Anyone ever leave the air screws alone?

[oldgsfan]

OK.. i admit it.. i'm a rookie at carb cleaning.. i dipped 1, 2 and 3 carbs then realized that I really did have an air screw, just hidden under that aluminum plug. I actually began to think I didn't have one. I know. Dumb.


Anyway, this morning I popped the plugs off (what a pain that was).. From the other postings I did see that these air plugs had o-rings so I removed the air plug from the number 1 carb and I found that the o-ring was actually in really good condition.. it was clean, it was very flexible and did not seem to be at all in danger of falling apart.

i have new rings, thanks to Robert Barr, but I'm wondering if anyone has ever done the carb cleaning process and just left these air screws alone.

the other thing was that removing the air screw took some doing.. i mean, i really had to be careful not to damage the screw head, then, putting it back in took some very careful work because it's not like this thing screwed back in easily.. if you'll excuse the language, i had to do some hard screwing to get the thing back down all the way, and seated. then i gave it a turn and half out as per the procedures i've read on the forum.

but i'm wondering if it's just better the leave the other three air screws alone or if I should indeed pull them all out, inspect the o-rings, and go through the whole process with each one.

also, for those of you who have done these carb jobs before, is it always necessary to replace the o-ring on the air screws? Like I said, the one on No. 1 was in good shape so I didn't replace it. But was that a mistake?

Any thoughts, suggestions, comments are much appreciated.

Thanks. Oh, and this is for the CV carbs on a 1980 GS850G.

 

[UncleMike]

Oh yeah, I left them alone for a long time when I first got into restoring/riding these bikes.

And my bikes ran like sh*t for a long time too.

Any job worth doin'...

 

[oldgsfan]

OK.. point taken.

 

[Guest]

what fun would leaving things alone be??

 

[UncleMike]

OK.. point taken.

Hahahahaha. Don't mean to be an ass...

 

[oldgsfan]

Are the air screws supposed to be so snug? When I was unscrewing the one, it was really tight. Not tight as in seized, just that it never loosened up until it was almost all the way out.

I'm just wondering if that's normal.

I never felt like it was ever "lightly seated" when I got back in.. I pretty much had to crank on it to get to the bottom of the hole, then, when it felt like it hit bottom, I gave it a turn and a half out.

Anyway, on to other carbs.

 

[Steve]

Put a few drops of PB Blaster on the head of the screw and let it sit for a day or so. That will help loosen it up and might make it easier to get it out.

Have I ever left them alone? Not since finding out what the improvement was when the carbs were cleaned and ALL the o-rings changed.

By the way, it' not just an "air screw". It is the "idle mixture adjustment screw", as it actually controls how much of a pre-set mixture is admitted to the carb throat, not just air.

.

 

[oldgsfan]

Thank you.. that's a huge help. I have a can of PB Blaster and I'm not afraid to use it..

And, since I have the o-rings, I'll follow everyone's advice and go ahead and swap them out.

 

[oldgsfan]

OK< one more thing if anyone can help me with this.. the carb specs for my bike, an '80 GS850G, say that the pilot screw is "pre-set."

Well, since I removed it during the carb cleaning process, does that mean when I re-install it, all I do is just screw it in til it hits bottom? Or do I need to seat it, then unscrew it a bit for a particular setting?

I was confused by that.

 

[kilog55]

lightly bottom it out then back it off however many turns you are supposed to, my dynojet stage three kit said 4.5 out from lightly seated.

and it is a fuel mixture screw hence the o-ring and yes Mr Barr's kits are awesome he is a great guy for making the kits for all of us.

they are preset that is why they were sealed/covered your not supposed to mess with them for emissions reasons but whatever. juice it up so to speak lol.

you will have to play with it to get it just right, mine is lean but at 4.5 out i can imagine why, just need a good hot day to tune it better

 

[Baatfam]

You'll want to start with them about 2 1/2 turns out. Then adjust from there after it is running....

Good luck.

 

[oldgsfan]

Dang.. I thought I was supposed to do something with them. Guess I'll pop the caps off and set them..Thank you!

Wow. a carb job sure takes a heckuva lot of patience. I think I started my project about two weeks ago.

 

[kilog55]

its a fine game to play thats for sure but when you get it right you will know right off cause it will be so smooth.

any of these bikes need all the rubbers replaced you figure they are from 24 years old up to 30 year or so and most have never been done/

 

[oldgsfan]

by the way, i'm assuming one turn is 360 degrees, right? so, i do that twice, then a 180 degree turn and i've gone 2 and half turns..

 

[kilog55]

yes correct

 

[errorcauser]

Be sure NOT to tighten those to much when lightly seating them. You'll break the tips off the screws, leaving them stuck in your carb.

That's a whole nother night mare there, or it can be, getting those tips out.

 

[Big T]

It helps to take a proper thickness screwdriver, and grind down the edges until it's the proper width for those screws

Otherwise, the tool is too skinny and you're stripping the screw head

 

[pdqford]

By the way, it' not just an "air screw". It is the "idle mixture adjustment screw", as it actually controls how much of a pre-set mixture is admitted to the carb throat, not just air.

Thanks - I have been having a problem following some of these carb threads and how-to pictorials. Seems that some people refer to them as "Air" screws, or "Pilot" screws, or as "Idle Mixture" screws.

Does the terminology change depending on if one is working with a CV carb verses a VM carb? Or is the terminology constant accross the industry?

 

[robertbarr]

Thanks - I have been having a problem following some of these carb threads and how-to pictorials. Seems that some people refer to them as "Air" screws, or "Pilot" screws, or as "Idle Mixture" screws.

Does the terminology change depending on if one is working with a CV carb verses a VM carb? Or is the terminology constant accross the industry?

The terminology (or nomenclature) is so screwed up and arbitrary that I gave up altogether. For the items that need O-rings on the VM's, I named the parts A through F and drew a picture. Find the picture, match the letter, and you're set. http://www.cycleorings.com/VMkit.html

 

[oldgsfan]

OK. to make sure, the air screw that i'm thinking of is the screw on the outside of the body that is covered by the aluminum plug (which, by the way, is a real pain to remove).

the pilot screw, I thought, was on the inside of the carb body where the floats are.

so my earlier question was whether this second screw, that I saw referred to as a pilot screw in the tutorial, whether that one needed to be unscrewed 2 and a half turns after being seated..

as opposed to the air screw, on the outside of the carb body, which, if I'm understanding correctly, should be backed out 1 and a half turns after being seated..

and, by the way, that is a real, real, real big pain.. i'm having a heck of a time getting them out and even getting them back in.. ugh. so far, absolutely the worst part of this carb job has been messing with these air screws..or, i mean, idle mixture screws.