Hanging idle

[Eydugstr]

Has anyone here ever experienced a hanging idle? Once my bike ('90 with 62k) is warmed up, now it's developing a routine where it idles high (1200-1500 rpm) Sometimes I can blip the throttle and it will go away; other times it stays high. I've tried adjusting the idle knob (which does help but makes it hard to start from cold), have tried spraying carb cleaner to find find a vacuum leak (no luck whatsoever), ran seafoam through a tank of gas (no real change), lubed the cables, and have done a carb synch (which did help with the chain rattle a lot, but didn't do anything for the hanging idle).

Outside of blocking off the smog stuff, or rebuilding the carbs, is there anything else I can try?

[Me Again]

If you can change it by just flipping the throttle then you probably just need to adjust the cables.
Throttle is spring loaded and if the cables are not set correctly it will act up

[cranky]

... run a few consecutive doses of Seafoam thru 'er and clean out the
carb system.... JM2C

[triton28]

The carb spring is extremely well designed to return the throttle valves to an idle position on a clean well working set of carbs with no fetching up of the throttle valve spindles.
Now if one adds in all the cabling to operate the carbs and all the cabling is internally clean, well lubed and the cables are not pinched/kinked/improperly routed the spring is still strong enough to work as intended provided, as Me Again stated, the adjustments of the cables are correct.
There isn't much else can cause your symptoms as a quick blip of the throttle is to me anyway, the dead giveaway----cabling or less likely, binding throttle valve spindles.
Just my take on it but others may have a simpler reason.

[Nails]

I had good success with one of those cable cleaning units that forces the spray from the can down the cable. A cable cleaner. You have to wrench a bit to get to everything.

[Eydugstr]

TY for the responses everyone. Did adjust the cables, but with the adjusters by the throttle handle. Will double check the adjustment at the carbs and make sure the cables are routed correctly.

[Barry]

I had some unexpected carb problems earlier this riding season. I ended up getting a set of rebuilt ones from Carl Leo. He has some magic he performs during the rebuild. One of them is polishing the slides. I can't tell you what an amazing difference that makes. Now when I pull in the clutch and snap the throttle closed, it's like hitting the kill switch. Before it just dropped down to idle as if there was a flywheel on the motor. Swapping out my California carbs with the ones he sent gave me a different new bike. It's so much fun the fuel economy is suffering some. I can live with that. Give Carl a call. He won't try to sell you anything, but will give great advice. If you do need any parts, there's a good chance he has them at a fair price.