Why does my Briggs and Stratton engine surge?

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.

What causes small engine lope?

Problems in the Fuel System Check and clean the vent. 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. Empty the gas tank, properly dispose of the old fuel and try a fresh batch of gasoline.

What causes a lawnmower engine to surge up and down?

Airflow Issues 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 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.

Why does my mower rev up and down?

The lawnmower may rev up and down if the spark plug is damaged or having an unbalanced adjustment. You want to make sure the cables connected to the spark plug don’t become loose and move unsteadily in a particular direction. Apart from that, check inside the spark plug if there are any corrosion build-up issues.

Why is my lawn mower engine hunting?

If your lawnmower experiences surges and hunting sounds when it uses a mower, you may have an air issue. blocked air, especially sporadically, is hard to expel. Slowing the engine down may result from this condition. Engine power may become higher upon moving or clearing the blockage.

Can a clogged air filter cause surging?

Air Supply A clogged or obstructed air filter can cause surging at idle, and foreign objects can enter the filter housing at any time. Any debris in the filter or housing might restrict air flow to the engine enough to affect idle speeds.