I have a Sachs 505/D on my 79' G3. It is having trouble idling. I've done all the basic stuff: messed with the idle screw, sprayed for air leaks, adjusted the throttle cable, tried a completely different carb off of a working ped, tried it with and w/out the air filter housing, etc.
I'm going to upjet as well because I think the exhaust on the ped is not stock. It is way too loud to be stock so maybe it's been modified internally (no idea what previous owner did to it). I am also going to adjust the clutch because it's not catching correctly.
The strangest thing of all however is that when the motor is running (when hold the throttle) air is actually blowing out of the air filter housing! I would assume it should be sucking in?