Slow return to idle
- bikeymikey748
- ICOA Member
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- Joined: Tue Aug 30, 2011 2:52 pm
- Location: Montreal, Canada
- Location: Montreal, Canada
Slow return to idle
Ola folks, I figured I'd move this question over here & try my luck.
Hopefully, you can all save me wasting my time by pointing me in the right direction.
The problem is a slow return to idle .
The bike starts fine, idles well, but as the operating temps rise, so do the revs. I have my idle speed adjuster backed out completely after 5 min. run time ( though it must be adjusted correctly for the, cold, motor to hold it's idle ).
When I exit the highway and get to a stop light, the revs are 1,500 or higher. Strange thing is, if I 'kill' the motor ( with the switch) momentarily, the idle drops significantly. Similarly, if I feed out the clutch ( momentarily ) ,while holding the brakes, the idle drops.
Initially, I was thinking of checking my synch, but now I'm thinking that, perhaps, my mechanical spark advance unit is slow to return . I looked at it, quickly, and it doesn't seem to be binding. I'm uncertain as to how different operating temps may affect it.
I should mention that my fueling/throttle response is excellent ( at all speed ranges, under different loads ). The bike doesn't backfire, or otherwise misbehave. The plugs look great. Throttle cables properly adjusted, and not binding.
Is anyone aware of spark advance unit issue ( my bike is an '82 ) and/or does my problem seem more influenced by poor synch?
Thanks for any help you might be able to provide.
Hopefully, you can all save me wasting my time by pointing me in the right direction.
The problem is a slow return to idle .
The bike starts fine, idles well, but as the operating temps rise, so do the revs. I have my idle speed adjuster backed out completely after 5 min. run time ( though it must be adjusted correctly for the, cold, motor to hold it's idle ).
When I exit the highway and get to a stop light, the revs are 1,500 or higher. Strange thing is, if I 'kill' the motor ( with the switch) momentarily, the idle drops significantly. Similarly, if I feed out the clutch ( momentarily ) ,while holding the brakes, the idle drops.
Initially, I was thinking of checking my synch, but now I'm thinking that, perhaps, my mechanical spark advance unit is slow to return . I looked at it, quickly, and it doesn't seem to be binding. I'm uncertain as to how different operating temps may affect it.
I should mention that my fueling/throttle response is excellent ( at all speed ranges, under different loads ). The bike doesn't backfire, or otherwise misbehave. The plugs look great. Throttle cables properly adjusted, and not binding.
Is anyone aware of spark advance unit issue ( my bike is an '82 ) and/or does my problem seem more influenced by poor synch?
Thanks for any help you might be able to provide.
- NobleHops
- ICOA Member
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- Location: Tucson, Arizona, USA
Re: Slow return to idle
It's got pod filters, right?
N.
N.
Nils Menten
Tucson, Arizona, USA
'82 CBX, among others.
Tucson, Arizona, USA
'82 CBX, among others.
- cbx6ss
- ICOA Member
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- Location: Virginia Beach, Virginia
- Location: Virginia Beach, Virginia
Re: Slow return to idle
I'll bet on a meticulous carb sync...
- bikeymikey748
- ICOA Member
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- Location: Montreal, Canada
Re: Slow return to idle
Yup, Nils, pods.
-
- ICOA Technical Director
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- Location: Knox, PA
Re: Slow return to idle
Choke cable holding choke closed slightly or most likely carb sync. Or some still-plugged idle circuits.
Dave
Dave
- bikeymikey748
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- Location: Montreal, Canada
Re: Slow return to idle
I thought of that too, Dave. But there's all kinds of slack in the choke linkage when its off. I was thinking that, maybe, I'de adjusted the fast idle linkage too high. In the end, it doesn't seem to be the case.Choke cable holding choke closed slightly....
I figure I'll hook up the vacuume gauges tomorrow & see what sort of readings they give me.
- bikeymikey748
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- Joined: Tue Aug 30, 2011 2:52 pm
- Location: Montreal, Canada
- Location: Montreal, Canada
Re: Slow return to idle
Well, who knew that the motor could be so heavily influened by carb balance, huh?
That's all it was. It's not like they were out of spec all that much. True, they all needed adjustment, but only a bit.BIG difference. And, my Suzuki balancing tool did an excellent job. I figure that the previous, poor jetting, issues wouldn't allow for proper readings from the gauge.
For those of you playing along at home, this marks the final piece of the puzzle. That's it, nothing left to do now but ride the wheels off it.
I've a fair length ride this weekend, the 'X' and I are off to get acquainted
That's all it was. It's not like they were out of spec all that much. True, they all needed adjustment, but only a bit.BIG difference. And, my Suzuki balancing tool did an excellent job. I figure that the previous, poor jetting, issues wouldn't allow for proper readings from the gauge.
For those of you playing along at home, this marks the final piece of the puzzle. That's it, nothing left to do now but ride the wheels off it.
I've a fair length ride this weekend, the 'X' and I are off to get acquainted

-
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- Location: St. Catharines, On. Canada
- Location: St. Catharines, On. Canada
Re: Slow return to idle
Great to hear you got that sorted.
Any chance of an on-board clip of one of your jaunts. I would love to hear it run through the gears.
Any chance of an on-board clip of one of your jaunts. I would love to hear it run through the gears.
- cbx6ss
- ICOA Member
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- Location: Virginia Beach, Virginia
- Location: Virginia Beach, Virginia
Re: Slow return to idle
thanks for a great build thread(s). Facinating to track you solving one challenge after another. I learned alot from your project. Here's hoping you enjoy the ride now!! She's a beautiful ride. What have you named her?
/r
Brad
/r
Brad
- bikeymikey748
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- Location: Montreal, Canada
Re: Slow return to idle
Stay tuned, Cadet. I have a few ideas that might be up soon.Any chance of an on-board clip of one of your jaunts. I would love to hear it run through the gears.
Thanks, Brad, nice comment to make.Though, just cruising around this board, it's hard not to pick up some useful info. Soooo many talented/knowledgeable folksthanks for a great build thread(s). Facinating to track you solving one challenge after another. I learned alot from your project. Here's hoping you enjoy the ride now!! She's a beautiful ride. What have you named her?

Named her yet, nope. Any suggestions ?
-
- ICOA Technical Director
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- Location: Knox, PA
Re: Slow return to idle
Excellent job on the bike and equally excellent story to go with it. Gives us all inspiration to do something more. Threads of projects like this keep the forum going. Thanks for contributing!
Dave
Dave
- Jeff Bennetts
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- Location: Ohio, USA
Re: Slow return to idle
Skip the onboard video, have someone follow you with the video camera and how about taking the bike to a bike night and vid people's reaction to it, post it up here.
Have fun.
Have fun.
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- ICOA Member
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Re: Slow return to idle
Good idea, Jeff.
And call your buds at Cycle Canada. It's Showcase time again.
And call your buds at Cycle Canada. It's Showcase time again.