Why Does The New Carburetor On My Lawn Tractor Now Surge And Pulse?

What causes a carbureted engine to surge?

If an engine is not getting enough fuel (this is called “running lean”), due to fuel pressure (regulated by the fuel pump and regulator), restricted fuel injectors, a vacuum leak or really anything that throws off the fuel mixture going in to the engine, this can cause the surge.

What causes lawn mower engine to pulsate?

This vent is just large enough to allow air into the tank, creating enough backpressure to aid in fuel delivery to the carburetor. Surging is also caused by water that got into the fuel. A mower left in a heavy rain or condensation on a hot summer day can choke the engine.

Why is my Briggs and Stratton surging?

The most common reason for a surging lawn mower engine is a blockage in the fuel supply, but there are other possibilities: Bad gas. Bad spark plug. Dirty / faulty carburetor.

Can spark plugs cause surging?

3. Surging and Lagging. Another good indication that your spark plugs are dirty or worn is if your vehicle experiences surges of speed, resulting in a jerking acceleration. These surges occur because your spark plugs are not igniting the fuel in your engine at the proper rate, resulting in an uneven speed.

Why does my riding mower rev up and down?

A lawnmower that hunts and surges may be experiencing something as simple as an airflow issue. If the air that the engine requires to run is blocked, especially sporadically, it can cause the engine to slow down. When the blockage moves or clears, the engine may suddenly rev up in response.

What does engine surging mean?

Engine surging is different from a difficult start or a no-start problem. “ Surging ” does not refer to a knocking engine or one that idles rough or stalls. Engine surging is when an engine starts easily and accelerates smoothly, however after a few minutes at a steady speed, it either surges in speed or misfires.

What causes a Kohler engine to surge?

Surging on small engines is very often caused by a lean condition. Since the carb is new, any leanness is likely due to a vacuum leak somewhere.

Why is my riding mower sputtering?

Your mower pulls in air from outside and mixes it with gasoline for the proper explosion inside the engine. A dirty air filter inhibits the flow of air into the carburetor. Clean or replace the air filter to stop the mower from sputtering to a halt. Too much air can also cause problems for the engine.

What causes an engine to hunt and surge?

Engine hunting and surging at idle is usually caused by a fuel delivery, air leak, or governor system problem. Cleaning/overhauling the carburettor, adjustment of the governor, and/or changing the air filer may be required.

How do you adjust a Briggs and Stratton carburetor?

Locate the idle adjustment screw on the side of the carburetor. It sometimes has a spring wound around the shaft. Turn this screw clockwise with a Phillips screwdriver until you encounter resistance, which means it has contacted the carburetor seat. Back it off 1 to 1 1/2 turns.

How do you adjust the governor on a Briggs and Stratton engine?

To adjust the governor, you would loosen the screw on the bottom of the governor arm and push the governor arm so the throttle is wide open. Then you would turn the bottom “clip” (which is connected to the governor shaft) counter clockwise. This will set the governor shaft on top of the governor spool.

Why is my lawn mower not running smoothly?

If the engine starts, but does not run smoothly, it means that the spark plug and ignition system are in order and you need to look elsewhere for the source of the problem. The usual culprit is air intake or fuel system related.