Topic: Carb ID help needed

[db22]

My bike is a 1975 CB500K, rescued from the back of a friend's garage.  It most probably was assembled from several bikes -- the carbs are not correct for 1975, as far as I can tell. 
I know these are PD carbs, but I can't identify them exactly.  Being a complete noob, I'm not sure if the jet in the middle is the main or slow jet (the exploded view in the Clymer book leads me to believe it is the main).  When removed, a needle is visible that moves up and down when the throttle is moved. 
In the first picture, the jet removed from the middle of the carb has a perforated tube attached.  Is this the "emulsifier tube" I have heard others mention?  Is it permanently attached, or just stuck due to the age of the parts?

[dave500]

its just stuck it will unscrew.

[TwoTired]

Under the PD marking is a flat where it should be stamped 46A or 46C.
The main jet is in the center where the slide needle is.  The jet screws into the emulsion tube which also acts as the main jet holder.
The slow or more correctly the the pilot jet is between that main jet and the Idle Mixture Screw and pressed into the carb body.  If you are cleaning, you should yank that out and clean till you see light pass through it.  Then tap it back in after ensuring the passageways in the body are clear.

Don't use the Clymer for these carbs.  They will just confuse you.  Get the Honda shop manual supplements (which are higher chapter numbers).

Cheers,

[db22]

Thanks, TT & dave500!