Your question: What causes a small engine to hunt and surge?

A dirty or gummed up carburetor causes an engine to surge. If you feel comfortable working on carburetors, unbolt the bowl and clean it thoroughly. Check whether the float moves up and down without sticking, and clean the tiny ports on the bowl hold-down bolt.

What causes my lawn mower engine to 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 would cause a small gas engine to hunt and 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 surging in a small engine?

The fuel tank cap has a small hole, which allows air to flow into the tank and create back-pressure to help deliver fuel to the carburetor. Dust or dirt can plug up this hole. As a result, the carburetor won’t get enough fuel, leading to surging. Surging can also occur due to water contaminating your fuel.

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Why is my small engine surging?

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.

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.

What causes RPM to fluctuate while idling?

Why does my engine’s RPM seem to fluctuate (runs rough)?



Many engine performance problems can be linked to maintenance issues such as stale fuel, dirty air filter, fouled spark plug, and deteriorated oil. … Engine hunting and surging at idle is usually caused by a fuel delivery, air leak, or governor system problem.

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 does it mean when an engine is hunting?

Engine hunting is nothing but variation in the engine rpm continuously(fluctuating).the engine rpm may be varied continuously due to abnormal condition of centrifugal governor inside the fuel injection pump or fast idle control device.the amount of fuel injection in idling condition per cycle would be fixed, itshould …

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How do I fix my Kohler engine surging?

You may have already done these but may be worth mentioning; Make sure the gas tank cap vent is working ( take the cap off and see if the surging stops). Check the air filter. Check/replace the fuel filter. Drain old gas, make sure there isn’t any water that may be present in the tank left behind.

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