Topic: Can I use different carbs?

[btripp]

Hi guys,

  Sorry I haven't posted in a while.  Everything's been too busy!

  So I've got a question.  I'm still working on my bikes original carbs (see pics in previous post and you'll know why)  so they're not ready to put back on yet.  However, I have another set of carbs that are pretty much ready to go.  I was wondering if anybody knew the specifics of any jetting/tuning issues I might face with this swap. 

  The only problem is I can't remember exactly what bike the carbs are from.  I believe they're from a 1977 CB550K.  My bike is an F of the same model and year.  Keep in mind my exhaust has rusted out too, so I could possibly change it what whatever the K used.  Had a 4-1. 

  I was thinking maybe I could throw these on and go without too much trouble while I get the originals real nice, but I figured I'd better seek the wisdom of the board first!

  Thanks!  -Ben

[volz1fsu]

Are there any #s on the carbs.  My '75 550 carbs are 022A, the numbers on the mounting flange of each carb.  Don't know if '77 carbs would be the same type.  What do you want to know about the jetting?

[TwoTired]

If you wish to use the 77 CB550K carbs on a  77Cb550F, you will need to change the intake manifolds and couplers as well.  The carb spacing is different.

Cheers,

[btripp]

The original carbs are 069A. 

  After inspection of the other carbs, I don't think they're for anything close my bike.  It looks really different...  Maybe I have another laying around here somewhere? 

  Are the 069A carbs the right ones for this bike? 

  Thanks!

  -Ben

[78 k550]

    Are the 069A carbs the right ones for this bike? 

  Thanks!

  -Ben

Yes those are the right carbs for the F model. 069A.

Paul

[csendker]

The Carb FAQ has a table identifying the different models & jet sizes for 550's:

http://www.sohc4.us/forums/index.php?topic=5410.0

[btripp]

Excellent!  Thank you.

  I've purchased some of the much talked about Yamaha carb cleaner to really get at these things (old carbs), so look for a new post on that soon. 

  Hopefully with pics!

  Thanks everybody!

  -Ben

[btripp]

BTW:  As far as the Yamaha carb cleaner goes...

  I checked with the Carb FAQ and the info listed there states that the cleaner will no harm rubber parts.  Can I take that to mean I can submerge the entire carb rack, without any disassembly?  No problems with the little gaskets and seals? 

  I thought I remembered something about it eating those...

  The whole thing is gummed up and rusted and nasty almost beyond comprehension.  I'm afraid to apply too much force to some parts in order to remove them (screws etc) so I'd really like something that could soften things up.  Plus, after a can of spray on carb cleaner, the floats still don't move very freely and there's a lot of crud.  I've even rubbed with a toothbrush and cleaner to try and get the stuff out.  The PO just let gas sit in it for years and years, and then water got in it.  She's been sitting for about ten years as I recall.

  Thanks guys!

  -Ben

[n9viw]

Considering the possible condition of whatever rubber you may find in there anyway, I'd just dip the whole rack in whatever, regardless of whether it'd eat rubber or not. At least it will be easier to get in to, and you can still get full rebuild kits for these carbs from Partsnmore and CRC2. Sure beats breaking off a gummy float bowl screw, or scratching a slide on a bit of grit as you remove it.

[csendker]

I tossed the entire rack in, I had 2 stuck floats, numerous stuck screws, lots 'o gunk.  Both floats came un-stuck, and every screw has (so far) came out.  All of the rubber o-rings ended up shot, but I think they were before I dunked them.  There was no discernable issue with the manifold rubbers.  In fact, they seemed to be a touch softer when I pulled them out.

[btripp]

Thanks for the info on your experience guys! 

 You're take is pretty much what I was thinking too.  I REALLY don't want to tear something up or strip a screw (so far everything has been a real B to get out) so I think I'll just dunk them and the heck with the rubber. 

  Thanks for the info about the rebuild kits!  I'd been looking for a good place to get them.

  I'll let you guys know how it goes and post a few pics!

  Thanks!  -Ben