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Main Area => General GS500 Discussion => Topic started by: dmoore on May 08, 2019, 02:21:00 PM

Title: Hang on deceleration
Post by: dmoore on May 08, 2019, 02:21:00 PM
Greetings. I have a 2006 GS500F that is hanging on deceleration. I did a spray test on the intake boots and both sides surged really high. I had to put it in gear and let the clutch out to stop the surge. So I bought brand new OEM intake boots and o-rings but the problem persists.
There's slightly over 10K miles on the odometer.
The bike starts right up and idles fine so I doubt that it's valves.
There's strong throttle snap back and good free play

At throttle twist, with the bike stationery, there's a delay in deceleration but not nearly as bad as at medium to high speed riding. The previous owner admittedly tolerated this condition so it was like this before I bought it.

The PAIR system has been removed. I'm not sure if some of the carb connections that aren't blocked should be. See the pics.
There are no o-rings or gaskets under the carb caps and the fiche doesn't show any. My other two bikes have o-rings there. Should the GS?
Here's what I've done to date:
Cleaned carb bodies in ultra-sonic cleaner
Sprayed all passages with carb cleaner
Sprayed all jets thoroughly with carb cleaner
Rubber and needles all look new so someone must have been in there recently
Floats move up and down freely
Installed new intake boots and o-rings
Boot screws are tightened down firmly
Intake boots and air box clamps are tightened down firmly
Installed brand new air filter
Slide diaphragms look good although I will check them again
Any help will be greatly appreciated.
Thanks. D
Title: Re: Hang on deceleration
Post by: mr72 on May 08, 2019, 02:53:19 PM
sounds like the idle is just set too fast.
Title: Re: Hang on deceleration
Post by: dmoore on May 08, 2019, 03:43:38 PM
 It idles around 1100 rpm.
Title: Re: Hang on deceleration
Post by: mr72 on May 08, 2019, 04:53:33 PM
Quote from: dmoore on May 08, 2019, 03:43:38 PM
It idles around 1100 rpm.

That is only remotely related to the idle speed setting.
Title: Re: Hang on deceleration
Post by: dmoore on May 08, 2019, 10:42:19 PM
OK. Please tell me more.
Title: Re: Hang on deceleration
Post by: mr72 on May 09, 2019, 04:20:11 AM
Setting the idle mixture (and speed, which is mostly affected by mixture) is near the end of this post:

https://joshkarnes.blogspot.com/2017/09/fixing-common-gs500-carburetor-issues.html

Title: Re: Hang on deceleration
Post by: Cincykz on May 09, 2019, 05:14:40 AM
Also, the pictured white plastic male 'nubs' are sealed and do not require hoses or caps.
Title: Re: Hang on deceleration
Post by: dmoore on May 09, 2019, 06:09:49 AM
Thanks, mr72.  I read the article. Good info.
Title: Re: Hang on deceleration
Post by: dmoore on May 14, 2019, 12:49:50 PM
There's supposed to be a little o-ring from the diaphragm covers that apparently gets lost when they're taken off. I don't see anywhere an o-ring would be here. ???

Title: Re: Hang on deceleration
Post by: Meukowi on May 15, 2019, 03:48:47 AM
Quote from: dmoore on May 14, 2019, 12:49:50 PM
There's supposed to be a little o-ring from the diaphragm covers that apparently gets lost when they're taken off. I don't see anywhere an o-ring would be here. ???
seems like you've got 2000+ bike, if i remember right i've read that they dont have it, on my -92 theres o-ring at the vaccuum cap, where you synchronize the carbs
Title: Re: Hang on deceleration
Post by: dmoore on May 15, 2019, 05:20:34 AM
I was thinking that might be the case since the older bikes are different in certain ways. Thanks.
Title: Re: Hang on deceleration
Post by: dmoore on May 15, 2019, 05:21:49 AM
This is a 2006.
Title: Re: Hang on deceleration
Post by: Kookas on May 15, 2019, 11:10:12 AM
Quote from: dmoore on May 15, 2019, 05:20:34 AM
I was thinking that might be the case since the older bikes are different in certain ways. Thanks.

Worth noting the pre-2000 (2001?) carbs are pretty much completely different.
Title: Re: Hang on deceleration
Post by: dmoore on May 15, 2019, 02:21:03 PM
Bingo! It was the mixture screw settings. They were only 1.5 turns out. Way lean. I turned them 2.5 out and it runs perfect! Thanks folks for your help.