Carb Air/Fuel mix screw....Where?

[RJsfishin]

Still new to me '01 Bike, runs good, but the idle feels like it could use an air/fuel mix adjustment. I don't see one. Is it under a plug that has to be removed ? Could anyone give me the location of the screw/plug ?

[Vegas Street Rider]

I believe it is on the right side of the carb body under a brass cover cap. These thing are set up pretty lean coming from the factory. Turn it all the way in a then back it out around 2.5 turns for starters and then adjust from there as needed. I know there are pictures of the location on the forum but I can't find it at this time. Someone else will probably remember and steer you in the right direction.

[blaine]

I believe it is on the right side of the carb body under a brass cover cap. These thing are set up pretty lean coming from the factory. Turn it all the way in a then back it out around 2.5 turns for starters and then adjust from there as needed. I know there are pictures of the location on the forum but I can't find it at this time. Someone else will probably remember and steer you in the right direction.
Yep....In front of the float bowl.

[RJsfishin]

Yep....In front of the float bowl.

If I'm looking at the correct brass plug, is it installed from bottom to top, making the idle mix screw in a vertical position rather than horizontal like most ?
And am I correct in concluding that removing the carb would be the best way to remove the plug ?

I did this once before on a previous s-40 650,.....looks like the same plug, only it was in plain view and horizontal, and easy to remove.

Rich

[derbydave]

Yes the pilot jet is installed vertically. I don't think you could get the plug out without taking the carb off. I had mine on the bench when I serviced the pilot circuit.

[Vegas Street Rider]

You might want to download the GZ 250 service manual. It has a pretty good breakdown of the fuel system with pictures. Hope that helps you.

[RJsfishin]

Thanks guys !

[RJsfishin]

Yes the pilot jet is installed vertically. I don't think you could get the plug out without taking the carb off. I had mine on the bench when I serviced the pilot circuit.
Dave.
I have the carb off. I started drilling the the smaller plug, the one that is in the long boss hanging down. But it doesn't look like brass. I see a larger brass plug behind this one, but up higher, both being in front of the bowl.
Is this larger brass plug for sure the one that will uncover the air/fuel mix screw ?
Rich

[derbydave]

The plug covering the pilot is about 1/4 -3/8 inch in diameter. See Attached Photo. I have it circled. You only want to drill the plug enough that you can thread in a screw enough to use as a handle to pull the plug out. Drill too far and you risk damaging the jet or carb body.

[RJsfishin]

The plug covering the pilot is about 1/4 -3/8 inch in diameter. See Attached Photo. I have it circled. You only want to drill the plug enough that you can thread in a screw enough to use as a handle to pull the plug out. Drill too far and you risk damaging the jet or carb body.
Thanks Dave
I got the plug out before you had gotten back to me. I made a sure location by following the hole in the venturi. And it was the one that I started to drill, the one in the boss that hangs down, which is the one that you have circled in the photo.
Let me add my bit of info to this thread, in that it is NOT a brass plug. There is a brass plug just behind this one. The plug is exactly 1/4" dia. The brass plug behind it, looks to be all of 3/8" dia. Is it possible that some of the correct 1/4" plugs are brass. Or I would wonder how many have drilled out the wrong plug.
Anyway, this job turned out perfect.....thanks Dave.....and others.

[derbydave]

Glad to hear you got it fixed. I wonder if the plug in your carb was replaced at some point. All of them I have seen are brass including the one I drilled out of mine.