New owner of 2008 xl1200c w 35k miles. When l bought it, the bike had been sitting for a while, had old gas, bad battery, and a rough irregular low idel and playing w throttle to keep it going. W new reg gas and a battery the idle cleaned up some but was still rough, and acted like the it was choked with a high idel even when warm. no tach darn it... to be more exact.
took bike to a shop that seems trustworthy for “10 k” service inc new plugs, meah felt that idel due to reg gas and idle issue would clean up w 91 octane gas. changed gas for 91 octane (2 tanks).

Bike starts fine when cold w typical “choked” fast idel and then lowers back down when warm, SOME OF THE TIME.
Bike accelerates fine, but isn’t happy cruising, at steady speed, particularly slow like 5-20 mph in a parking lot. Idle also take a few seconds to fully slow down after throttle released as when pulling up at a red light, and l find myself frequently trying to turn the throttle past the stop, like the cable is too tight. When driving around town, the Idle is almost often fast enough to start bike from a dead stop wo throttle at times.

I know bike is fuel injected and doesn’t have a choke, but it feels like its a partially stuck choked. plan to return to shop but hate having to throw myself on their mercy. Any opinions ?

l put sea f, seemed to help most w micro throttle control at sready freeway speed. Really dont think its mechanical, throttles return is crisp, will look closer at cables etc when time permits, but just got back from trusted shop for service, so,ewhat miffed they missed this, but its subtile.
l think its some sort of temp sensor/response as rpm drops as expected most of the time the fist couple minutes after starting. at first when bikes warm and running. when operating bike is slow to slow down when at the high end of gear ranges, farts and sptters 5-15 mph in parking lots, have to use clutch to slow down via brakes.reminds me of a bsa i had when id forget to push choke in, or more like when i had a kink in the cable and l had to fiddle with it get it to close fully.
have to go, will say more later, plan is to return to shop later in week.

Idle speed is controlled by a measured air bypass (IAC) that is computer controlled. It also controls the t/p at low rpms (parking lot maneuvering). Cleaning the IAC usually cures this condition. Remove the a/f, look into top of the t/b, you will see the IAC hole. Spray carb cleaner or brake cleaner into the hole while holding the throttle open enough to keep the engine running while spraying cleaner into the hole. This should clean out any carbon buildup that can and will slow the reaction of the idle controller.
Bob

Put on another 30 miles mixed city/hwy for total of 50 since adding sf. Sig improvment w idle dropping as expected ~50 % of the time, and w slow 3-10 sec drop ~ 25% now, when fully warn. cruising much smoother now 35-45 in third.
Will try cleaner in IAC next.
many thanks

rest of the story...cleaned iac, no obvious goop seen comming out of hole, whole area seemed fairly clean, freshly wiped out, as expect after l had the air cleaner replaced during service. did discover that the shop had left off a retaining washer for the af cover screw. not much change noted w carb cleaner, but i’ll do it again in a couple days. lm also hesitent to spray too much, remember hearing too much is hard on the valves???.
on another old thread, they suggested turning key on/off x 4 w 10 sec pause btwn, to reset to throttle sensor to factory specs. apparently the comp uses the shut off rpm during the last 4 runs to set idle speed. worked like magic, w ldle speed dropping pretty much as expected around town and low to med acceleration when bike is cold/warm.
when hot, the ilde still stays high, particulary after hard burst runs, but now at least will slow down most of the time in 3-10 sec, as the bike cools, but its still discomforting to come to a light after a fun run and have the idle stay almost high enough to start from a dead stop w/o need for throttle. also don’ t like the way it affects speed control, if l back off the throttle, l want it to back off, not force me to downshift to manage the extra gas the motors getting, or feeling nervous about shiting into first when coasting to a light in second.

Have you checked for intake leak? Intake leak will raise idle speed then the system reads the engine speed and adjusts the speed back down.
Bob

Somewhat checked for leaks via few quick sprays with started fluid around intake manifold but there wasnt enough wind to keep vapor away from ac, but no increase in rpm noted for a couple sec untill i could see the blow off go in the ac.
! did find out that the stock mufflers were switched out for lould open pipes. fo doesnt know if the comp was reprogramed. trusted bike shop doest have access to hd comp network, but thinks maybe if they cant find anything, that putting stock mufflers could solve the problem?
Another option is to go to hd dealer for a comp check

Yes. Well worth the effort to find out and no money spent.
Bob