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Discussion Starter #1
I'd just left work this afternoon when the idle suddenly shot to about 3k rpm. It stayed there for the rest of the trip home. Not much fun around town.

I'm going to have dinner before I go down and adjust the idle. Just thought I'd throw in a quick question to see if anyone had idea's of what could have caused the sudden change. Aside from the sudden change in idle the bike appears to be running normally. No change in idle speed when I move the bars from side to side, no noticeable loss of power, no difference in sound that I can detect.

I use the choke when warming the bike up. I can confirm that I turned the choke off and that the bike went back to normal idle before I took off. The idle speed shot up about 10 seconds afterwards.
 

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You didn't say what model, but I assume an i.e. bike.

My advice is *NOT* to simply try to adjust the idle downwards using the throttle stops. That's just not the correct procedure here. Either something is stuck (i.e., it is not returning all the way to the throttle stops), or, much more likely, you have developed a vacuum leak.

I had essentially the exact same thing happen on a 2000 750SSie. I never solved it myself, but a mechanic eventually traced the problem to a failure in one of the gaskets on the throttle bodies. Any leak between the TBs and the head will cause the symptoms you describe.
 

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Old Wizard
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The button is not a choke, it simply cracks open the throttle grip a little. Try turning the grip backwards. The button is probably stuck or needs lube.
 

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I had a problem similar to this one when I low sided my SS earlier this year. Check your cable that runs through the center of your triple tree (I think its the "choke" cable"). Mine got stuck and was pulling open the throttle that is on the right side of the bike, just below the frame. I just re-routed it and all fixed.

CC
 

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Discussion Starter #5
Thanks for the replies. First off, this is a 92 model so carbed version.

I've adjusted the idle for now as I need to get to work today. Did a carb synch as well. There was only a very slight difference between them. Would this essentially rule out a leak around the throttle bodies?

I'll check the "choke" cable before I head off and make sure it isn't stuck on.

I'll see how it performs today and see what other info I can add.

So what exactly do you call a choke that isn't a choke? :)
 

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Excel Addict
2001 900SSie
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5,345 Posts
Choke

Now that people know the bike is a carb version, it is a choke. I.e. you can richen the mixture by reducing available air as choke lever pulls the cable and hence slide in the carb. Less air for a given amount of fuel from the carb.

On EFI models, the amount of air is not controlled, so the "choking" effect is achieved by injecting more fuel into the available air to make the mixture richer. The lever on the left bar is really just an idle speed controller whilst the ECU does its job to manage the EFI. Like a choke, this can be reduced as the bike warms.
 

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I know we are getting off topic here, but I thought the fast idle lever on fi bikes just held the throttle open a bit, just as if you held the throttle open yourself with the twistgrip (?)
 
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