Where to set idle speed screw after carb rebuild for 1st start? Rule of thumb?

[Guest]

So I'm cleaning/rebuilding the BS34SS carbs on my newly-acquired 81 GS1100E. I didn't think to make note of the position of the idle speed screw (X turns out, etc) before teardown and cleaning, and I know I've adjusted it in an out while cleaning and lubing the mechanism, doing a "bench sync" etc and it is probably very far from where it started. I'm wondering if there is a rule of thumb as far as idle speed screw setting that will get me within a reasonable range to allow it to start up for the first time?

 

[Guest]

Easiest while still on the bench, but back the screw out until it does not touch, then go back in until it touches, then two full turns more

 

[Dogma]

Run it in until it bottoms out, gently. then back it out 3 full turns. That should be plenty rich enough to start.

 

[Guest]

Run it in until it bottoms out, gently. then back it out 3 full turns. That should be plenty rich enough to start.

Is he asking about the idle MIXTURE screw (which should be turned out 3 turns) or the idle SPEED screw, as mentioned in the thread title?

 

[Guest]

Is he asking about the idle MIXTURE screw (which should be turned out 3 turns) or the idle SPEED screw, as mentioned in the thread title?

To clarify, I am looking for where to set the idle SPEED screw. The one large thumbscrew that controls idle setting for all carbs at once. I set the idle mixture screws on each carb to 2 turns out from lightly seated. The rule of thumb I heard was to start at 2.5 turns out and dial it in from there, but I live at basically sea level, and the carbs have one-size-higher pilot fuel jets than spec in there for some reason, so figure starting out with the idle mixture screws in (leaner) a tad bit is probably not a bad idea to start. Of course will dial those in once back on the bike. In this thread I'm looking for where to set the idle SPEED screw to give me a fair shot at actually getting the bike to fire and turn over. Just have nightmare of going to start the bike and it won't catch and then trying ti figure out which part of the rebuild I screwed up or which adjustment is off. Having a reasonable "probably close enough to get you running" setting for the idle SPEED screw will hopefully help avoid that I think I'll be following Phydeauxmutt's advice for now and see how it goes!

BTW Phydeaux - you hail from cajun country? I have kin all over south LA, two of my (male) cousins are named Rene and Boyeaux, and their dog growin up was named Phydeaux (a catahoula, naturally). Anyways. seeing your name gave me a little chuckle this AM

 

[Who Dat?]

In this thread I'm looking for where to set the idle SPEED screw to give me a fair shot at actually getting the bike to fire and turn over. /QUOTE]
Phydeauxmutt answered that in post #2.

 

[Dogma]

Is he asking about the idle MIXTURE screw (which should be turned out 3 turns) or the idle SPEED screw, as mentioned in the thread title?

Glossed right over that...

 

[Guest]

In this thread I'm looking for where to set the idle SPEED screw to give me a fair shot at actually getting the bike to fire and turn over. /QUOTE]
Phydeauxmutt answered that in post #2.

Yup, which is why I said the following at the end of the very post you quoted:

I think I'll be following Phydeauxmutt's advice for now and see how it goes!

Thank you for pointing his answer though, sometimes it's easy to miss specific posts (or comments within one). As it turns out his advice was just the ticket. Bike started up almost instantly after just kissing the starter button. Not sure exactly where idle speed screw ended up relative to starting position after I got the carbs dialed in (lots of tweaking isle speed back and forth as I dialed in the idle mixture screws etc) but his advice of two full turns in after it first touches got me right in the ballpark for an initial start.

 

[rphillips]

Uh, are you sure? "two full turns in after after it first touches", that would seem pretty darn tight...RocketScientist???

 

[Who Dat?]

Uh, are you sure? "two full turns in after after it first touches", that would seem pretty darn tight...RocketScientist???

RP, keep in mind that it's the idle SPEED screw, the one UNDER the carbs, not the MIXTURE screw.

The idle SPEED screw can be turned MANY times after it first contacts the linkage. Anything much more than two turns will send the tach needle WELL into the red zone.

 

[Rich82GS750TZ]

Because this thread is confusing a few people, a pic to clarify. This is the Idle speed adjustment screw to which the OP is referring.