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Main Area => General GS500 Discussion => Topic started by: OPTheory on November 04, 2007, 01:57:52 PM

Title: Bad Surging, 4K RPM idle after attmpted handlebars installation
Post by: OPTheory on November 04, 2007, 01:57:52 PM
Hey Guys,

After trying desperately to put on some '96 bars on my '89 I found that it will not work.  The cables and wires are all shorter on the 1989 model and since the '96 handlebars extend out a few more inches, the process of getting everything on was a nightmare and I even broke the choke cable in the process.  I did get everything on, but I realized that if I turn the front wheel in the slightest, all of the cables and wires get very stretched.  So I took everything off again and put my '89 bars on once more with no problems (much frustration though since I wanted the higher and wider bars - I was so close).  The bike started up just fine and off to work I went.  The first stop I came to, the bike idled at 3K RPM's - before I attempted to put on the others bars, it would idle at around 1.2K to 1.5K with no problems.  If it ever idled any differently it was always because the idle screw had been toyed with.  I figued that the bike is idling so high probably because the choke cable broke and those choke cylinders on the carbs are probably pulled out.  That wasn't the case though so I had to rule that out. 

It always takes a few good minutes of solid riding to get that 4K idle but sometimes the surging I get is just ridiculous.  If I were to go outside now and start the bike up, the idle would jumps from 1.8K to 2.2k RPM.  It seems to 'hiccup' for lack of a better term.

Again, I never had these problems before I tried putting on the other bars - everything was solid. 

Any theories as to why this is the case?  I'm just stumped.
Title: Re: Bad Surging, 4K RPM idle after attmpted handlebars installation
Post by: GeeP on November 04, 2007, 02:02:35 PM
Does the engine rev when you turn the bars hard right or left?

I bet you need to adjust the throttle cable slack.  The manual suggests 3/16" at the periphery of the throttle grip, but I suggest the least play that prevents surging.

BTW:  New cables are cheap.  Around $15 or less each as I recall.   :thumb:

Oh, you might try putting your '89 setup on the "for sale or wanted" section.  There's always somebody that wants a nice stock clipon set, and it will pay for new cables too.
Title: Re: Bad Surging, 4K RPM idle after attmpted handlebars installation
Post by: OPTheory on November 04, 2007, 05:02:05 PM
Thanks for the suggestions GeeP!  Yeah I actually should have mentioned that it doesn't rev when the bars are turned to a full left or right.  Another strange thing I've noticed is that when the engine idles above 2.5K, the right side of the engine block will make this loud CLICK and the RPM's will go down momentarily after that happens.  It's very strange.

I've tried giving it all the slack possible and it still has problems idling at a high speed. 

I'd love to have my some older bars on the bike but the only thing that will work on an '89 are the clipons!
Title: Re: Bad Surging, 4K RPM idle after attmpted handlebars installation
Post by: GeeP on November 04, 2007, 05:29:06 PM
Hmm...  You say you damaged the choke cable...  With the engine running, push in the choke plunger slide.  Does the engine throttle down?  I'd have to go out and look at mine, but I think the spring that holds the slide in is a little weak.
Title: Re: Bad Surging, 4K RPM idle after attmpted handlebars installation
Post by: OPTheory on November 04, 2007, 10:00:08 PM
Tried that too! Those plungers are somewhat spring loaded, so if I push them from the right side the RPM's shoot up about 4K more RPM's than it's sitting at so it's definitely not in the choke position.

Again with the random clicks while I'm at idle - it'll be at 3K or so RPM's, I'll hear this strange click and it will go down to 2K but hiccup it's way back up.  I'll try lubing the cable tomorrow just for the sake of getting it done - hopefully, it's as simple as that!  From what I've read around the forum, the random clicking is nothing to really worry about but the reason I'm bringing it up is because it could be connected to my problems but who knows!

Thanks!
Title: Re: Bad Surging, 4K RPM idle after attmpted handlebars installation
Post by: GeeP on November 05, 2007, 06:10:18 AM
Grr!  I'm no help huh?   :laugh: :mad:

Sounds like it is misfiring, which isn't normal if the bike is in tune.  However, I don't think that is your problem.  Especially since it started with your work on the bars.  You can also get a random, high pitched, "clunk" from the camshafts.  That's normal, but shouldn't change the engine speed at all.

Have you checked the idle screw, and are you positive the butterflies are landing on the idle screw?