There was a change to the operation of the EVO Power Valve. Originally it worked on Vacuum, but Rotax ‘upgraded’ it later to work on pressure. They supplied an upgrade kit to change this which included a ‘T’ connector instead of a ‘Y’ connector for below the fuel pump, a rubber isolator to mount the solenoid, a new green spring (to go between the Bellows and the Power Valve cap) and some black tubing. The diagram you have above shows the upgraded option. If you had the original Vacuum set-up you will also need to remove a spring that is inside the bellows, alter your plumbing as per the above diagram and turn the green plastic one way valve around.