Mondello twists prepare Team KR for Estoril.

Proton Team KR have been busy testing their newly born four-stroke prototype during the two weekend break since Brno, taking the V5 to Mondello Park in Ireland where they ran the latest power and engine braking improvements.

Although the engine is still in a relatively low state of tune compared, the extra horsepower will no doubt help in the run down Estoril's long straight this weekend, while the engine braking control is at least as important, taking care of the crucial corner entry phase that had troubled both riders.

Team Owner Kenny Roberts was clear: "It will be better at Estoril. We found a decent direction at the last race at Czecho, but it was a bit of a disappointment because the primary gear broke on the best engine.

"Since then we've tested in Ireland, and made a lot more progress with rideability, and with the engine braking programme. Both riders liked the new spec, which makes it easier to get the bike turned. The aim for Portugal is to have four machines with that latest spec," said Roberts.

"We're not developing for speed yet - we've been still solving problems, and the racing gets in the way of development," he continued. "But we probably have 20 more horsepower now than when we started, with just fine tuning. We're not where we wanted to be by now, but we're getting there."

Riders Jeremy McWilliams and Nobuatsu Aoki both welcomed the Mondello test - the Ulsterman returning to a track he used to ride on as a kid, while Aoki was reminded of the pocket bike circuits so popular in his Japanese homeland.

"I've been chilling at home with the family ready for the most hectic part of the season," said McWilliams before talking of the progress made: "We chose (to test at) Mondello because it has plenty of slow technical corners like Estoril and we were very pleased with the results. It's a closed circuit that I used to race at as a kid. It's been extended since then, with a lap of 1:40, and is very twisty.

"It was the ideal place to test the new system that stops the rear wheel locking up under braking and it worked really well," he added. "All we need now is that extra horsepower and the guys are working very hard to find just that. We had one new engine at Brno which was producing some extra power and we hope to take four of them to Estoril. It's been a good break but those familiar butterflies will return to my stomach when we drive through the gate into the Estoril paddock."

"I enjoyed some time with Jeremy in Ireland after the tests, and then went to England for a while," began Aoki. "The tests were very important - for the first time I found out how to work with the engine braking system, and Mondello Park was a very good circuit to see how it works ... like a pocket-bike track. I was able to give the engineers a good idea of what I need for my riding style, and how to get the adjustments. I heard we should get more engines with improved horsepower, which will be very welcome. I'm sure we can improve in Portugal."

The Portuguese race closes the main European season, with the next four races all flyaways, spanning Brazil, Japan, Malaysia and Australia, before the series returns to Valencia, Spain, for the final round on November 2.