This problem seems peculiar to the Aluminium chassis Plus 8, it's really is frustrating. Mine was sorted at the Factory under warranty and has been fine since but, sorry I don't know the cure. As I said previously I can't understand why the 'fix' hasn't been released to the dealers. It's a case of rerouting or modifying pipes and less than a 2 hour job. Aero owners complain of a similar problem but it's nowhere as bad as the Plus 8. My S1 suffers from it to a lesser extent but holding the nozzle at 12 o'clock seems to solve it.
