Yes,they are part of the breather system and need all the crap cleaning out.Just been finishing off doing the same thing on project CDX. ended up getting a shallow tray filled with petrol and leaving the breather bridge in there to soak.Then blew down the pipes,stuck a length of small bore plastic pipe down there and wiggled it about,soaked it again,blew down it again...........
Couldnt believe the amount of shite that came out considering I had already cleaned them in the usual way a couple of days ago.The petrol ended up a darkish brown colour with lots of lumpy bits in.Now tipped it out of the tray and theres a thick layer of sediment in the bottom of the tray.
Spend a bit of time on it Webby,you may be surprised at the amount of crud which comes out,depending on how well it has or hasnt benn done in the past.
If everything is really scummy I would recommend using petrol initially to shift the worst of it before wasting lots of cans of carb cleaner.
