McWilliams impressed with V5, wants two-stroke.

Team Proton KR riders Jeremy McWilliams and Nobu Aoki were back on the radical new 990cc four-stroke KR V5 at the sweeping Brno circuit, and enjoying a package of minor but significant revisions that have addressed teething troubles found in the bike's first few races, as well as unleashing more of the potential horsepower of the new machine.

Changes include reworked crankshaft design and construction, to improve strength and endurance of that crucial component; as well as revisions to engine breathing that have increased the power output somewhat. But the bike is still in its infancy, and still in first prototype form - this tenth round of the season is only the machine's fifth GP, after it was brought out for shake-down tests at the French GP, with the season already well under way.

McWilliams was happy with the improvement, but had mixed feelings. He knew he could be faster at this technical circuit on the old 2002 500cc two-stroke, but at the same time is dedicated to pushing the new project forward, even at the cost of short-term race results.

He was frustrated also by just missing the chance for one last fast lap on qualifying tyres, after crossing the start line just seconds after the chequered flag was displayed, denying him the chance of one more lap.

"I missed my chance at the end, when we took a little bit too long to get a qualifying tyre on. I could have gone a little bit faster. But the times show that we have definitely improved. In tests here a few weeks ago we were doing 2'03s. I thought we would be a second quicker, so I am pretty happy to be in the 2'01s," he explained. "The bike feels much the same as before at the top end, but it's definitely better mid-corner and on the exit. I'm struggling a bit with suspension settings, but I hope that can be fixed just with spring changes, pivot position and oil levels. I know I could get below 2'00 on the two-stroke, and I will probably ask if I can ride it. But that wouldn't really help us in the big picture."

Aoki also appreciated the power boost, but was struggling today with rear tyre grip on the way into corners, which hurt his lap time.

"The engine has got a little better in the summer break, but I'm having a big struggle with rear grip under hard braking," said the Japanese. "I'm going into all the corners sideways, which is not so good. It's a matter of engine braking, but I think the slipper clutch is working okay, and that it will have to be solved with engine management in the long term. For tomorrow we will try changing the weight distribution, with a higher front ride height to put more weight on the rear."

"We're not as far off as we were, though we'll have to wait until Sunday to see how far we've really progressed. Today went good, and I'm pleased we've made a step forward," said team manager Kenny Roberts.