How To Start Lawn Mower Briggs And Stratton

If you’re wondering how to start lawn mower Briggs and Stratton, you’re in the right place. For a Briggs & Stratton engine, ensure the fuel valve is on and the choke is set correctly. This simple check solves many common starting problems before you even pull the cord. This guide provides clear, step-by-step instructions for starting both older and newer models, including those with key electric start systems.

Starting a Briggs & Stratton lawn mower is a straightforward process when you follow the right steps. The exact method can vary slightly depending on whether your engine is cold or warm, and if it has a primer bulb or a choke. This section covers the universal pre-start checklist and the two main starting procedures.

Essential Pre-Start Safety And Checks

Before you attempt to start the engine, a few critical checks are necessary for safety and to ensure a smooth start. Never skip these steps.

Clear the Mowing Area: Remove any sticks, toys, stones, or debris from the lawn. This protects you and your mower from flying objects.
Check the Oil Level: Use the dipstick to ensure the oil level is between the “Full” and “Add” marks. Low oil can cause severe engine damage, and many Briggs & Stratton engines have a low-oil shutdown sensor that will prevent starting.
Inspect the Air Filter: A clean air filter is crucial. A dirty filter can restrict air flow and make the engine hard to start. Give it a tap to dislodge debris or replace it if it’s very dirty.
Verify Fuel Level and Quality: Use fresh, clean gasoline that is less than 30 days old. Old fuel is the number one cause of starting issues. If the fuel is stale, drain the tank and carburetor and refill with new gas.
Engage the Parking Brake: On self-propelled models, set the brake.

Starting A Cold Engine (With Choke Or Primer)

A cold engine needs a richer fuel mixture to start. Your mower will use either a choke lever or a primer bulb to achieve this. Here’s how to start lawn mower Briggs and Stratton engines from cold.

Locate the Fuel Valve: If your model has a fuel shut-off valve on the fuel line or tank, turn it to the “On” position.
Set the Throttle: Move the throttle or speed control lever to the “Fast” or “Start” position, often indicated by a rabbit symbol.
Engage the Choke or Prime: For a choke, move the lever to the “Full Choke” position. For a primer bulb, press it slowly 3 times. You should see fuel moving in the primer lines.
Pull the Starter Cord: Stand firmly with one foot slightly behind the other. Grasp the handle and pull the cord smoothly and briskly. Do not yank it or pull it all the way out. It may take 2-3 pulls.
Adjust the Choke: Once the engine sputters or starts, quickly move the choke lever to the “Half” or “Partial” position. Let the engine run for 10-15 seconds, then move the choke to “Off” for normal operation.

Starting A Warm Engine

If the engine has been run recently and is still warm, the process is simpler. You typically will not need the choke or primer.

Set the throttle to “Fast.”
If your model has a choke, set it to the “Off” or “Run” position. Do not press the primer bulb.
Pull the starter cord. A warm engine should start within 1-2 pulls.

Using The Electric Start System (If Equipped)

Many newer Briggs & Stratton mowers feature a convenient push-button electric start. Here is the procedure.

Insert and turn the key to the “On” position (if equipped).
Ensure the battery is charged. Listen for a click when you turn the key; a weak battery may not turn the engine over.
Set the throttle to “Fast” and the choke to “Full” if the engine is cold.
Press and hold the electric start button, usually marked with a lightning bolt. The engine should crank and start. Release the button immediately.
If the engine doesn’t start after 5 seconds of cranking, stop. Wait 60 seconds to prevent overheating the starter, then try again.

Troubleshooting Common Starting Problems

Even with proper steps, your Briggs & Stratton mower might not start. This section helps you diagnose and fix the most frequent issues.

Engine Won’t Turn Over Or Pull Is Very Hard

If the starter cord won’t pull or is extremely stiff, do not force it.

Check the Blade Control Lever: Ensure you are fully depressing the lever that engages the blade. This safety interlock must be held down to release the engine flywheel brake.
Disengage the Blade: Make sure the blade engagement lever is in the “Off” position. Trying to start with the blade engaged can sometimes cause binding.
Inspect for a Seized Engine: If the lever is correctly held and the cord still won’t budge, the engine may be hydro-locked (with fluid in the cylinder) or seized. This requires professional repair.

