They all smoke a bit, not a problem unless there's a lot more smoke than normal. This is the engine blow-by, basically all the combustion gases that get past the piston rings. Plus smoke just from hot oil, any boiling-off water condensate that's formed inside the engine, and anything that gets past the exhaust valve guides but that should be pretty minimal. If a compression test looks OK I would ignore it. Low compression suggests a cylinder overhaul may be wanted.
Usually Honda connected this pipe to the air cleaner box via an oil separator, just a sort of sponge pad you would clean occasionally. Putting pods on or some other airbox mods leaves it hanging open, whereupon you see the smoke. You can get mini-pod filters that soak up the oil but there's still some smoke visible with a hot engine.
