Topic: Blarg. Still hanging idle... 1976 CB550K

[OldGreyBeast]

This is what it looks like setting it with a 1/8" drill bit from the airbox side.  It looks the same as his to me.

[Deltarider]

I don't know why the drill bit method is parroted over and over again. For me a small allen key under the slides frontside worked best for setting them equal. Then  final readjustment of the rack by the big idle knob and Bob's your uncle. The other day I thought of maybe another, even more refined method. I didn't try it out myself, but anyone is invited to test it out. Have 4 identical small allen keys under the slides engine side and position them thus that they more or less dangle, meaning only their very end is under the slides. Now adjust slides so that the allen keys all 4 dangle at the same angle. I hope you understand what I mean. Please report if it works.

[Scott S]

This is what it looks like setting it with a 1/8" drill bit from the airbox side.  It looks the same as his to me.

 That's not the airbox side.
 The airbox side has the choke plates.

[Deltarider]

This is what it looks like setting it with a 1/8" drill bit from the airbox side.  It looks the same as his to me.

 That's not the airbox side.
 The airbox side has the choke plates.

Why nitpick over these minor details, Scott?

[Scott S]

This is what it looks like setting it with a 1/8" drill bit from the airbox side.  It looks the same as his to me.

 That's not the airbox side.
 The airbox side has the choke plates.

Why nitpick over these minor details, Scott?

 Because the air box side has the cut outs on the slide, and if he was setting the slide height on that side to the tiny gap, which is what he said he was doing, that would be wrong and could possibly have been the cause of his problems.
 The gap on the air box side, when set correctly, is much larger than that.

[wolf550]

This is what it looks like setting it with a 1/8" drill bit from the airbox side.  It looks the same as his to me.

I hear ya but his seems to have a smaller opening on his while the carb on yours is allowing somewhat more of an opening.
if this makes a difference I could not tell you
but I am rooting for you to find out the cause of this darned hanging idle with every possible choice.

[OldGreyBeast]

I set the airbox side gap to 1/8".  I took a picture of the engine side gap because that's what the 95chris took pictures of in the post you referred to before.  I can take a picture of that but I don't see the purpose in comparing the airbox side gap to the engine side gap.

[HondaMan]

Umm...have you replaced the O-rings in those intake castings where they seal against the intake ports? The O-ring is the same size as is in the valve caps.

[95chris]

I set the airbox side gap to 1/8".  I took a picture of the engine side gap because that's what the 95chris took pictures of in the post you referred to before.  I can take a picture of that but I don't see the purpose in comparing the airbox side gap to the engine side gap.

I don't remember the exact method I used 7 years ago but the photos in this reply makes me think I may have done it through the airbox side as well. I happen to have a spare set of 022A carbs so I thought I take a few photos of what's being asked. Here's a 1/8th drill bit that's just held tight enough to hold it in place (I moved it a bit to the side to take a straight on photo). Also included the engine side as well the the adjuster threads.  Done on the #3 carb, idle knob is not engaged.

Because the air box side has the cut outs on the slide, and if he was setting the slide height on that side to the tiny gap, which is what he said he was doing, that would be wrong and could possibly have been the cause of his problems.
 The gap on the air box side, when set correctly, is much larger than that.

Whichever side I did use (probably the airbox side like the image above) set the gap fairly close to what I posted in my previous post. It's possible I may have just use the drill bit as a baseline and closed them further as evenly as possible during that time to limit the amount of light passing through. Maybe a carb sync can confirm those small differences but still waiting on my sync tool  . Slides were not adjusted during this time of this thread or when I pulled the carbs to change the main jet o-rings. Can't explain the difference in the amount of threads shown however... 

Chris

quick edit: My apologies for the insane size of these images, just realized how absurdly massive they are if you click on them here! Open them in a new tab to size it to your monitor. I'll see about resizing them a bit better for viewing.

[OldGreyBeast]

Umm...have you replaced the O-rings in those intake castings where they seal against the intake ports? The O-ring is the same size as is in the valve caps.

Indeed, I replaced those a few months ago.  I've sprayed carb cleaner all over the carb area and have confirmed there's no vacuum leak going on.

EDIT: 95chris, I'll be interested to hear how your vacuum sync goes.

[wolf550]

I set the airbox side gap to 1/8".  I took a picture of the engine side gap because that's what the 95chris took pictures of in the post you referred to before.  I can take a picture of that but I don't see the purpose in comparing the airbox side gap to the engine side gap.

Just saw that. My mistake

[OldGreyBeast]

That reply was meant to go to Scott, sorry, should have used the quote button.

I did see your post comparing the gap, with those yellow lines it does make it more obvious there's a difference, but that gap isn't so large that it couldn't be made up with the idle screw.  I was hoping to get to take it for a ride and see how it performs real-world yesterday but had to work late.

[dave500]

mechanical sync gets it ball park,then you vacuum sync,bit like timing by ear or static then use a strobe.

[Kevnz]

Not that it's terribly relevant here, now, but this is what I use for bench synching. Gas torch tip cleaners, use like feeler gauges, better selection of fine tips than you probably have in your drill selection.

[Coliver24]

Any updates on this oldgreybeast?
I'm still having the same issue

[bryanj]

I say drill bit as more people have small drill bits than tiny allen keys which get lost cos there are no screws for them to fit

[OldGreyBeast]

I've just been riding mine and dealing with it.  I've put about 600 miles on it with the hanging idle.  I just ride the brakes to force the engine down.  It doesn't do it as bad as it used to.

Rebuilt the carbs the exact same way on my '75 bike and it idles like normal, so the only thing I can figure is it must be pitting around the main jet or a crack in the carbs somewhere letting extra air through.