Topic: Bike running rich problem fixed!! now it idles too high.....

[78_SaltLick]

thanks for everyones help and suggestions on adjusting the needle settings.....that was the problem...now fixing that one has spawned another one....

So my bike has a 4 into 1 exaust on it, and ran really rich. Ive been complaining about it on this board and trying to figure out how to fix it. I started out with a tune up, that didnt help so...Today (with some help, and bare with me on my terminology) i took out the needle's on the carbs to check out what setting they were on. Sure enough, the little clip thing was on the bottom of the needle, we moved the clip to the middle slot on each needle on each carb,  then reinstalled everything and synced up the carbs, Started it up, and took about an hours ride on it. Before it was spitting and sputtering when it got hot, ran like crap. Now that all went away. It runs like a top. Now the only problem seems to be its idleing way too high and the engine takes a long time to return to idle once you gun the throttle. Ive backed out the idle adjustment screw all the way, brought it down some, but not even close enough. Would this be an idle/air adjustment that i need to do (those 4 screws, one on each carb)? Any help would be appreciated.

[TwoTired]

If you are certain that the intake boot rubbers are sealing properly....

 Have you tried putting the idle air bleed screws back to stock setting?  Moving the slide needles leaned out lot of midrange throttle.  And, it leaks a little at idle.  You reduced the leak, so you may have enrich the idle screws. (1 turn out +/- 1/8)

How's your pick up from idle?  If that is sensitive, too, it's further indication the idle screws need to be put closer to stock setting.
You should be able to be in top gear at 1500RPM and whack the throttle half way open and get smooth (but weak) acceleration.  If it wheezes instead, it idling too lean.

I can't always remember how everyone's bike is configured (mods from stock).  Might get better answers if you state these things with your question.  I remembered you have a 550, though.

Cheers,

[78_SaltLick]

74 550 with 4 into 1 exaust. Returning the settings back to stock with the air/idle screws seemed to do the trick, it brought the idle way down, and got rid of the backfiring. Thanks again twotired. 

[needswork]

Which screw are the air/idle screws? I've got a '78 550K. There are small screws(?) on the undersidenext to the boots connected to the intake manifolds, then there are the screws in the side of the carb bodies. I think I need to make some adjustments.

[78_SaltLick]

Which screw are the air/idle screws? I've got a '78 550K. There are small screws(?) on the undersidenext to the boots connected to the intake manifolds, then there are the screws in the side of the carb bodies. I think I need to make some adjustments.

they are the screws in the side of the carb bodies. stock setting for mine is 1 1/8 turn out from gently seated plus or minus. When i bought the bike they were set at 2.5 turns out, i think he was trying to compensate for the 4 into 1 exaust without having to adjust the clip on the needle.

[TwoTired]

Which screw are the air/idle screws? I've got a '78 550K. There are small screws(?) on the undersidenext to the boots connected to the intake manifolds, then there are the screws in the side of the carb bodies. I think I need to make some adjustments.

The intake manifold screws are removed when vacuum synching the carbs.
If your 78 Cb550K still has the stock carbs, they do not have Idle Air Bleed screws, they have Idle Mixture screws for pilot screws, just in front of float bowls.  They point upwards.  Adjustment of these, is described on page 178 of the Honda Shop manual.  Coarse set to 1 1/2 turns out from LIGHTLY seated.  Then adjust from there to the highest idle speed for each in turn.  Bring the idle speed back to 1050 RPM with the throttle stop screw.

The screws on the side of these carbs (at the bottom of the bowls) control a bowl drain valve.

Cheers,

[needswork]

Thanks guys.
Now I know what to do. I remember the last time I had the carbs out, one of the idle mixture screws was out a lot more turns than the others (I suspect #2 because the spark plug in it was sooty- btw I have 4 into 1 exhaust and pods). However, my carbs do have a screw (?) in the sides of the carb bodies.

[TwoTired]

Can you find numbers stamped or cast into the carbs?  Or, post a pic of the screws you are refering to.

Cheers,

[needswork]

Here it is....there's one on every carb

[TwoTired]

That's the port where the vaccum balance nozzles/adapters insert.  The screw is simply a plug.

Cheers,

[needswork]

That's the port where the vaccum balance nozzles/adapters insert.  The screw is simply a plug.

D'oh! Thanks 2tired-y ou the man.