Re: WGD carburator with a mind of its own

Posted by JWL On 2011/1/28 12:16:49

The two screws you refer to are for the idle mixture jets. They increase or decrease the amount of fuel mixed with air for the engine at idle speed. Turning the screws in reduces the fuel, and turning them out increases the fuel. If the engine runs with the screws turned all the way in, the carburetor is providing enough fuel for the engine to run without using the idle mixture circuit. Either the float setting is too high or the needle and seat inlet valve is leaking. There is an idle speed adjustment screw too.

Usually, the starting place to set the engine idle is to have the idle mixture screws turned out one or one and one-half turns from where they bottom when screwed in all the way, and with the idle speed screw making contact with its stop on the linkage.

After the engine is running and warm the idle speed is set. With the idle speed adjustment at the specified speed, the mixture screws are turned in until the engine starts to slow then screwed out until it is smooth (usually one-half turn). You will need to go back and forth with the idle mixture screws and the speed adjustment to achieve the correct idle speed, ending up with the idle mixture screws. Both idle mixture screws should adjusted be about the same.

The choke plate should be fully released when the engine is warm. It should be just closed on a cold engine.

Of course, all of this is dependent upon the distributor points and ignition timing being adjusted correctly.

I hope this helps, good luck.

(o{I}o)