Topic: CB550 Carbs - 46A & 46C

[Johnie]

Just picked up this 78 CB550K with PD 46C carbs. Was looking at a 550 carb tutorial on this site which is for the 46A. Is there a difference between the 2 or can I still follow that 46A tutorial by Brian Barnes?

[Bankerdanny]

You can use the 46A tutorial.

[Johnie]

Thanks...this is the first set of PD carbs I will be doing and they look a bit different than the 750's. Is there actually a difference between the A & C designation?

[ekpent]

 How far are you taking them down Johnie ?  Those style of carbs look a lot more complicated then our 750 carbs if you plan on splitting them.

[DaveBarbier]

Harisuluv is probably the one you want to talk to, but I don't think there's any difference aside from jetting changes and float height.

I'm prepared to be schooled.

[DaveBarbier]

Also, there's no real need to break the rack down if cleanliness is your goal.

[Johnie]

Eric...they do appear more complicated than the 750's. Glad I posted as I was going to separate them like I do the 750's.
Dave...can I put the entire rack into my Gunk carb dip minus the floats and not hurt anything? I do have the new OEM o-rings, gaskets and new Honda rubber tipped float needles that came with the bike still in the package. The slides move free and the carbs were gas free when I got the bike. I see on this set the slow jets are pressed in compared to the 750's. Inside the slide area there is some dust as the PO had the carbs off and sitting on the floor in the garage.

[brewsky]

The problem with NOT taking them apart is you can't replace the o rings in the fuel supply tubes between the carbs if you don't, and they can (will eventually) leak.

Plus, you will not get the satisfaction of solving the puzzle of how to put them back together!

[Scott S]

The float height settings are different and one is preferred, no matter which carbs you have. But I can't remember off the top of my head which one.....17mm, I think?

[ekpent]

 Just me but I would keep the rack together, do a cosmetic clean on the outside, clean all the removed jets and prove the passages with some spray cleaner and air, set floats,assemble and hook the rack up to a remote gas tank to check for leaks and if all good mount them up. They look pretty darn clean inside with no varnish etc.

[DaveBarbier]

I can't say whether or not it would be safe for the remaining o-rings if you submerged them in some parts cleaner.

Get a pair of parallel jaw pliers and pull the slow jets out. Maybe a little heat and PB Blaster is needed, but they can come out fairly easily. Or maybe regular pliers would work but I like getting a good grip with the parallel jaws with a strip of thin leather so you don't maul the jet. Pull straight out and twist a bit back and forth.

[DaveBarbier]

Just me but I would keep the rack together, do a cosmetic clean on the outside, clean all the removed jets and prove the passages with some spray cleaner and air, set floats,assemble and hook the rack up to a remote gas tank to check for leaks and if all good mount them up. They look pretty darn clean inside with no varnish etc.

+1

But as you have the remote tank on it I'd verify the fuel height with the clear tube method.

[brewsky]

Another slow jet removal technique....cut short piece of re-inforced fuel line and slip over jet, grab with vice grips and , as stated above, pull straight out, twist if you must, but try to avoid rocking

[Bankerdanny]

When I did the PD's on my '77 550K I didn't have any issue separating them. The only issue with dunking the carbs is the same as most SOHC carbs: make sure you take out the felt o-rings or you will ruin them. I used a can of Berryman's on mine with no harm done.