Topic: What jets should i use?

[klinger44]

well i bought a bit of a piece of crap/ rat rod / cafe racer 76 cb550 that ran and had been converted to electronic ignition and had good tires and breaks and drives well but it was spray painted black and at full throttle the bike bogged  down a lot. Its hard to get it above 50. Then a few days later a girl i knew asked if i wanted her bike for 800 and it turned out to be a 77 cb550k in complete original condition with 8k miles and runs like a champ and will do a 100 no problem. Im keeping both obviously but i dont know how to get the 76 to run as good as the 77. The 76 does not have a muffler and the guy said he took the 98 fuel jets out and put in 110s because it ran bad with just the 4into 1 header but the jet change didnt change much. Id like to keep just the 4into1 header cause ive seen lots of people have perfectly running bikes like that and i like how loud it is. What jets should be in there run the bike like that.

[Dimitri13]

First step is to put a muffler on it. Second step is to tell us what intake is on it.

[cgswss]

And how about showing us the plugs?  There can be SO MANY things effecting your bike its impossible to tell you how to fix it with the info you have given.  It's easy to check the static timing- so do that too.  Can you get your hands on a compression gauge so we can find out if there is a compression problem.  It sounds like who ever had this bike ragged the H out of it and most likely there are lots of different things wrong with it so we would have to take them one at a time until they are all corrected.

[lucky]

Yes there is a lot of help here, but can you tell us the following:

1976 CB550 F model???
Main jets size.
Idle jets size.
Needle clip position.
Mixture screw turns out.
Intake type.
Exhaust 4 into 1.

My solution...1976 F model.
Main jets size #105 mm.
Idle jets size #40 mm..
Needle clip  move to  middle position.
Mixture screw turns out. 1 turn out.
Intake type- factory air box and filter.
Exhaust 4 into 1 stock HEADER no muffler.

[klinger44]

Factory 4into1 and it has factory intake and clean air filter and clean brand new plugs. And it is a 76 550 super sport. and yeah its been through a lot. 30k miles and what seemed like 10 spray can paint jobs. but its a simple machine and i know i can get it right with some info. Thanx again guys. Sadly my 77 is so perfect its crazy. This is the day i got it

[lucky]

Factory 4into1 and it has factory intake and clean air filter and clean brand new plugs. And it is a 76 550 super sport. and yeah its been through a lot. 30k miles and what seemed like 10 spray can paint jobs. but its a simple machine and i know i can get it right with some info. Thanx again guys. Sadly my 77 is so perfect its crazy. This is the day i got it

For me to help you I need factual information that was asked for above.
It is a 1976 Super sport. Is it the F model or K model ??

I do not need to know how many paint jobs it had.


So the bike you need help with Is the Factory 4 into 1 system.
Factory intake system.

I thought you said the bike in question is a 1976 "Rat Rod" does not have a muffler.
Quote: "The 76 does not have a muffler."


Is this correct???

What are the numbers on the carbs?

[Retro Rocket]

Weren't ALL super sports "F" models... Said it had Factory 4into1 so its definitely an "F"

[klinger44]

Its an F and i thought that all the sports were F. and it only has the factory 4into1 header on it no muffler. and i was commenting that yeah its in ruff shape. And i want to eventually have pods and a new 4into1 header. 100s of bikes run great like that.  I know purists want the factory intake boxes and a muffler. ill start with the 98 again  with the factory settings and it should be fine

[cgswss]

OH!  GEE!  well I'm glad we could help you so much.  I really needed to know what KIND of paint was used so I could recommend the proper jets

[lucky]

Weren't ALL super sports "F" models... Said it had Factory 4into1 so its definitely an "F"

Thanks Retro Rocket.