550f running rich?

[DomP]

With this in mind might it be worth trying my needle clip one lower, which on an F will be the last position.?  All of my parts are genuine Keihin and correct for carbs/bike

If you put the clip one groove lower that will raise the needle and make it run richer.

Try going the other way, put the clip one groove higher to lower the needle.

Sorry Gareth thats what I meant to say, its the last clip position so im not going to get any lower than that, im hoping ill have enough range to play with the air screw in this position

[K2-K6]

Dropping the needle will primarily affect the mid range response  .... if that wasn't wrong, it should then produce a flat spot as the throttle opening transitions from low speed into that range.
In effect, you'd be moving the two parts further alway from each other as it'll not change (much) the lowest point metering. Low would stay rich and mid would move toward lean.

If it's definitely rich at low slide opening, then it's usually the idle jets (assuming the others aren't nuts in volume)  and so you'd correct with them by going smaller idles.

Of interest, what absolute vacuum reading is shown on the sync gauges if you use them  ? 

This complexity is why I'd be absolutely sure of cam timing before you begin diagnostics of carbs. If wrong, it'll run you ragged trying to think what you can adjust or the permutations of error ... all in vain too.

[McCabe-Thiele (Ted)]

Are you on the original air intake/ filter system?

[DomP]

All standard except the 500 filter change with a genuine honda one. I purposely have tried to keep it standard to make tuning straightforward....obviously that bit hasn't gone to plan as yet

[DomP]

Before I lose an afternoon (and knuckles) of my life dropping the needles, in the opinion of the honda gods is this worth trying?

[deltarider]

Depends. What is the prescribed position and what is yours now. I've changed the needle's position (CB500) out of curiosity and there wasn't that much effect, just like a Honda mec had said. I'd stay close to the original settings.
Leaking O-rings on the main jets have to be excluded, as well as accidently reamed slow jets.
Aftermarket air intake can make a difference, aftermarket exhaust hardly at all.
The correct fuel level in the floatbowls can easily be checked by applying this method: http://forums.sohc4.net/index.php/topic,185754.msg2151647.html#msg2151647.
Without having read all the above, make sure air intake is unobstructed, the airfilter element is good, meaning not moist or fouled by crankcase fumes.

[DomP]

Standard for an F is 2nd slot from top so I'm proposing using the very last slot

*Little update, I did this today by extracting the needles through the top of the carbs while still fitted which is a whole lot easier.  It then wouldn't start off choke which is encouraging as before it would start with no intervention at all.  I made the battery a bit weak while trying so stuck it on charge chopine listening to the football.  That's as far as I got, can't rush these things!

[ozzybud]

Standard for an F is 2nd slot from top so I'm proposing using the very last slot

*Little update, I did this today by extracting the needles through the top of the carbs while still fitted which is a whole lot easier.  It then wouldn't start off choke which is encouraging as before it would start with no intervention at all.  I made the battery a bit weak while trying so stuck it on charge chopine listening to the football.  That's as far as I got, can't rush these things!

Please remember after you change the needle positions in place or on the bench you will need to start the bike and get it warmed a bit and do a vacuum sync before test riding.
You will.never get the arm positioned in the same place. On the shaft it was before and your synchronization will be all.over the place.
If not synchronized  it will mimic lean and rich conditions on the plugs after a ride.
I believe  it is the most important step when tuning.

[DomP]

Cheers Ozzybud, I'll make sure I resync them before going any further

[DomP]

I've spent a few hours in the evenings pottering about with my 550, after dropping the needles to their lowest setting I re-synced the carbs and tweaked the timing a touch to be ever so slightly past the advance mark.  Pleasingly it is now more difficult to start with no choke from cold which previously was easy even on cold days so hopefully if I get a chance to get it out soon I will be able to see how it runs, ive reset the aircrew upto factory as a base line to work from.