On the cover of the Haynes manual for the 850 is a photo of an 855 with most of the bonnet 'erased' to reveal the engine. High on the metal screen shrouding the firewall, a bit on the driver's side of centre, is a black, oval-shaped 'thing'. It looks like it's maybe 4 or 5 inches long, mounted horizontally.
What is it?
I might have missed something, but I've gone through the manual from cover to cover and I can't find any reference to this part.
cheers,
Henry