Topic: 550 carb problems

[BruceA cb550]

been adjusting carbs for several weeks now due to too rich condition.  Have needles set on leanest setting and bike runs great above 2000 rpm, plugs look good and mileage is about 45mpg, was 30mpg.  bike has shorty headers, factory filter, and I dont know what jet is in it, used what came in the rebuild kit.  Air mixture screw is out 2 turns, adjusting doesnt seem to help.  All other tuning is correct.  Very recent rebuild with tank cleaning and new fuel filters.
Bike has no power and dogs easily under load from idle to 2000 rpm.  This problem arose after the last needle change.
need ideas on what to check next.

[Klark Kent]

how did you synch the carbs?
-KK

[csendker]

Use this chart to help identify where to start looking: http://www.sohc4.us/forums/index.php?topic=10841.msg102069#msg102069

Low throttle issues revolve around the air screw and clip position.  Air screw for a 550 is 1-1/8 to 1-1/2 turns out; year dependent --> http://www.sohc4.us/forums/index.php?topic=5410.0. 

If adjusting the air bleed screw does little, then maybe you overdid it one too many clip's.  Try backing off one clip and see what happens.

[BruceA cb550]

synched carbs with gauge setup.  gauges measure barometric pressure instead of inches of vacuum but did get all carbs reading the same so I assume they're synched.  Plug chop at prior setting indicated slightly rich setting and engine would tend to surge a little.  Plug chop on new setting (needle full lean) looks much better and engine doesnt surge at all but now have the idle problem.
Thinking about going back to prior setting and using a different filter, might be able to lean it a little that way.  I do have a set of pods but am reluctant to use them after reading all the negative threads about pods.

[csendker]

I'm running a Uni foam drop-in to the stock air box.  Works great with little impact on the carb set-up.  It should breathe marginally better, possibly leaning out your mix just a bit.  Although they work great for others, pods do seem to have too much hassle for my taste.