74 450SL- I would recommend that you not try to start the car until the entire fuel system has been drained and thoroughly cleaned and new fresh fuel is added. Gasoline will turn into varnish after sitting for a while and this varnish will really gum up your fuel system. If you plan to operate the car sporadically, add Sta-Bil to the fuel system. Sta-Bil will prevent the gas from turning into varnish.