A log splitter uses a gasoline-powered engine connected to a hydraulic pump. The pump compresses fluid under pressure until the pump piston is released with sufficient force to split a wood log. Many log splitters are equipped with an adjustable pump to increase pressure for greater efficiency when necessary. For example, it may be useful to increase pump pressure in cold weather or when splitting various species of wood with varying densities. Adjusting the pump takes only a minute to do.
Start the engine on your log splitter as you normally would. Some models have a pull cord, and others use a keyed ignition system. Let the engine reach idling speed to allow time for the hydraulic fluid in the pump to warm up.
Set the pump lever in the neutral position. Keep your hands clear of all moving parts, especially the splitter wedge in front of the piston and pump.
Twist the screw on the side of the pump clockwise with a flat blade screwdriver to increase pressure, according to the scale printed or embossed on the side. Turning the screw counterclockwise decreases pump pressure.
Raise the guards on the sides and back of the splitter to the upright locked position. The equipment is now ready to operate normally.