Since the hole is so small, it can plug up with dust or dirt during normal mowing operations. 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.
How do I fix my lawn mower surging?
Inspect the vent on your gas tank’s cap and clean it if it’s dirty. Drain the gas tank, clean the gas bowl, and add a fresh batch of fuel. Or you can inject fuel cleaner to clean the fuel line. After changing the fuel or injecting fuel cleaner run the lawn mower as usual.
Why does my lawn 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 causes lawn mower engine 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.
What does engine surging mean?
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. Misfiring happens when one of the cylinders of an engine’s combustion cycle fails.
What causes engine 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.
Can spark plugs cause surging?
Failing spark plugs can cause more than just surges or misfires. For instance, your car might sound rough when it’s idle.
Can bad gas cause surging?
A badly clogged fuel filter will reduce fuel pressure enough that the ECM must open the fuel injectors more to maintain the same amount of flow. … Fuel injectors contain very fine mesh filters, which can just as easily clog and cause the same sort of surging.
What causes a 2 cycle engine to surge?
The most common causes of a two-stroke engine surging include lack of airflow, contaminated fuel, faulty or old spark plugs, or a maladjusted carburetor. Fixing each of these issues involves removing parts of the engine, inspecting, and possibly replacing the equipment.
Why does my Kohler engine 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.
How do you adjust the idle on a lawn mower?
Start the mower and allow it to warm up under half-throttle for five minutes. Turn the idle mixture screw clockwise with the flat-head screwdriver until the engine begins to slow. Notice the position of the screw and turn the screw counterclockwise until the engine slows again.
How do you adjust the governor on a Briggs and Stratton engine?
First, loosen the arm until it is moving freely. Next, open the throttle to full capacity while making a note of which direction the arm moves in when the throttle moves through it. Once the throttle is fully opened, move the governor shaft in the same direction the governor arm traveled.
How do you adjust the idle speed on a Briggs and Stratton engine?
How to Adjust the Idle on a Briggs & Stratton Lawn Mower
- Loosen the set screw in the center of the air filter with a flathead screwdriver. …
- Tighten the idle adjustment screw, found on the side of the carburetor, by turning it clockwise just to the point where you feel it lightly touching the seat of the carburetor.
How do you know if your ignition coil is bad?
One of the symptoms of a bad lawn mower ignition coil appears when you are mowing the lawn and the mower gets hot and literally shuts off. The mower must cool down over a period of time and will start and run for awhile until it gets hot again, at which time it will shut off again.