The Briggs and Stratton Pulsa Jet carburetor regulates fuel flow on the aluminum series of engines. The most common application of this carburetor is for small horsepower lawn mowers and rototillers. The Pulsa Jet carburetor resides above the on-board gasoline tank. Fuel is drawn up into the device through two fuel suction lines. A single needle valve resides near the rear of the carburetor unit, that faces the push handles of the mower or rototiller. The needle valve has a slot-type screw head.
Close the needle valve with the screwdriver in a clockwise direction.
Open the needle valve 1 1/2 turns in a counter-clockwise direction. This setting allows the engine to be started and warmed to operation temperature. Keep the air filter in place for correct adjustment.
Start the engine according to the manufacturer's instructions for the device. Accelerate the engine to operational speed.
Turn the needle valve in a clockwise direction, closing it, until the engine begins to lose speed. Slowly back the needle valve out, counter-clockwise direction, until the engine smooths out.
Test the engine under a full-load condition. Mow grass with the lawn mower or cultivate soil with the rototiller. Turn the needle valve slightly in a counter-clockwise direction if the engine loses speed while under full-load conditions. It may take several minor adjustments to the needle valve in order to get the best performance from the engine.