Topic: CB550?

[devinferrante]

Hello Everyone -

I recently purchased a CB550 that is in fairly good shape as a side project. I've got a basic understanding of motorcycles. As crazy as this sounds, I cannot say I'm 100% confident in which CB550 model this bike is. I've searched through all of the charts, etc. that would help make this determination. I am leaning toward it being a CB550K but want to be absolutely sure before I start taking apart the carbs and ordering filters. The VIN does not have an "F" which I believe is what distinguishes the models for the most part. However, the air filter box noted CB550-F. The bike has a 4 in 1 exhaust system - can that be on both models? I am looking to upgrade the air filter first which is why the box noting "F" threw me off from my original assumption of it being a CB550K.

If you need other pics, let me know and I can post.

Thank you in advance!

[flybox1]

CB550K.
Post the engine VIN and the born-on date from the VIN tag, and we can get more info for you.

[Duanob]

Welcome!

Go with the VIN number. But from looks it is a 74-76 CB550K. Non OEM exhaust. the OEM 4X4 is becoming really expensive if you can find one new or in good used shape. If the exhaust was changed I wonder if the jetting was changed as well? I believe all 550 filter boxes have an 'F' in the number and BTW all the paper filters are the same anyway. There are a few items that are the same no matter which 550 you have: brake pads and shoes, oil filters, chains and sprockets, points and condensers, tubes and tires, etc, etc.

[Gene]

If I had to guess I'd say a 1975. K1.

[Bankerdanny]

As others have noted, that is likely an early K. The seat, tank, warning lights, kick start lever and peg location all say K bike. I don't think there is a difference in the filter between the F bikes and the 1976 and earlier K's.

[flybox1]

Looks fairly well kept 
Too bad the tach cable is all tied down like that.
The omission of the front fender(and tach cable holder) is the culprit.  (Also causes front end instability when cornering)
Find another way to keep the cable off the front tire, or pretty soon the cable, or sheath, will wear past usable condition, or get a used fender on there.
Side cover emblems are gone.  Unfortunate as those are worth some coin.

[sweatshirtolympics]

Welcome bruv I'm currently rebuilding a k0 and having a blast.

But seriously welcome and enjoy yourself.

But seriously if you don't want that 4 into 1 let me know hemi 

[devinferrante]

Thanks everyone! I've been working on getting to the carbs, hopefully I can get those off this weekend to rebuild. Any tips or comments are appreciated as always!

[devinferrante]

Looks fairly well kept 
Too bad the tach cable is all tied down like that.
The omission of the front fender(and tach cable holder) is the culprit.  (Also causes front end instability when cornering)
Find another way to keep the cable off the front tire, or pretty soon the cable, or sheath, will wear past usable condition, or get a used fender on there.
Side cover emblems are gone.  Unfortunate as those are worth some coin.

Will do - appreciate it!

[Bankerdanny]

Heat. When it comes to the 550 heat is your friend when taking the carbs off and putting them back. I typically use a hair drier to heat up the boots, it makes the rubber more pliable. You can use a heat gun, but be careful not to melt the rubber.

You can recondition the rubber with a mix of water and wintergreen oil. Use the search function at the top of the main screen to search, there are many threads about it.

[flybox1]

Thanks everyone! I've been working on getting to the carbs, hopefully I can get those off this weekend to rebuild. Any tips or comments are appreciated as always!

Its rare that jets need to be replaced.  Just clean them up and reuse....but...If you HAVE to replace them, only use OEM Keihins from a seller like siriusconinc or jetsrus, and then buy the soft parts from places like 4into1, davidsilverspares, etc....
You can spend cheap money on aftermarket kits, but you'll eventually go back to the OEM stuff.
Aftermarket jets are poor quality.  Just trying to save u money and headaches 

[devinferrante]

Thanks everyone! I've been working on getting to the carbs, hopefully I can get those off this weekend to rebuild. Any tips or comments are appreciated as always!

Its rare that jets need to be replaced.  Just clean them up and reuse....but...If you HAVE to replace them, only use OEM Keihins from a seller like siriusconinc or jetsrus, and then buy the soft parts from places like 4into1, davidsilverspares, etc....
You can spend cheap money on aftermarket kits, but you'll eventually go back to the OEM stuff.
Aftermarket jets are poor quality.  Just trying to save u money and headaches 

Any recommendations for a rebuild kit? I was eyeing this one (https://www.amazon.com/Honda-Carb-Rebuild-Repair-Kits/dp/B006ID2NNU) purely because it had more than one review for a cb550k with great results. I've been told to avoid Keyser.

[JBMorse]

Since the brass parts are generally ok to clean and reuse, what I did was order the o-rings and gaskets right from Honda. It's the first part # under the carburetor microfiche. If yours is a '75, it's the Honda part # is 16010-323-315. My local dealer is showing about $15 for each set.

If you're new to this, Motorcycle Classics did a nice writeup of a carb rebuild a few years ago. I still refer to it:
http://www.motorcycleclassics.com/mc-how-to/honda-cb500-carburetor-rebuild.aspx

[flybox1]

as i mentioned....4into1.com

The kit below contains more than you need, but the cost is about the same as sourcing all soft parts, including shipping.
Just dont use the mainjet, pilot jet, needle, or emulsion tube.  Everything else can be used, even the mixture screws and float valve sets.
Roll the oring off these main jets and put them on your stock ones.
I did this with the 74CB550 I just refreshed and sold.
http://4into1.com/carburetor-repair-kits-complete-set-honda-cb550k-1974-1976/

[JBMorse]

And their shaped float bowl gaskets are a nice touch.

as i mentioned....4into1.com

The kit below contains more than you need, but the cost is about the same as sourcing all soft parts, including shipping.
Just dont use the mainjet, pilot jet, needle, or emulsion tube.  Everything else can be used, even the mixture screws and float valve sets.
Roll the oring off these main jets and put them on your stock ones.
I did this with the 74CB550 I just refreshed and sold.
http://4into1.com/carburetor-repair-kits-complete-set-honda-cb550k-1974-1976/

[flybox1]

And their Viton shaped float bowl gaskets are a nice touch.

Definitely! 

[devinferrante]

And their Viton shaped float bowl gaskets are a nice touch.

Definitely! 

Thanks guys - the kit is supposed to be back in stock next week so I will order ASAP!!

[machacc]

I've had my 550 carbs off about 10 times in the last two weeks.  I remove the 8 nuts holding the castings to the motor, the three cables, gas line, filters, and they slide right out the left side.  Once you have done it a couple of times it only takes about 10 minutes.  It's easier to remove all of it and then take the boots off than to try to do that when they are in the frame.  Ron