Carb has 1 screw, Fuel Pump??
 

My carb has only ! adjustment screw,didn't help my problem. It still won't stay running. When you turn the ignition on the fuel pump should start mine doesn't. Do I have an electric problem? Thanks

The screw is air/fuel mixture.

Turn the key to the "on' postion.Listen and feel for the fuel pump on the drivers side by the rear tire behind a metal plate.

If that dont come on or your nto sure,Turn the key off,disconnect the fuel hoses going to the carb,have soe one put the key on the on position,and have a container,just incase the fuel starts pumping,If that dont work ,check fuses and wires down by fuel pump it might be bad,

If its ok and the carb wont stay running ,the carb may have bad floats,or the plugs may have bad carbon on them and not goetting good spark.