Packard Forum Index » Post-War (1946-54)

I have rebuilt my carb (Carter WGD 728S) on my 49 Deluxe 8, 288 engine. It was running rich, and who ever had it apart before me used high temp silicone on the gaskets. What a mess. I feel that there is a slight hesitation when accelerating lightly. 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 think it might be running a bit lean. Any suggestions as to how I might correct this as there is no adjustment screws for other than idle mixture. 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. I just haven't got something right with it. Looking for suggestions here also. Thanks for the help.

I'd suggest you recheck the fuel level (float adjustment); the idle mixture screws are only for mixture when running with the throttle plates closed. But I'd resolve the choke issues first.

Just a note for those that aren't aware, carburetor gaskets are installed dry, no gasket paste or cememt, and NEVER use silicone gasket cement on anything associated with gasoline,

Quote:
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.

Quote:
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.

U indicated a RECENT carb rebuild???? IF the needle and seat that came with the kit had a "rubber" tip AND it has been more than 6 months since rebuild then it is possible that the ethonol in the gasoline has swollen the rubber tipped needle and causing a low float level.

Vacuum leaks can cause your symptoms too.

How did the engine run BEFORE the rebuild???

The rebuild is only a couple of weeks old. Float level was bang on acording to the sheet I got with the kit. Before the rebuilt it was running rich. I have looked to eliminate vacuum leaks, but did not try the water spray. Also what makes me think its running lean is the temperature gauge. But to that point, the weather is warmer than what I have run it in, and it just may be the way it reads. As far as the silicone, I could believe that it was a mechanic that did that. It had turned gooey and was everywhere.

EDIT: Tried the water spray all around the carb, did not notice any change. So when I have a chance, I am going to pull the carb off and increase the level of gas that's in the bowl to see if that helps. Thanks for all the suggestions. I'm also going to have another look at the service info.

Delux,

Did you check the metering rod height with a metering rod gauge? I can't recall which gauge number off of the top of my head. If the rod heigh is mis-adjusted you could be running rich.

I have tried many sources and old-timers and have had no luck finding a gauge. If anyone has one, I'd be interested a tracing of it. So to fabricate one. I have a gauge of a different size.

Here is a picture:

http://www.cj3a.info/tech/meter.html

Also-Didn't the 22nd-23rd 288 & 327's come with Carter WDO's? Would a WGD run richer with different jets in it?

Good luck!

Mark

WGD 728S could be correct for a 23rd series Eight and Deluxe Eight; I believe it was a running change and the WGD was used after motor # H238000.

On the WGDs it is easy to check the metering rods, no gage needed:

I started to try to describe it, but it is in the manuals and only take a couple of minutes. Make sure the pump operating link is adjusted OK (operating lever level) before you begin.

D-train - I haven't checked the metering rods, but I don't believe that it is running rich. I believe that it's running lean due to an increase in my operating temperature. As a test, in the driveway I opened the throttle to what sounded like about 1500 RPM to me and the engine was not running smoothly, and jiggling excessively. I slowly closed the choke butterfly and the engine started running very nice and smooth. No miss and it stopped jiggling.

Thanks to all who jumped in with suggestions. This is my first rebuild of an automobile carburetor. I checked the set up for the metering rods. Seemed to be correct. I jumped the starter solenoid to crank the engine over without ignition to make sure the bowl was full. Pulled the top of the carb and the gas was barely over the metering rod holes (jets?). So I checked the float level a little more accurately than before and it appeared to be low. So I tweeked it and reassembled the carb and started the engine. Oh so close. Did the same thing as before, opened the throttle for some good rpm. Engine jiggled slightly. Nothing like it did before. Slowly closed the choke, and it smoothened right out. So I need to tweek it just a hair more and should be good. Thanks again!