Big bugger from Yamaha
Just found this on IBI website.
On the 2-stroke side the HPDI 300 builds on the HPDI 250 which was launched last year. The 3.4ltr V6 unit has a six-throttle format with each cylinder controlled by an individual throttle valve, to ensure, Yamaha claims, superior airflow and better throttle response. The ECM controls ignition and injection timing, while the water-cooled crankcase provides better control over engine operating temperature, increasing performance and reliability.
"The Z300 was the logical next step," said Niewenhuis, who emphasised Yamaha's commitment to a two-pronged 2-stroke and 4-stroke development programme. "We are committed to having two technologies. We want to give the customer the choice."
Yamaha's 2-stroke HPDI line now comprises the 150, 175, 200, 250 and 300.