Currently trying to figure out why this 108 runs so poorly. I have no history of the car other than it sitting for many years. Ive rebuilt the carbs and found that one choke does not work. Currently trying to dial it in with the chokes backed off all the way both front and rear when warm. The fuel return valve is also missing and was replaced with a normal banjo bolt. Not sure if this will affect the way it runs as both float bowls seem to always be full when checked. Valves have been adjusted and timing set to tdc at idle. I seem to be having a problem adjusting the butterflies to match each other, I get close but it just doesn't seem correct.

My question is:

Im getting a draw from both front and rear secondaries at idle, is this normal for these carburetors?

Upon slight movement of the throttle in gear, I get a flat spot. The accelerator pumps both work great, but not with the initial tap of the throttle. It looks to me as the linkage may either be worn, or needs adjustment. It works great if you throttle 1/4 to full. Should I attempt to bend the arm to have it work immediately with a touch of throttle?

Its my understanding through research online that these cars are set tdc at idle for timing. Is this correct?

The dashpot seems to be giving me hard time. It isn't leaking but it just isn't kicking up the idle like it should in gear. I have a feeling that vacuum isn't changing as much as it should in park or in gear.

Thanks for reading my long post. And I appreciate it greatly if anyone has any information that may help me out. The car is a 1968 mercedes 280s if it makes a difference. Thanks for the wealth of information!