Re: WGD carburator with a mind of its own

Posted by Owen_Dyneto On 2011/1/28 12:51:22

JW's advice is spot-on, as usual. However, when you say you rebuilt the carburetor, I'm wondering if you removed or loosened the screws that hold the throttle plates to the throttle shaft? They must fit very precisely, and they are not symetrical so they could possibly be installed incorrectly. The edges are precision ground at an angle to form a tight fit in the bore when the throttle shaft closes. Should they not close tightly, you will be unable to obtain a proper idle mixture setting.

Also, make sure you have no vacuum leaks elsewhere; intake manifold gasket, vacuum booster portion of the fuel pump, wiper or washer motor, etc.

Though it doesn't take much practice to set the idle mixtures by ear as JW describes, many folks like to use a vacuum gauge. Attach it to the intake manifold, BUT NOT so that the booster pump can interfere with the reading. Then run each idle screw individually in until the engine falters, and then screw it out until maximum engine vacuum is obtained (18+ inches and rock-steady for an engine in good condition).