I always remove spark plugs one at a time and pour some fluid into the cylinders and repeat that for about a week or two. Pouring in an ounce or so at a dose. Then I turned them over on a bar or with ratchet with peice of long pipe over it for leverage. I usually install new plugs or at least clean the ones there. I usually pull the carb and clean/go through it and install new gaskets under it. And, I always pull the fuel line and when trying to crank run from a clean jug of fresh fuel through the fuel pump. Depending on how it runs I might install new points/condensor/plug wires and so forth later.
