Quote:Carb Will Not Idle Down
Sometimes the carb will not idle at lower than 1000 or 1200 rpms. This is almost always a mechanical problem, but the possibilities include:

1.Throttle cable is stiff or incorrectly adjusted. Leave this cable loose until the carb is completely adjusted, THEN tighten the two nuts with 7/16" wrenches.
2.The cam within the automatic choke is not returning to a "full off" position, sometimes caused by a melted plastic plunger on the bottomside of the unit. Melted? Remember that cherry red hot catalytic converter? Sometimes the levers are bent. They all work on nice, sharp, 90 degree angles.
3.The overrun valve is floating open at a very low manifold depression. The spring loaded valve on the throttle disc is designed to open only at extreme manifold vacuum -- deceleration. If there has been a fire within the carburetor, the spring may have lost its force. The valve is easily soldered shut obviating any further problem (and increasing throttle deceleration response). Heat the valve from the button side with a propane torch and flow solder into the valve from the spring side. The Midget overrun valve can be completely shut off by fully unscrewing the small slotted screw on the triangular shaped device on the right side of the carb.