Ok i bought a 87 tintop sammy that has been sitting for along time. i did all tune up stuff plugs wires brakes shocks and whatnot anyways when i start it it will run but lacks power and kinda sputters. after about 10 minutes of run it will loose power and dye. try to start it right away and it just cranks. let it set for like 5 mins starts but barley runs. let it set like 10-15 mins and it starts right up and runs for like 5 mins b4 doing it all over again. i am a efi guy so i have no idea is this a carb problem? any help would be gr8 thanks

did you change your fuel filter as well? also try some seafoam in the gas that will help clean up the carb better then anything i know of short of rebuilding it.

Did you change the battery? That may be affecting the ignition and cause it to not turn over.