I don't know if this trick has been documented anywhere, but a fellow could simulate a decompression system by jamming the intake valves in the open position, cranking the engine over, then removing the jammer from under the rocker arm. A piece of shim stock or feeler gauge could be used to jam the intake valve in the down position. I am not sure of the necessary thickness, but it would have to be enough to lower the cylinder compression without exposing the valve face to being struck by the upcoming piston top. Perhaps 10 thousands up to a tenth of an inch in thickness. This decompression trick would allow a near dead battery to crank the engine over fast enough to get it started. Things that would help. Heat the air intake. Heat the engine, generally, the coolant particularly. The jammers should be removed one at a time, hopefully as each just compressing cylinders starts firing. In other words, let a cylinder get to firing before removing the next jammer. The jammers should be placed over the valve stem, not on the face of the camshaft. Mike Capt. Mike Maurice Tualatin(Portland), Oregon