Idle stuck at 3000-3500

[nemuro]

Hi there,

I recently got a 1991 GS 500 E, and I have a bit of a problem. I set the idle for the bike at 1300-1500 RPM, but after I ride for about 10 to 15 minutes, I am surprised to find out that the bike idles at 3000 RPM when I stop at the traffic lights.

I read a small article on setting the idle, and I rode the bike for 15-20 minutes and I tried to lower and increase the idle after which I set the idle at the normal level of 1500 RPM. After this I noticed that the problem with the high idle has gotten worse, and the bike now idles at 3500.

On small fix was to shift into a gear ( first ) and try to loosen the clutch so that the RPM lowers as it struggles to move forward, after witch I pressed the clutch to the max and shifted into neutral.
This worked a few times, but now it's the same problem. After it goes to ~2000 RPM and I shift into neutral, it slowly increases to 3500 RPM.

Hope I explained the things right .

Thanks.

[Train]

Wow, this is exactly the problem I just mentioned to Bhudda in my last post. My 91 has been doing this since last year as well... exactly as you describe. I couldn't find any leaks or similar problems. I combed these boards looking for an answer and didn't really come up with much. Looks like I might send my carbs to Bhudda for some other issues, maybe he'll find the hanging idle issue as well...

[ohgood]

Hi there,

I recently got a 1991 GS 500 E, and I have a bit of a problem. I set the idle for the bike at 1300-1500 RPM, but after I ride for about 10 to 15 minutes, I am surprised to find out that the bike idles at 3000 RPM when I stop at the traffic lights.

I read a small article on setting the idle, and I rode the bike for 15-20 minutes and I tried to lower and increase the idle after which I set the idle at the normal level of 1500 RPM. After this I noticed that the problem with the high idle has gotten worse, and the bike now idles at 3500.

On small fix was to shift into a gear ( first ) and try to loosen the clutch so that the RPM lowers as it struggles to move forward, after witch I pressed the clutch to the max and shifted into neutral.
This worked a few times, but now it's the same problem. After it goes to ~2000 RPM and I shift into neutral, it slowly increases to 3500 RPM.

Hope I explained the things right .

Thanks.

adjust the idle after you bike has warmed up, not before. idle should be set to 1200 rpm. if it surges after setting when warm, you have a vacuum leak.

there are several threads about how to diagnose vacuum leaks. the search function works, sometimes

[bill14224]

My bike was doing the same thing when I bought it, and still does it occasionaly.  Lube your throttle cable, choke cable, and the linkage with WD-40 so it's not hanging-up.  When I bought my bike the choke plunger was hanging-up, not returning all the way.  Shoot the plunger with WD-40 as you pull it out with the choke cable and push it back in with your finger.  Once you've got that plunger and your cables nice and free, don't set your idle until the engine is at full temperature, and that's not until you've rode it for half an hour.  If my idle does surge once it's hot, I hit the kill switch for half a second to bring the rpms back down.  It's better than dragging the clutch.

Ohgood is forgetting one thing.  A sticky choke plunger will also cause the idle to surge.

Buddha has a very good reputation rebuilding carbs.  Enlist his services if you can't sort it out, but this may not be something that's going on inside the carbs, but outside.  They are vacuum-operated, so it's possible they are hanging-up a bit inside.

[Mdow]

yup adj after its totaly warm it took me a little bit to figure that one out.

you can reach the idle adj while on the bike.  so i would ride it around a place with alot of stop signs till it warms up completly and starts idling at 3k then reach under the carbs and turn the adj alittle it. the ride another block to make sure its goign to settle out to were you want it. then just keep doing that till its at about 1-1.2k

[nemuro]

Sorry, I explained things wrong, I adjusted the idle after the engine was warm enough, after a 20 km ride and about 15 minutes. It simply overrides the idle I have adjusted.

[Toogoofy317]

Mine was doing this exact same thing as well. After riding around sixty miles I happened to be going by my dealership and stopped in and they readjusted and has been fine ever since. It was getting very annoying idling at 3500-4000 rpms sitting in neutral at a red light I would engage the clutch ease up a little and it would stop. It also was messing with my fuel consumption as well like only getting 150 miles before reserve then only 20 miles of reserve. Pushing the bike a mile at one o'clock in the morning was no fun.

The service area said that according to the weather that it just occasionally needed to be readjusted some times. They didn't think it was a big deal but they did recommend that it could be getting close to a valve cleaning and such but it seems to have solved my problem.

One other question has your bike been sitting. During this time for me my bike would sit for like a week then I'd go for a while and then it would sit for a week so on and so forth. This was due to health. But, the dealer said that was a very good way to gunk it up!

Hope this helps,
Mary

[fred]

Does it ever jump up to 3000 rpm from idle and stay there? Sounds like you could have a vacuum leak...

[nemuro]

Does it ever jump up to 3000 rpm from idle and stay there? Sounds like you could have a vacuum leak...

Yes, it does.

Is a vacuum leak something that can be fixed by me, or a trip to the mechanic is recommended?

[fred]

Does it ever jump up to 3000 rpm from idle and stay there? Sounds like you could have a vacuum leak...

Yes, it does.

Is a vacuum leak something that can be fixed by me, or a trip to the mechanic is recommended?

Well, in theory you can fix anything. It is worth at least trying to locate the vacuum leak. Get a can of starter fluid, get the tank off, and while the bike is running, spray down the carbs and intake boots. When you spray the vacuum leak, the starter fluid will be sucked into the engine and you'll notice a change in the idle. This should give you a very good idea of where the leak is. My project bike had an vacuum leak around the intake tubes that connect the carbs to the head and it was pretty easy to find with this method. Replacing the intake tubes was also pretty easy. If you don't find a vacuum leak, perhaps it is time to do valve clearances...