Author Topic: Shaking at idle  (Read 3400 times)

Stig / Major Tom

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Re: Shaking at idle
« Reply #15 on: March 21, 2019, 11:29:03 PM »
1500 rpm idle is a bit slow (1700 is normal) Try increasing idle speed a smidge to see if you have a resonance that goes away at a higher idle speed. On the center stand It's OK for the rear wheel to turn a bit at idle, as long as the bike doesn't want to move when you are on it and stopped at a light. You should be able to sit on it and not feel it trying to move when stopped, ie, not need the brake to keep it stopped.
Kind of agree here....if idle is a little low on most any engine it will shudder a bit --- then smooth right out at speed.
Stig
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CROSSBOLT

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Re: Shaking at idle
« Reply #16 on: March 22, 2019, 11:00:30 AM »
Idle fixed on the DT300i.....
Karl

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stuo

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Re: Shaking at idle
« Reply #17 on: March 22, 2019, 07:20:06 PM »
Karl has a point: it's fuel injected so no adjustment to increase idle speed. What to do???
2009 GV 250

Stig / Major Tom

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Re: Shaking at idle
« Reply #18 on: March 22, 2019, 07:31:35 PM »
Karl has a point: it's fuel injected so no adjustment to increase idle speed. What to do???
I think you can remove the throttle end free play at the throttle body - in effect 'giving it a little gas' at opposite end of throttle cable from the grip.

Me, first thing I'd do if this is indeed idling below specs is install the correct Iridium spark plug.
These plugs always improved my idle strength (speed?) somewhat.
Stig
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CROSSBOLT

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Re: Shaking at idle
« Reply #19 on: March 22, 2019, 10:33:29 PM »
The ISC, Idle Speed Control, a motorized valve that bypasses a CLOSED throttle plate admits enough air to keep the fire lit at idle. So when the computer senses the throttle is closed, this valve motors open. When you twist the throttle the ISC motors shut. A slow idle speed is "probably" caused by this valve not opening far enough or the passage is partially blocked.
Karl

Three motorcycles 1960-1977 (restored a 1955 BSA)
Agility 50
Yager 200i
Downtown 300i
Navy tech, Ships Engineer, pilot and aircraft mechanic

stuo

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Re: Shaking at idle
« Reply #20 on: March 23, 2019, 09:43:48 PM »
I'm putting my money on Karl's analysis. Any takers?
2009 GV 250

Stig / Major Tom

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Re: Shaking at idle
« Reply #21 on: March 23, 2019, 10:29:41 PM »
I'm putting my money on Karl's analysis. Any takers?
I can't understand any of it when he gets all technical......but his avatar pic is very impressive.
So, I vote with Karl.

Stig
we need a scooter pic in here.....
« Last Edit: March 23, 2019, 10:32:49 PM by Stig »
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CROSSBOLT

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Re: Shaking at idle
« Reply #22 on: March 23, 2019, 10:42:20 PM »
How is that motorcycle inna picture staying upright without a sidestand?
Karl

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Yager 200i
Downtown 300i
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cb325

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Re: Shaking at idle
« Reply #23 on: March 24, 2019, 09:40:36 PM »
1500 rpm idle is a bit slow (1700 is normal) Try increasing idle speed a smidge to see if you have a resonance that goes away at a higher idle speed. On the center stand It's OK for the rear wheel to turn a bit at idle, as long as the bike doesn't want to move when you are on it and stopped at a light. You should be able to sit on it and not feel it trying to move when stopped, ie, not need the brake to keep it stopped.

Mine wants to move forward when stopped if I don't have my brake on. What do I need to check or replace to get it to not do that anymore? It has a pretty new belt, so maybe rollers? It is quite annoying and makes it pretty difficult to back up.

stuo

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Re: Shaking at idle
« Reply #24 on: March 25, 2019, 07:20:13 PM »
Idle speed is the easiest, quickest, most probable cause: slow engine idle speed down if you can. If that doesn't work, the next I would try is rollers: are they stock weight? While you are in the CVT inspect and possibly  replace the belt. It isn't the cause of the creep but you don't want to have it break, right? Mine broke after 1000 miles because I bought a cheapo belt. (Just sharing my stupid mistake...)
2009 GV 250

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