Topic: 550F Carb Setting question

[Chris Liston]

I'm not sure if I'm running rich or lean on my carbs.  Here are my symtoms.

1st gear when just starting I get some hesitation and just have to modulate the clutch/throttle to get going.  If I work fast and crack the throttle it will hesitate and bog down.  After that the bike runs perfect and pulls very strong through 2,3 and 4 gears into 5th.  While in 5th gear if I go WOT I accelerate but feels very flat and doesn't pull all the strong but does keep accelerating but slowly. 

Its run this way since I got the bike 5 years ago and the carbs/timing and valves,etc.. have all been done by my local Honda shop and they say its running fine.

I am running pod filters with an MCSC exhaust from LoudFastUgly.com (RIP).  The bike ran like this with stock exhaust and pod filters also.   

I'm thinking of putting a modified stock airbox with K&N cone filter on the bike in hope of it clearing it up. 

Any thoughts?

[TwoTired]

Does partial choke improve the throttle response?
Where is the setting for the air bleed screws?
Have you tried turning them all in 1/8, 1/4, or 1/2 turn?

Do you know your current needle position?

What are the sizes of your main and slow jets?

Do you know what the carb set up stamp is on the top right mount flange on each carb?

What color are the Spark plug center electrode insulator deposits? And, are all cylinders the same?

[Chris Liston]

Things that I need to check...  The jets are stock sizes and were replaced with K&S carb kits.  No different than with stock jets on performance. 

Not sure on needle position.  Haven't pulled carbs off to check, not really sure how to check to be honest.

I'll have to check on the carb stamp later, I assume your pertaining to Keihin part number? 

I have not tried turning the air bleed screws.  I'll have to check where they are now and report back.

Thanks

[TwoTired]

Things that I need to check...  The jets are stock sizes and were replaced with K&S carb kits. 

Do you mean K&L?  Did the kits have a setup number on them?

Not sure on needle position.  Haven't pulled carbs off to check, not really sure how to check to be honest.

Honesty works. You have to yank the slides out of the carbs.  Or, pull off the filters and be really handy with small mirrors...maybe.

I'll have to check on the carb stamp later, I assume your pertaining to Keihin part number? 

No the stamp I'm referring to is the set up number.  This style carbs came on three bikes that I know of: the CB500, CB550K, and CB550F.  They were set up differently for each bike and were stamped accordingly; 627B, 022A, and 069A.  (There's a chart of known differences in the Carb FAQ).  I believe K&L provided kits for each of these setups.

I only mention this, because sometimes it's nice to know where you are and what you have, in order to figure out where to go or what the get.
Cheers,

[Chris Liston]

Lloyd,  actually they are keyster kits, my mistake   and they are F carbs   069A according to the carb faq list that was posted earlier this week.

The part numbers for the kits are  KH-0151.

[TwoTired]

That's what they should be for your bike.  But, it is good to make a visual verification to know if they were replaced sometime it the bike's 30 year history.

I looked up the kits.  They have the correct jet sizes for 069A.  I couldn't verify the needle length and profile from the pics or the taper of the air screws tips.  Have to make assumptions they are correct, I suppose.  And, since someone else did your carbs, we don't know where the needles are clipped.  May not matter.  Tweaking the air screws might just get that smile on your face. 
Cheers,

[Chris Liston]

I will try tweaking the screws.  Just one question.  Which way?  Its probably safe to assume that 1 /2 go one way and 3/4 go another?

Just make sure to make a note on where they are before I start turning them

[TwoTired]

They should all be at the same setting.  Turn them in, just till they seat. Count the turns.  That's the setting the rebuilder set for you, I suppose, and is likely the book value for the stock filter and exhaust.

Judging from your problem description and the way mine behaves when they are out too far.  I'm guessing that you will need to turn them in a bit to compensate for the lack of air filter restriction and resultant vacuum in the carb throats. (It would be nice to know your spark plug deposit colors.)  Any way, turning the screws in should help enrich the slow jet mixture and improve the bottom end response to compensate for the lack of strong draw from the venturi.  As I said earlier, a relevant test would also be to apply partial choke to see if the throttle response improves.  If that helps, you then know that you need to enrich the mixture.
Cheers,

[Chris Liston]

really quick and probably last question until I play with the air settings.  turning them in is counter or regular clockwise?

[TwoTired]

The screws have regular threads; righty tighty, lefty loosey.  In:clockwise