Re: Carter WGD 728S help needed

Posted by BH On 2013/5/2 21:04:45
Also when driving along, it feel like the engine is running a little rough. When playing with the carb in the driveway, if I close the choke slightly when holding the throttle open for what sounds like about 1500 rpm, the engine smooths out.

I have to wonder if you've got a vacuum leak somewhere. Instead of diddling the choke butterfly, take a trigger spray bottle filled with plain old water and squirt around the gaskets - especially the throttle body - and see what, if anything, changes. No change? Then start plugging vacuum ports.

Also, I am having a hard time getting the choke to work correctly. It caused the engine to run so rich on me today that it stalled in traffic. Just to make sure it was open, I turned the spring until it held the butterfly valve open.

The thermostatic choke spring is supposed to close the butterfly valve, when the engine is cold - not hold it open. Is the spring installed backwards in the cover? A vacuum-operated piston helps open the valve - another reason to check for vacuum leaks (first).

BTW, did you check the archive Carter Carburetor Service Sheets? There's a set of sheets specific to the 728S and 728SA, and they include detailed instructions for adjusting the float, accelerator pump, metering rod, fast udle, and choke unloader.

While there's nothing in the 46-50 Shop Manual on carb overhaul, the 48-50 Service Index - namely, the FUEL & EXHAUST section - shows an article on service overhaul and adjustment of the the WGD 728S (new for 49) in SC Vol. 23, No. 11. You might also wanna take a look at STB 49T-41, Dealer 31.

This Post was from: