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Main Area => General GS500 Discussion => Topic started by: jeffdodge on February 17, 2011, 03:17:53 PM

Title: slow rev down
Post by: jeffdodge on February 17, 2011, 03:17:53 PM
I have noticed since I have had this bike (about 600 miles), it has always wound back down slowly when revved. sounds almost like the throttle cable may need to be lubed or the carbs cleaned. Anyone had this problem before?
Title: Re: slow rev down
Post by: tt_four on February 17, 2011, 03:21:18 PM
Your idle might be too high. Try turning it down a little and see if the revs drop faster when you're riding. if you ever pull in the clutch and the revs want to stop around 3krpm, it's the same problem.
Title: Re: slow rev down
Post by: tb0lt on February 19, 2011, 09:46:24 PM
A lean condition will cause slow rev downs. It'd be wise to check the carbs out.
Title: Re: slow rev down
Post by: burning1 on February 20, 2011, 12:09:28 AM
If it's an issue with the throttle, you should be able to feel it. Check that the throttle cable snaps back close when twisted and released.

Hanging idle may be caused by a few things:

1. Leaking intake boot.
2. Choke is on.
3. Idle is too high.

(Others, though I forget what. Check a diagnostic manual.)
Title: Re: slow rev down
Post by: bombjack on February 20, 2011, 07:28:31 AM
Quote from: burning1 on February 20, 2011, 12:09:28 AM
Hanging idle may be caused by a few things:

1. Leaking intake boot.
2. Choke is on.
3. Idle is too high.

4. Tight exhaust valves
Title: Re: slow rev down
Post by: jeffdodge on February 20, 2011, 05:35:35 PM
Haven't messed with it much.. but I have figured out its NOT the throttle cable.. The choke cable might be a little tighter than it should be, Ill be looking into that soon. Doesn't sound like its idling high, to me, but the tach shows about 1800 rpm at idle which is definitely high. I do need to get the valves checked out but I don't know enough about that to attempt it myself so that will be a dealer thing.  :thumb:
Title: Re: slow rev down
Post by: redhenracing2 on February 20, 2011, 08:02:00 PM
Quote from: jeffdodge on February 20, 2011, 05:35:35 PM
I do need to get the valves checked out but I don't know enough about that to attempt it myself so that will be a dealer thing.  :thumb:

It's pretty straightforward, especially if your bike is naked. Just take the valve cover off, turn the cam lobes up as you go around to the different valves, and check it with a feeler gauge. Even if you've never done it before, it can't take more than a couple of hours.
Title: Re: slow rev down
Post by: jeffdodge on February 20, 2011, 10:11:19 PM
since its supposed to snow tonight, i guess i could tackle it tomorrow. What are the clearances supposed to be?
Title: Re: slow rev down
Post by: bombjack on February 21, 2011, 02:56:48 AM
Quote from: jeffdodge on February 20, 2011, 10:11:19 PM
since its supposed to snow tonight, i guess i could tackle it tomorrow. What are the clearances supposed to be?

0.0.3 to 0.08 mm when engine is cold.
There is an excellent video on how to adjust the valves here: http://video.google.com/videoplay?docid=-2015554469142545363#
Title: Re: slow rev down
Post by: The Buddha on February 21, 2011, 11:08:46 AM
Yes tight valves will cause it to suck air and act like its lean, but it wont rev down slowly, it wont rev down at all, like it would idle high and that's it. 3-4K and stay there.
Also tight valves will cause tons of problems just after start up. It will want to die till it fully gets hot.
Check your valves, but you're valves are unlikely to cause just this.
Cool.
Buddha.
Title: Re: slow rev down
Post by: MysterYvil on February 21, 2011, 03:47:08 PM
Souynds like hanging idle to me.  Plenty of great tips here:

http://gstwins.com/gsboard/index.php?topic=41199.0

(Mine turned out to just need an idle adjustment, BTW.  Tweaked it up and down a bit, finally found the sweet spot.)