Topic: Swapping PD41B carbs for PD42B?

[DHuffman]

Hey guys,
I have a '77 CB750F that came with PD41B carbs on it. Unfortunately, two of the carb bodies are pretty far gone with oxidation, so I'm looking to get a different set for it. A member on here offered me a set of PD42B carbs for a fair price, but I'm concerned about compatibility. I believe PD42B are form a 1978 CB750K? I've heard the only difference is the stock Jet sizes, so would swapping in the '77 F jets into the '78 K carbs work?

Thanks!

[evinrude7]

maybe this will help.  http://forums.sohc4.net/index.php?topic=160707.0  http://forums.sohc4.net/index.php?topic=140427.0

[Airborne 82nd]

I have a 78 750K and use both sets of carbs (just bought one set for a spare) I don't recall but one set has to have shims if you need to tweak them the other set has slots that a little c clip snaps into. Hang on to any of the brass parts from your old set they may come in handy later on.
 This chart will help.
http://www.hondachopper.com/garage/carb_specs/carb_specs.html

[flybox1]

If your bike is stock, and these 42B carbs have stock(for a 78) jetting...just slap them in and go.

[DHuffman]

If your bike is stock, and these 42B carbs have stock(for a 78) jetting...just slap them in and go.

To my knowledge mine were stock. I know the member said he had put new jets and kits on the PD42Bs, I have rebuild kits though, so if he put something other than stock jet sizes (i.e. for pods) then I can use my rebuild kits. 

Thanks for the help everyone!

[flybox1]

IIWM, and the jets in these new carbs didnt have the Keihin logo on them, id replace them.
Cheap carb "kits" are really only good for the soft parts.
Id go thru the carbs once....making sure the accel pump and fast idle cam were functional, and do a quick clear tube test of the fuel levels before putting them on the bike.  There's no telling what the PO changed/adjusted....

[DHuffman]

IIWM, and the jets in these new carbs didnt have the Keihin logo on them, id replace them.
Cheap carb "kits" are really only good for the soft parts.
Id go thru the carbs once....making sure the accel pump and fast idle cam were functional, and do a quick clear tube test of the fuel levels before putting them on the bike.  There's no telling what the PO changed/adjusted....

Couldn't agree more. I have 4 K&L revuild kits (needles, gaskets, etc) carb kits and the 4 Keihin jets out of my PD41B carbs.