Thanks for the suggestions and help. Decided today to go back to step one, taking off the Solex to see what is what. It is easier this way to check all the vacuum connections off the carb.

All connections are solid into each oriface and all interconnections are good as well. Did find a mistake in the vacuum booster connection where one line was attached to the wrong port. The Solex I'm working with has no "D" connection drilled in the cover which goes to the vacuum booster. Going to have it drilled and piped due to the Secondary butterflies are sticking at full open. Hopefully the shaft can be rebushed, polished to cure the sticking full open condition.

To my surprise when taking off the carb a pool of fuel was found in the intake. Now I am really puzzled! The float level is adjusted correctly, but why the pooling of fuel? Going back to the engine manual, reading each page, I'm starting to think it is the fuel return valve is not limiting the pressure or the float chamber valve is not working correctly not allowing the float to equalize pressure causing the overflow. Dunno, any suggestions would be appreciated. By-the-way, if anyone knows what group the float chamber diaphram belong to, please let me know. Called two MB dealerships and both could not find what I was talking about. Think the 280S is older than both of the dude's I talked to as they acted as it I was trying to sell them some muffler bearing grease. :-)

On the last rebuild, I did not replace the bottom gasket, or insulator gasket which is between the Solex and intake manifold. This is suspect was causing the vacuum leak, knock on wood.

Also engergized both fuel cut offs and both are retracting fully. That is one thing to rule out. Have also checked the fuse for each and neither have blown.

Well, now I'm up to getting the Secondary shafts refurbished and if I can find it a diaphram for the float chamber valve. Any suggestions would be greatly appreciated and do thank you for your help so far. Want to sell this car and get a Stick 300E like ctaylor738 has ;-) .

Gympie