Topic: 550 carbs

[lee77sf]

Good morning to all, I have been watching the list for about A week Just picked up A '76 550f supersport,first bike in 40 years, my first question concerns the carbs. the Bike has been setting for several years and needs the carbs cleaned. I can't find any carb kits available for the 550f but can find listed for just 550,so did all 550 fours have the same carbs or do I need 550f specific kits?
Thanks in advance for any info.
lee76ss

[bryanj]

Gaskets and o rings same as 550 k0; k1; k2 not sure about jets

[bistromath]

The main jets on the 550F are 98's, whereas on the 550K they are 100's. The carb kits are otherwise interchangeable. If you can't find kits for the 550F, call Western Hills Honda at 513-662-7759. I ordered four 98 jets from them for five bucks or so each just last week.

The bike will run okay on the 100 main jets, but will lose a little power wide open from running rich, and you will need to raise the needle clip to the top position on the needle.

[Caferacernoc]

If your bike has been sitting for a while and needs the carbs cleaned/rebuilt I wouldn't worry about those small jetting differences. The 550K jets will get that thing on the road just fine. And if the bike isn't bone stock it really won't matter. I've had two '76 550's and they both ran the best with 105 sized main jets from the CB500 kit.

[lee77sf]

Thanks for the help I hope that none of the jets need replaceing.Bike only has 6500 miles on it but last registration was from 1989. I am waiting for manual to get here before getting into the carbs to much. I have them off and wrenches in hand waiting.Hope to have it running before winter which is getting closer, comes early to northern mich. 

[TwoTired]

If you look through the Carb FAQ, you will find a chart that lists differences in carbs for the CB500/550.  The stock CB550F carbs used the 069A setup to function well with the stock 4 into 1 exhaust and stock air filter.  If these items are changed, then the jetting and set up of the carbs may need to be adjusted for the different flow characteristics of these items.  Honda thought it was important to change things inside the carbs on a model basis.

The better quality carb kits are specific to particular CB550 models.  But, unless water or acids have been sitting in the carbs, or previous owners have guggered the internal bits, I've not found any reason to replace internal components other than the o rings and seals which harden and crack with age.  All you should need is what is still available from Honda.  You'll have to decide if the bike is worth $80 to rebuild the carbs.

Cheers,

[lee77sf]

thanks twotired the carbs are the 069A and the rest is stock also.the bike is in fine shape so well worth the 80 bucks for gaskets if needed. I'll look in the faqs for the diff between the carbs.

[lee77sf]

  Well I got my manual and got the carbs apart, discovered that there is no leaf spring to hold main jet in will make some this week. Also the inside was really caked with sediment, could have used A chisel to get it off. jets were all crusty but cleaned up ok. also needs new hoses. hope to get it running this week if work doesn't get in the way to much.

[SteveD CB500F]

If you have successfully made jet spring clips, let us know (with photos) as I have seen posts here before from people looking for them.

BTW - if the clips are missing then someone has been in there before you...

[lee77sf]

Steve I made A set today but they are way to stiff. When I find some thinner spring steel I will make another set and send pics,

[lee77sf]

Well I finally got the new leaf springs made. They are .018 thick and 1/2 inch wide spring steel.
I bent them so they have about 1/32 inch of preload when putting the sediment bowl on.It's not much but should be enough to hold the jet in place. I couldn't wait so I started the bike without the airbox in place.It idles with a little help then revs and stalls. will replace airbox and try again.

Dick

[MetalHead550]

Thats fine work man!  May wanna check your timing, valve clearance, and then sync the carbs afterwards.  Installing the air box/filter may make some difference at idle but I dont think it really effects your air/fuel mixture till you give it throttle and the plates/slides are open causing a lean condition.  But then...your choke is fully closed when you start it right.  Good luck!