Hanging idle; still confounded after research, LONG with a twist at the end.

[birdman]

So far this little procedure here did the trick for my hanging idle.

Try this.

First, I assume you have cleaned carbs or at least run some fuel system cleaner and your bike runs relatively good except you have this hanging idle thing.

Before you get started set your idle mixture screws to 2 to 2.5 turns out. Some factory bikes will have plugs over the mixture screws that needs to be removed.  Requires carbs to be removed and modified by drilling out the plugs.  You will need access to the mixture screws.

Now, take the bike for a ride so the full operating temp is reached.

Stop the bike and leave it idling, if it is idling high load it so that it comes down.

In any case adjust the idle speed screw with your hand down to 900-1000 rpm. Blip the throttle a couple times and make sure it is stable.

Now, turn the mixture screws, 1/2 a turn at a time one side then the next to keep them even.  Do this until you reach a new idle speed of around 1200-1300.

Report your results after you have had a couple of cold starts and hot runs to see if this is a stable setting for your bike. 

birdman

[beRto]

So far this little procedure here did the trick for my hanging idle.

Try this.

First, I assume you have cleaned carbs or at least run some fuel system cleaner and your bike runs relatively good except you have this hanging idle thing.

Before you get started set your idle mixture screws to 2 to 2.5 turns out. Some factory bikes will have plugs over the mixture screws that needs to be removed.  Requires carbs to be removed and modified by drilling out the plugs.  You will need access to the mixture screws.

Now, take the bike for a ride so the full operating temp is reached.

Stop the bike and leave it idling, if it is idling high load it so that it comes down.

In any case adjust the idle speed screw with your hand down to 900-1000 rpm. Blip the throttle a couple times and make sure it is stable.

Now, turn the mixture screws, 1/2 a turn at a time one side then the next to keep them even.  Do this until you reach a new idle speed of around 1200-1300.

Report your results after you have had a couple of cold starts and hot runs to see if this is a stable setting for your bike. 

birdman

Isn't this your own thread? Are you giving yourself advice, or is this meant for theUBS? I'm confused. 

I guess you're posting about how you solved this particular problem?

[birdman]

Does look weird doesn't it?

Yes, I replied with this same info to another thread and wanted to park it here in case someone found it useful.

I am still doing the jets, very lean, plugs are white ashen color.
Also still doing the valve clearance check as a preventative.

[birdman]

Update:
The technique I used above made the bike work fine and there was no hang any more, BUT.

I was still lean for sure.

So today I finished the rejet, 40 and 125 with one washer spacer on the needle. Went well.
Checked Valve shims and found right side valves were both right at .080mm, (.0030")
Left side valves were less than .038mm (.0015")
So reshimmed the left to get .080mm (.003") all around. 

Adjusted the idle mix screws back to two turns and adjusted idle to 1300.  Everything is good and stable.
There is a power dip between 4 and 6 K at WOT, but after 6 K is really takes off.
Also, the abrupt throttle tip-in while cruising between 4 and 6 k RPM has no hesitation. IE throttle response at 40 mph in 4th gear is really nice improvement.

I hope the engine running a little more rich will live longer due to running a little cooler and protecting the valves and pistons from detonation.

Good luck to all.
r