How accurate does carb air screw have to be?

[markdjr]

I have a 78 GS550, it's my first bike so I am still figuring this stuff out. I was trying to adjust my idle up a little and accidently adjusted one of the air screws on one of the carbs. I am not sure I adjusted it back exactly as it was (Maybe a full turn off). How accurate should this be? Am I damaging anything riding it if it isn't correct? Thanks.

[don_gibb6512]

All the air screws should be set the same. Start turning in (gently) one of the other screws until it stops and count the turns then back it out exactly the same. That's all there is to it.

[chuckycheese]

Close

Even though carbs looks just alike, there are almost always subtle differences because of the complexity involved. If the bike runs well and the plugs all look good, you've got it right. If one of them is adjusted incorrectly, it will run crummy but it won't hurt anything (other than the fact that you won't smile as much as you go down the road). I agree with Don that when you get it adjusted correctly, it will be nearly the same as the others; just not necessarily exactly the same.

[jimfj]

I have used sevral different methods on my 850G to adjust the carb air/fuel screws and you will find that, even with the help of a Colortune, nothing will be exact. Basically you get them as close as possible and then do your carb sync. I believe that the sync. accuracy is more imporant/benificial than the fuel/air adjustment.

Please understand: 1/4 turn on the fuel screw isn't half as sensitive as 1/4 turn on the synch screws.

Remember also: The screws on my 850"s carbs control the amount of fuel and air going into the cylinder, not just the fuel.

I hope this helps and to answer the question of damage, no. I rode my bike home from the P.O.'s on 3 cylinders and the carbs were so full of gunk that it suprised me it even ran at all. That saying that goes "The Suzuki GS will always get you home", is true

Jim

[doctorgonzo]

Adjust as others have said, starting from a baseline with them all set the same (factory spec), then tweak from there.

[renobruce]

If you are talking about the side air screws (the VM carbs have two adjustments), set them to run at the highest RPM. They should all be close to the same... within about 1/4 turn.

[Suzuki mad]

What I have found out about carbs lately is that if they have any parts inside that are faulty you can get around it buy synicing the carbs to make it run smooth.

The air screws are all set to a factory preset which is a given number of turns out from seated as every one has said. If you have an ear for engine you can adjust these slowly and listen to the engine speed up or slow down for the optimum performance.

Its not going to harm to much if one is slightly out. Run it a little and then have a look at the plugs. If the one you know is wrong try and give it a 1/4 turn more or less and see how that runs till you get them all about the same.

Suzuki mad