Mercedes Benz repair: runs rough when started with warm motor, camp test, sl mercedes

Question
I have 1976 350 sl Mercedes in good condition it uses no oil and performs well when started from cold it turns over a few times then starts and runs perfect when started hot it starts perfect but when left for a short time say 20 minets it starts rough and takes approx 30 seconds to run on all 8 cylinders

Answer
sounds like you may have misfiring upon a higher load , when was the last time you did a tumeup plugs wires cap rotor?I would start there if you have recently replacd all items when did you last time the engine??I would then maybe take a camp test on all cylinders to make sure they are within specs to make sure you are getting good compression..