From MotoGP.com files

A very different version of the Kawasaki 800cc Ninja ZX-RR was seen on the last day of MotoGP testing at the Sepang circuit in Malaysia.

Kawasaki test rider, Tamaki Serizawa, headed out for his first run of the day may have looked identical to those of his fellow Kawasaki pilots, the high-pitched exhaust note as he accelerated down pit lane was a clear indication to everyone that looks can be deceptive.

By the time the Japanese rider crossed the start finish line at the end of his out lap, the pit wall was lined with people keen to discover for themselves what the strange noise was. Soon they realised that that new engine was a "screamer".

Kawasaki's decision to build a screamer engine for evaluation was made after taking a number of important factors into consideration.

"An even firing order offers a number of advantages over a big-bang version of the same engine," says Kaneko. "Peak power is better, and the even firing order means that the engine is not stressed as hard at high revs. Of course, there are disadvantages as well, with the main one being that driveability is more difficult to control when you don't give the rear tire time to recover between power pulses."

"But in the past year we've seen a reduction in capacity from 990cc to 800cc, which has also meant a reduction in outright power. We've also seen improvements in tire technology, and taming the power delivery has become easier through the use of more refined electronic systems on the bike. These factors mean that it is now feasible to extract the advantages from a screamer engine, such as the increased power, while overcoming the disadvantages through tires and electronics."

Testing is due to continue during the upcoming months on that new engine but Kawasaki is still a long way out before that technology can be use in competition.