Honda CB 550: Complete Carb Rebuild Part 1

My first workbench…

The very first thing I did when I got my Honda CB 550 was pull the carbs off, and clean them.  Everything I had read led me to believe that there is no way to diagnose your bike, or any potential problems with it, unless the carbs are in a good place.  The cost of having a mechanic do this for you is astronomical.  And since I had planned on doing all repairs myself, I figured i would get right to it. 

At the time, I was wrenching on the curb, and the only place I had to clean them was at my desk, on the 4th floor.  The smell of gas was going to be overwhelming, so I ended up disassembling them at the desk, and then letting them soak on the fire escape.  For those of you who have been inside a set of carbs, you know how many small pieces there are, and dropping one from the 4th floor would have really been a bummer.  Luckily, I managed to get them apart, cleaned and back together again, without any major mishaps.

The problem was, there was some damage to one carb body.  One of the forged tubes holding the main jet was worn down about 3mm-4mm.   Nothing I could do about that.  I proceeded to assemble all the parts, hoping the jet would stay in place from the pressure from its o-ring.  Fortunately, it has run pretty well ever since.  The damage was minor, but it ate at me every time there was the slightest problem.  How was I to know if the shaky idle was caused by the damaged carb?  All cylinders not firing evenly?  Must be that carb!  The only remedy was to get a new set of carbs, so I could set my mind at ease.

The motorcycle I have, the CB550K, is part of one of the most popular series of bikes ever produced.  Unfortunately, due to concerns over EPA regulations, my particular model (1976) is the only one made with these specific carbs.  Well, after looking for one year, I finally found them.  Although the condition was said to be from a running bike, when they arrived, they left a little to be desired.  They were ‘mostly’ complete, and with the other set of completely corroded carbs I had previously bought, I would be able to Frankenstein a rack of good, healthy carbs, once and for all.

So I began the tear down.  I hoped that the cleaning I had done a year before would stay fresh in my mind, but with the amount of work I have done to this bike, those memories had faded.  It seemed all new.  To complicate matters, I needed to take the 4 individual carbs apart from the main rack, so that i could replace the missing parts.  This was all new, and proved to add time and effort to the task.

Here Goes:

The first step is to make sure you set yourself up with a nice, clean table to do the work at.  The workbench at Moto Preserve proved to be righteous, compared to the desk in my apartment.  Also, make sure you have several containers.  Many people use zip lock bags, but I have saved up humus containers for a while, for just this type of occasion.  Have a sharpie ready to label all the containers.

So I commenced removing the carbs from the rack.  Careful to take photos of each step, so that I can reference them when I start to reassemble.  Make sure to not only take close up shots, but ones that have a wide enough angle, to portray the way parts interact with one another.  This comes in handy when you can’t remember which direction certain parts fit together.

I took my time, and made sure each part went into the container designated for that particular carb.  Things started piling up, as I separated each movable part, and I was getting closer to my goal of having them completely apart.  Next up, to use the carb dip, a highly toxic formula of cleaner, that is specifically made for these parts.

Stay tuned for good times with chemical resistant gloves!…

2 Replies to “Honda CB 550: Complete Carb Rebuild Part 1”

  1. pleaseeeeee help. need to clean out the shmutz on the left side carb. if theres an easy way to do it pleaseeeeeee help me. i have no access to a professional

    1. Hey! Not sure if you would consider cleaning carbs easy or not. It’s not overly difficult, but it’s sorta a pain in the ass.

      Can you describe the “schmutz” that is causing you concern?

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