(CB550) 022A vs PD46 carburetors... thoughts?

jammer415

Been Around the Block
Wondering what the consensus is on the PD46 carburetors that came on the 77-78 CB550 vs. the O22A carbs that came on the earlier models.

I’ve read mixed feedback... Some say that the newer design PD46 are more difficult to tune/sync? Some say that the O22A are more problematic.

What do you guys think?
 
in my personal experience with over two dozen of each version under my belt.....the PD46 are far easier to tune when screwing around with aftermarket exhaust and pods. The only troublesome part on the PD46 is the press-in style pilot jets but I modified a spring-loaded centerpunch tool to make install of those a breeze....to remove I grab them with a pair of sidecutters and pry against the main jet post.

The 022A are a simpler carb and easier to troubleshoot on an otherwise stock bike.

basically I prefer the 022A for a stock app and the PD46 for modding.
 
focusinprogress said:
in my personal experience with over two dozen of each version under my belt.....the PD46 are far easier to tune when screwing around with aftermarket exhaust and pods. The only troublesome part on the PD46 is the press-in style pilot jets but I modified a spring-loaded centerpunch tool to make install of those a breeze....to remove I grab them with a pair of sidecutters and pry against the main jet post.

The 022A are a simpler carb and easier to troubleshoot on an otherwise stock bike.

basically I prefer the 022A for a stock app and the PD46 for modding.


Wow! Ok that is super insightful. Since I don’t have the heart to cut apart a vintage stock bike in good condition, I’m looking for one that I’ll need to bring back to life... and turn it into a cafe/brat bike.

Based on your feedback, since I’ll be removing the airbox and installing custom exhaust, I’d be better off with the PD46?

Are those press/in jets easy to find online?
 
Also, I know velocity stacks may be better for the stock carbs (with custom exhaust and missing airbox), since the air coming in won’t be as turbulent with v-stacks as with pod filters attached directly to the carbs like so many people run (air is meant to be smooth via the airbox).

I couldn’t find any CB550 Mikuni kits like there are for the twin cylinder bikes... Is there a typical go-to aftermarket brand or set up that is ideal for the CB550?

Would Mikuni carbs work on the CB550? If so, which size?
 
if you mean the real fancy $1500+ type mikuni carbs, they don't make any small enough for a cb750 let alone a 550.

Keihin makes the CR "special" carbs and a lot of guys spend big money running them but I really don't like their street manners at all, they're just slide carbs with no accel pump and they are like an on/off switch so their kind of aggravating to street ride on for me.

The PD's are your best bet.....if you really want mikuni's you'd have to measure the spacing and see if some older suzuki/kawasaki 4cylinder carbs would fit, something off maybe an early GS or KZ before they went to constant velocity carbs.....but all this just to have mikuni instead of keihin you're just setting yourself up for a ton of aggravation figuring out what jets and needles and needle clip position to run on carbs meant for a totally different bike.

Look into Steel Dragon for velocity stacks if that's the route you want to go. 77-78 cb550 would be what fits the PD carbs. Otherwise, UNI brand pod filters are the best pods.....but even better would be like a cognito airbox (looks like the old breadbox style performance filters but WAY updated) or fab something up similar. Wouldn't be too bad to fab one if you're any good with sheetmetal and a drill press....could even re-use the boots from the stock airbox. Actually, that brings up another possibility.....some people take off the actually filter housing from the stock airbox setup and just mount an adapter on the back of the 4-1 plastic intake plenum and toss a clamp-on cone type filter there.....seems to work quite well also.
 
Wow thanks. A lot of really good info.

Regarding airbox vs pods... On my CL175, I installed 3” aluminum pipes to the carbs by sliding them inside an exact fit vinyl coupler tube, and attaching pods at the ends with hose clamps, which seemed to really stabilize the flow.

It never made sense to me to put pods directly on carbs, the air coming seems like it would be so turbulent and effect performance.

The airbox customization sounds like a great idea and will definitely look into that.

I’m looking for a 550F as my next bike... I just passed up a super clean 77 because it had 087A carbs on it (which are from 76) and a motor from an “earlier model”.
 
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