Topic: unsteady idle - pics and video.

[c(b)hris]

'75 CB550K
Pods
4-1

I just did a 3000 mile tune up.
I'm trying to diagnose my idle problems, so I took these plugs out after I warmed it up.
They're 1-4, Left to Right:


Idles fairly steady for about five minutes, even when it's started after already warming up.  After five minutes, the rpms will become unsteady.  What is this a symptom of?  I sprayed carb cleaner around the boots while it was steady and the idle never changed.  My air screws are 1 3/4 turns out from seated.  I just cleaned my air filters(was doing this before I cleaned them).  Carbs have been synced with vacuum gauges.

Here's my unsteady idle:
Rough_Idle.3gp

Did I screw something up with my tune up?  What is this a symptom of?

Thanks in advance.

[Really?]

I am not a pod guy but do you get fuel coming out of the overflow tubes?

[Duanob]

Apparent your number 2 cylinder isn't firing off. Got spark? Got gas in the float bowl? Check the exhaust pipe for heat compared to the rest?

[c(b)hris]

No gas coming out overflows.
I checked 2 for spark before that video and its nice bright blue in the daylight.
Im gonna check the float bowl/pipe now.  Thanks for the tip.

[c(b)hris]

All the pipes are hot.
How long would it take the plugs to foul?  Would it make sense that it starts off ok but starts running unsteadily once the deposits build up?

Thx

[c(b)hris]

When I blip the throttle I get a little black smoke out the tail pipe.   According to the carb faq black smoke out the tail pipe = rich.  The blip is opening the throttle about 3/4.  I'm gonna lean my air screws 1/8 turn and see what happens.  I'm guessing the needle will have to go a little leaner too since the smoke comes out at 3/4.  Does that sound like I'm on the right track?

Thanks in advance.

[phil71]

the sound of the engine reminds me of a vacuum leak. mist some carb cleaner or WD 40 (not ether) at those boots and see if your idle changes.