think everyone would agree we had some real bad luck here; it's been a bad start to the season."

French Yamaha rider Olivier Jacque, who was penalised after Biaggi also for a jump-start, confirmed that he did not see the official board either and only stopped because of his pit-board.