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Hey all,

So over the past couple of weeks I've noticed a little annoyance. My idle 'hangs' for just a moment. Say it drops from 2500rpm's to 1200rpm's quickly, then drops from 1200-1000 over the period of say 1.5 seconds. All guesstimates. No stopwatch or tach here!

I can't really tell sometimes but sometimes I can tell. It's not severe, but it's definitely different. I went ahead and lubed the throttle cables, that wasn't it. Cleaned the throttle body. Any thoughts? The bike is running fine. Just got back from a 600 mile trip. No issues. But it just has that odd second-or-so hang before it returns to idle.

I know that's classic 'lean condition' on carbed bikes, but the bike is mechanically stock (except for debaffled pipes) and has been this way almost as long as I've owned it (debaffled the pipes a couple months after getting the bike, been that way over a year).

Thoughts? Maybe a clogged vent or vacuum line or something? But which one? Where to look?

Thanks,



John
 

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Hi John: That’s interesting! What you’re describing mine has done from the day that I rode it off of the showroom floor. I’ve always had a three tier idle at cold-start; start - fast idle, ramps down to a medium idle after a bit, then settles in at 1000 rpm a short time later.
 

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Correct me if I am wrong but I fully believe the mutli-tier idle at cold start is normal. It's the computers way of getting the juices flowing and warmed up as quickly and safely as possible. Watch and listen to your cage (assuming it's fuel injected) the next time you start it. You will notice a simular pattern in most EFI engines.
 

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Hi John: That’s interesting! What you’re describing mine has done from the day that I rode it off of the showroom floor. I’ve always had a three tier idle at cold-start; start - fast idle, ramps down to a medium idle after a bit, then settles in at 1000 rpm a short time later.
I believe the OP is refering to a fully warmed up engine which would lead one to think mechanical hang up or a sensor heading for failure. He's already lubed the cables and the throttle body shaft.
 

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It's not severe, but it's definitely different.
I believe it's nothing to worry about until you're 600 miles from home. :D

You are attuned to how your bikes and sounds and behaves. I wonder if by chance the change in weather(warmer temps) could affect it. Just guessing here! Have you added seafoam, using different gas, gotten it really wet in a rain storm?

What is different?
 

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Discussion Starter #6
I believe the OP is refering to a fully warmed up engine which would lead one to think mechanical hang up or a sensor heading for failure. He's already lubed the cables and the throttle body shaft.
Bingo.

Not referring to the 'fast idle' that happens when it's cold. This is when it's warmed up. Say I'm cruising down the road, I pull up to a stop sign/light, and the engine spools down, 'hangs', then finally returns to idle.
 

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Bingo.

Not referring to the 'fast idle' that happens when it's cold. This is when it's warmed up. Say I'm cruising down the road, I pull up to a stop sign/light, and the engine spools down, 'hangs', then finally returns to idle.
Is it consistantly doing this, even when the bike is parked? Is it possible to pull the air cleaner off and watch the action of the secondary throttle mechanism to see if that may be the cause?
 

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Is it consistantly doing this, even when the bike is parked? Is it possible to pull the air cleaner off and watch the action of the secondary throttle mechanism to see if that may be the cause?
Will do when I get a chance.

Basically it always does it. But once in a blue moon it won't. The secondary throttle acting up sounds logical!
 

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Rome,
It could be as easy as adjusting your idle screw. I do, periodically when things don't "sound right". My 9 seems to edge up on the idle....or down...on occasion.. Readjusting seems to level it out.
Regards, SH
 
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