Author Topic: 550 Throttle return  (Read 639 times)

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Offline exponent

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550 Throttle return
« on: March 19, 2021, 05:12:59 PM »
I realize this has probably been asked but I could not find it in my search.
My throttle on my 78 550 is not returning all the way closed. I have both cables hooked up and normal use is fine. But my idle is affected, it is hanging higher than if the throttle were properly adjusted. When I push the throttle forward the idle goes down, see video. Is it my return spring? Adjust the pull cable?

'78 550K 2106630

Offline Kevnz

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Re: 550 Throttle return
« Reply #1 on: March 19, 2021, 05:55:13 PM »
Do a search for " hanging idle, I'm done" by Scott S. Sounds like the same or similar issue; finally resolved after much discussion.
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Offline Ichiban 4

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Re: 550 Throttle return
« Reply #2 on: March 19, 2021, 07:34:39 PM »
I realize this has probably been asked but I could not find it in my search.
My throttle on my 78 550 is not returning all the way closed. I have both cables hooked up and normal use is fine. But my idle is affected, it is hanging higher than if the throttle were properly adjusted. When I push the throttle forward the idle goes down, see video. Is it my return spring? Adjust the pull cable?

_________________________________________________________
I have a '77 550K. The OEM throttle return spring was very stiff.  Got tired of holding throttle open on the road..after a while. Others here with same period bikes said the same thing. We replaced the OEM spring with ones that had lighter pull (some stretched-out the length of spring..not as good of a solution)..easier to hold throttle open. Downside to that is that you have to manually close down the throttle @ low speed to get back to regular idle (around 1,000 RPM).

The carb linkage also tends to get stiff after a while..when carbs sit/haven't been cleaned in a while. A shot or two of WD40 on the linkage usually fixes that BTW.

These old bikes worked good when new..but as with anything else..after 40+ years of service..things tend to get 'sticky/creaky' after a while (like us LOL)

Cheers.. Ichi
Al Summers

Present: '77 550K
Past: '73 CB450(twin), '72 CB175, '68 CB350, '58 Ariel Square 4 (1000cc), '58 Matchless Typhoon (650cc single), Whizzer Motorbikes '48 -'55 (Pacemaker & Sportsman)..Vespa, Lambretta scooters..etc.

Offline caluser2000

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Re: 550 Throttle return
« Reply #3 on: March 26, 2021, 10:25:58 PM »
Sounds like the throttle stop screw is in too far
« Last Edit: March 26, 2021, 10:49:44 PM by caluser2000 »
Every time you set your ass on a bike, you're playing a game of Russian Roulette between yourself and your own stupidity."