Briggs and Stratton Lawn Mower Won’t Start After Sitting?

Lawn mowers are commonly deployed when grass is actively growing. During winter and severe drought, these machines are usually idle in a garage or shed. There is a protocol for storing a lawn mower. Let look at why your lawn mower is turning but not starting.

If your lawn mower won’t start after sitting, check if it is out of fuel, carburetor and air filters are clogged or spark plugs are improperly fitted. Trying to fix these problems can bring your mower’s engine back to life. It nothing happens, let a professional diagnose and fix your lawn mower’s problem.

Exercise safety when fixing your lawn mower. Overstayed fuel can spew toxic fumes, the need to work in an open space or well-ventilated area. There is also danger of fire as gas or petrol are highly flammable. Always disconnect spark plugs when working to stop the engine from accidentally starting.

Why Briggs and Stratton Lawn Mower Won’t Start after Sitting

There many reasons why your Briggs and Stratton lawn mower won’t start after sitting. They are not solely applicable to this model but also to similar models from other different manufacturers.

1. Fuel problem

Fuel is needed to power a gas lawn mower engine. The engine will not start when out of gas, the fuel has gone bad or there is a clog in the fuel line. Unused gas left in a lawn mower over the winter can get stale, gum up parts and invite rust. This is the reason why fuel should be stabilized when winterizing a lawn mower.

To be sure if fuel is the problem, see if there is any fuel in the tank. Next, if you did not stabilize the remained fuel before storage, then you have to drain it and add a new one. Then try to start the engine. If nothing happens, try the next hack.

2. Bad engine oil

Engine oil is helpful in lubricating moving parts in the engine. Overtime, engine oil can get dirty and you’ll need to change it before it wreak havoc. How often to change your lawn mowers engine oil may depend on the manufacturer’s recommended hours of runtime or the lawn conditions.

After a long storage, engine oil may go bad or gum up. This will definitely lead to problem starting your engine. To inspect this, use the provided dip stick to check if the available engine oil in the crankcase is enough and it’s in good state. If the oil is too dirty then you’ll need to change it.

Oil change for a lawn mower should be done after the first 5 hours of operation for a brand new lawn mower. For your existing push lawn mower, do it after every 40 to 50 hours of run time. Tractors and riding lawn mower engine oil need to be changed at the start of every season.

3. Clogged carburetor

A carburetor helps in mixing air and fuel before being channeled into the ignition chamber of the engine. Sometimes dirty and debris can end up in the carburetor especially when the air filters are clogged or damaged. Lawn mower not starting is one of the signs of a troubled carburetor.

To solve this problem, remove the lawn mower casing and remove the air filter. You will them be able to access the carburetor, Clean your lawn mowers carburetor air and fuel lines. Replace rusty bowl and its nut, pin and the float gasket.

4. Corroded or disconnected spark plugs

Spark plugs ignites the air/fuel mixture to create explosion that makes an engine to produce power. During a long storage of your mower, spark plugs can get corroded or disconnected from their socket. It is obvious that your engine will not start without proper functioning of spark plugs.

To fix this problem, simply purchase a new spark plug for your lawn mower type and install it. Once you locate the plugs, simply use spark plug socket wrench to remove the old plug and install the new one. Tighten the plug but don’t overdo it to a point of causing damages.

5. Damaged or clogged air filter

Air filters clean the air to remove debris before it’s allowed to mix with fuel in the carb. A damaged or clogged air filer can lead to number of problems in a lawn mower engine. First of all, your mowers carburetor will not receive sufficient air for mixing with the fuel which will give it trouble starting.

If this is the reason as to why your lawn mower is not starting, then you should replace or clean air filters as directed in the user manual. Briggs and Stratton lawn mower air filters are affordable and you can get them in a nearby hardware or order them online.

6. Battery problem

If your lawn mower rely on a battery power to ignite the engine, then there is a chance that your lawn mower battery is out of charge or the terminals are corroded. This usually happen when you forget to remove the battery before the long storage of your lawn mower.

To fix this problem, simply remove the lawn mower battery and clean its terminals using a wire brush. Check the level of water and top it up where necessary. Recharge the battery and connected it back then try again to start the engine.

How to Prepare your Lawn Mower for Storage

Several off-season tune ups can help your Briggs and Stratton lawn mower to remain in good condition during a long storage.

Use fuel stabilizer

Some resources will tell you to drain any remaining fuel before storing your lawn mower for winter. We found this to be inappropriate as this is a waste of money. Additionally, an empty fuel tank is open to condensation which will invite corrosion or rusting.

What you need is to fill the fuel tank to about 95% with a mixture of fuel and stabilizer. Then run the engine for about 5 to 10 minutes so that the stabilized fuel can also work in the fuel line. This additive will stop any chemical reaction or breakdown from happening thus preserving the engine.

Change engine oil

Your lawn mower has been working during the entire mowing season. By now the engine oil is now dirty and worn out. This old oil can gum up or go bad if stored with your lawn mower for longer. For everything to start off well the next season, change your lawn mower oil as directed in the user manual.

Remove the battery

Remove a battery from your lawn mower before storing. Clean it as you brush the terminals with a wire brush to remove any corrosion. Use a cloth on the casing with soapy water and dry it with another piece of cloth. Store the battery indoors away from heat, gas cylinders or water.

Change air filters

Before storing your lawn mower for winter, replace the old air filters. By now, the current air filters are clogged or worn out. New or clean air filters will ensure that your engine is starting well when you start your lawn mower the coming season.

Replace spark plugs

This will be the ideal time to replace your mower’s spark plugs with new ones. Storing it with the current worn out plugs may make it difficult to start your lawn mower after sitting for long. Cleaning the oxidation layer may be an option if you recently replaced them. Otherwise get brand new plugs for your mowing machine.

Clean the mower

Disconnect spark plugs and hose your lawn mower to remove grass, leaves and mud. Let it dry completely before storing in a clean dry place. Your garage, warehouse or a shed are ideal place to store your lawn mower.

Final Thought

Briggs and Stratton are leader in production of small engines and lawn mowers. Their products are incredibly durable and reliable. A Briggs and Stratton lawn mower can serve for many years if you follow the right maintenance and storage protocols provided in the user manual by the company.

We have seen what can make your lawn mower not to start after sitting for long and how to fix it. You can avoid the problem by adequately preparing your lawn mower for storage as directed in this guide or by the mower manufactures. This will give you a head start in enjoying well-manicured lawns.

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