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Discussion Starter #1
Alright, after ditching the idea of setting my idle speed with the use of tools, :p I went ahead and just "eared" it this evening - seems fine, and is around 1200 rpm. Good to go. But, while doing that, I remembered (now that it's getting cool out) that I've been having trouble with my choke, and want to see if anyone has an idea as to what's happening.

When I close the choke, with the lever between 1/4 to 3/4 closed (i.e., towards me), the engine stumbles...then regains momentum and the rpms increase. I took the slack out of the cable this evening, and am just getting the stumble/delay/rev at the 1/4 setting. The cable is connected to...what, the choke valve? With that also about 1/4 of the way out of the carb, the stumble is happening, ergo it's not just a cable issue.

Am I supposed to do something with the throttle cables when I also adjust the choke?
 

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All you should need to do is just take the slack out of the cables. The bike was running OK before yes,no other If it was then this is OK all you did was bring it closer together. Only if the bike was running fine before...........
 

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NO CLUE here... but I would be interested in the answer to this one...
 

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Discussion Starter #4
Yep, the bike's running fine. I'd just noticed on cooler mornings over the summer that when I closed the choke, the idle would stumble and sometimes the engine would die. On those a.m.s, I'd just keep the throttle open a little until the bike warmed up some, and then was able to get the choke closed enough (without the stumble) to get the bike all the way warmed up.

So the stumbling thing was going on before I adjusted the cable this evening. I just thought that that would fix the problem, but there's still a little hitch in the girl's gittyup.
 

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Mine is great too, at full choke revs fine, when I start to close the choke, at about 1/4 on it starts the stumbling... I wait at this point for the engine to warm up, or I just start out riding and then push it closed while I am riding. It isn't like it's causing problems, just annoying.
 

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kait said:
Mine is great too, at full choke revs fine, when I start to close the choke, at about 1/4 on it starts the stumbling... I wait at this point for the engine to warm up, or I just start out riding and then push it closed while I am riding. It isn't like it's causing problems, just annoying.
Sounds about normal.
 

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It sounds like either the idle adjust or carb sync may be the problem, It seems with choke, the bike is going too rich. The choke is actually not a choke, it is an "enrichener" allowing more fuel to enter the airstream.

Just a guess mind you......
 

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same issue here. I can only use less then 3/4 choke on cool days (75 degs or less) and on cold days (less then 55) i use full to 3/4 to start with and after a few moments i switch to less then 3/4, just kinda ear it, untill i think she is warm.
 

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Hmm, sounds like you all have been spoiled by your fancy computer controlled easy starting new fangled "fuel injection". :)

Seriously though...what your describing is just normal for a cold carburated engine. My 78 olds did what you describe...so did my 84 RX7, 85 Dodge Pickup, 88 Kawasaki EX500. And my Vulcan does it too.

If it runs fine once it warms up, there is nothing wrong.
 

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I never start moving until I shut my choke off, so I can't say how mine reacts. I know my old bikes wouldn't be friendly until they were warmed up - meaning that you couldn't do any hard accelerating until the bike was warm enough to run with the choke off.
 

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and the Adventure Cycle
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Imnohero said:
My 78 olds did what you describe...so did my 84 RX7,
What kind of Olds ?? I gotta a 78 Delta 88. Love the big old boats !!
And the RX7, :smiley_th I'd love to have one of them !! The old body style, NOT the newer ones ! And NOT red !

And, in keeping with the topic at hand....
The way I understand your description of what happens, it sounds just like the way mine runs when starting cold. I'd say you got nothing to worry about. Ya took up the slack in the cable, you're good to go !
 

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Discussion Starter #12
Got the idle adjusted ok, but haven't done the carb sync thing yet (every time I say "manometer," I have a Muppet's show skit in my head..). It's not making sense to me that since the choke cuts off air flow/enriches fuel flow, that it should actually cause the engine to stumble when the engine's idling and I'm closing the choke...but since you guys are saying "it's normal," then I'll consider that taking the slack out of the cable was sufficient and just go easy on closing down the choke this fall.

Next on the hit parade: Manometer ("da dahhhh da-da da"). :pepper:
 

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Da da dada, da da dadada, da da dada, da da da dada da !!

Well, I can't quite sing the tune like on 'The Muppets' !! LOL
But I know the one you mean Cindy. :rockon:
 

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Discussion Starter #14
I know the song all too well. Sadly, once it gets into your head, it'll be there awhile. What the Germans call an "ear worm." :BLAM:
 

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When I say "Idle adjust", what I meant was the screws that adjust the mixture on each carb....The ones' that have a cover on them so you can't adjust them unless you remove the plug. I know mine needed adjustment badly, now I have great idle and full use of the choke. Although riding with the choke on is probably not a good idea, the engine is running too rich.
 

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and the Adventure Cycle
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Imnohero said:
Had a 78 olds Delta 88 2 door. Metalic blue with a sky blue interior. 350 engine with the Rochester Quadrajet Carb.
Well, ya got me there. Mine's a 4 door. Sounds like same engine & color interior, but was a faded out sky blue exterior. Would've rather had the 2 door, but the $100 price tag, and more than a few years of use were well worth it !
 

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it's all goes to the fact that at lower temperature it's harder for fuel to mix with air and atomize. instead it just condenses on cold carb walls untill the engine warmes up.

i engage the choke about 3/4, start the engine, move choke to full. from there i just try to open choke gradually to keep about 2k rpm. while the ngine warms up i have time to lace boots, zip everything up, put helmet, gloves etc. however i never start moving before the choke is fully open (handle away)

never adjusted the choke cable so cant help you there...
 

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My routine is about the same as tankist. I keep the rpm around 12-1500 rpm. When I'm ready I ride the 100 yards to a state highway. As I pull onto the highway I flip the choke wide open. Done deal.
 

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Discussion Starter #20
Well, that may be part of my problem - I'm starting the engine, deciding the idle is off, and then closing down the choke. Probably should close it at whatever position before I hit the ignition switch.

dta116 - how the heck did you pull the plugs out from the fuel/air adjust screws? I know folks say, "Use a drill - carefully," but I can't fit one in there. Or at least I don't think I can. Is there a trick I don't know about?
 
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