adjusting my fa50 carb???

recently i took my carb off my 1980 fa 50 for cleaning, i counted the turns of the adjustment screws i took out and i put them in exactly how they came out, although the bike has been sitting for 20 years so im not sure if the settings will still be wanting to know if someone can provide me with a diagram of the carb and what each adjustment screw does so i can tweak them as needed once i get it running


Re: adjusting my fa50 carb???

Try this link for the picture,

The screw closest to the air intake is for mix, #20 on the diagram. The screw on mine is a Phillips head. The other screw is Slotted and is for idle. It lines up with the throttle cable. I have mine about 1 3/4 backed out. 1 1/2 is a good starting point. I am not a FA50 expert but in the 3 weeks I have been working on mine my skill level has sky-rocketed!

Good luck,

Re: adjusting my fa50 carb???

TRy 11/4 turns of the air screw to start with. The idle adjust screw should be turned initially tot lower the throttle slide all the way down so it bottoms out, the turn the screw in the other direction until it just starts to raise up. This should be a good starting point. Once you start the engine and let it warm up, you can readjust the idle screw to the proper rpm. Then there is further adjustment of the air screw.

Re: adjusting my fa50 carb???

i know the 2 screws your speaking of, and thatks a lot for the replies, but do either of you know which screw controls the idle and which controls the mix?...there is a bigger one and a smaller one

thanks soo much

Re: adjusting my fa50 carb???

The idle screw is the one that is more centrally located ie. it is at the base of the large vertical throttle tube. Basically, it is a screw that contacts the base of the throttle slide at a point where when you turn the screw, it pushes the throttle slide up or allows it to lower depending on which way you turn the screw. turning the screw clockwise makes the screw go in and, thus pushes the throttle slide up (increasing idle speed). If you turn the screw counterclockwise, the screw backs out and allows the spring-loaded throttle slide to be pushed down, thus closing off the air/fuel opening and reducing idle speed. The air mix screw is closer to the air filter end of the carb. Or, here's the easiest explanation of all. When you look at the carb wheree the two screws are, the idle screw is on the left anad the air screw is on the right!

Re: adjusting my fa50 carb???

I guess I need to sign up for a writing course..... I did not make it clear enough in my earlier post! Maybe I can ride my kids FA50 to class.......... HA

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