Hayden not downcast despite problems

The world champion fell and slightly injured his hand during the morning, then had a string of electrical problems at the start of the afternoon session.

Then in the closing moments of practice Hayden suffered a massive engine blow-up that scattered parts of piston and valve across the track.

Honda have been under pressure from the riders to provide more power, the works team having failed to win a race since Laguna Seca last season.

"Sure, it's frustrating," said Hayden. "You don't expect engine problems. You don't expect HRC to be having these kind of problems at this point in the season, but I learnt long ago not to give up.

"The same reason I didn't give up after Portugal last year or after anything else.

"Friday the 13th hasn't been good for us. It let go big. Something nasty happened. I didn't want to just dart to the inside in case someone was alongside me."

Hayden stressed that there were no new components on the engine this weekend, and nor had additional revs been made available, although his teammate Dani Pedrosa was running the latest in a succession of new exhaust designs.

After a difficult start to 2007 that saw him struggling to acclimatise to the 800cc Honda, Hayden has taken a step forward in recent races and scored the first podium of his title defence at Assen a fortnight ago.