Author Topic: Wandering idle ('74 CB550)  (Read 925 times)

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klindsey

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Wandering idle ('74 CB550)
« on: March 26, 2010, 12:49:19 PM »
Greetings.
Just finished rebuilding my '74 CB550.  Runs great (although it's a bit underpowered).  Issue is this: after it's warmed up and we're sitting at a traffic light, the idle will wander back and forth between about 1200 and up to 2000.  Sometimes it'll just stick at 2000.  When we get back in gear, the bike's great.
I haven't synched the carbs yet, although I did a valve job a couple of nights ago.  Would out-of-synch carbs cause this?  What else might be a culprit?
Many thanks,
Kevin

Offline Really?

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Re: Wandering idle ('74 CB550)
« Reply #1 on: March 26, 2010, 12:58:49 PM »
Out os sync carbs might, depending on how far they are out.  You may just have a vacuum leak somewhere.
I don't have a motorcycle, sold it ('85 Yamaha Venture Royale).  Haven't had a CB750 for over 40 years.

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The Kid's Bike - 750K3

Offline Duke McDukiedook

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Re: Wandering idle ('74 CB550)
« Reply #2 on: March 26, 2010, 01:05:20 PM »
Out os sync carbs might, depending on how far they are out.  You may just have a vacuum leak somewhere.

+1.
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Offline Inigo Montoya

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Re: Wandering idle ('74 CB550)
« Reply #3 on: March 26, 2010, 01:06:25 PM »
Spray some carb cleaner around the boots and see if idle changes. Quick check often suggested here.

klindsey

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Re: Wandering idle ('74 CB550)
« Reply #4 on: March 26, 2010, 04:44:10 PM »
Good point.  Shudda thought of that first.  I'll do the WD40 thing around the boots and see what gives.