Engine Cranks But Won’t Start

This is often a fuel, spark, or air issue. Follow this checklist.

Fuel System Checks

Old Fuel: Drain and replace with fresh gasoline.
Clogged Fuel Line: Check for kinks or blockages in the line from the tank to the carburetor.
Dirty Carburetor: Old fuel leaves varnish that clogs the tiny jets in the carburetor. Cleaning or rebuilding the carburetor is often necessary.
Faulty Fuel Cap: The fuel cap has a small vent. If it’s clogged, a vacuum can form in the tank, preventing fuel flow. Try starting with the cap slightly loosened.

Ignition System Checks

Spark Plug: Remove the spark plug. If it’s fouled with carbon, clean it with a wire brush. Check the electrode gap with a feeler gauge and adjust it to the spec in your manual (typically .030 inches). If the porcelain is cracked, replace the plug.
Spark Plug Wire: Ensure the wire is firmly attached to the plug.
Safety Interlock System: A faulty safety switch (under the seat, on the blade lever, etc.) can prevent spark. Diagnosing these may require a multimeter.

Engine Starts Then Immediately Dies

If the mower starts but stops running after a few seconds, the likely culprit is fuel delivery.

Clogged Carburetor: The main jet may be partially clogged, allowing just enough fuel to start but not to run. Cleaning the carburetor is the fix.
Blocked Fuel Filter: If your mower has an in-line fuel filter, replace it.
Faulty Choke Linkage: If the choke does not open after starting, the engine floods and stalls. Check that the choke lever moves freely.

Seasonal Starting Guide And Maintenance

Proper storage is key to easy starting next season. Neglect here is why many struggle with the first start of the year.

Preparing For End-Of-Season Storage

This is the most important maintenance you can do.

Add Fuel Stabilizer: Run the engine for 5 minutes to circulate treated fuel through the carburetor. This prevents varnish buildup.
Change the Oil: Old oil contains contaminants. Change it while the engine is warm so debris drains completely.
Remove the Battery: For electric start models, disconnect and remove the battery. Store it in a cool, dry place and charge it periodically over winter.

First Start Of The Mowing Season

After long-term storage, a few extra steps will ensure success.

Install a Fresh Spark Plug: This is a cheap and effective way to improve starting reliability.
Check and Change the Oil: Verify the oil level and condition. If you didn’t change it before storage, change it now.
Use New Fuel: Completely drain any old, stabilized fuel from the tank and replace it with fresh gasoline.
Prime Carefully: You may need to press the primer bulb a few extra times to refill the carburetor float bowl with fuel.

Frequently Asked Questions

Why Does My Briggs And Stratton Lawn Mower Have No Spark?

The most common reasons for no spark are a fouled or damaged spark plug, a loose spark plug wire, or a triggered safety interlock switch. Check and replace the spark plug first. If that doesn’t work, the ignition coil or a safety switch may be faulty.

What Is The Correct Way To Prime A Briggs And Stratton Mower?

Press the primer bulb slowly and firmly 3 times for a cold start. You should see fuel moving through the clear primer lines. Do not over-prime, as this can flood the engine. For a warm start, do not use the primer.

Should The Choke Be Open Or Closed When Starting?

The choke should be CLOSED (or “On”) for a cold start to restrict air and enrich the fuel mixture. Once the engine starts, open the choke (move it to “Half” then “Off”) within 30 seconds to prevent flooding. It should always be OPEN (“Off”) for a warm start.

How Do You Start A Briggs And Stratton Lawn Mower After Winter?

Begin by ensuring you have fresh fuel and a new spark plug. Check the oil level. Set the choke, press the primer bulb 3-5 times to refill the carburetor, and then pull the starter cord. It may take a few extra pulls to get fuel fully through the system after long storage.

Where Is The Fuel Shut Off Valve On A Briggs And Stratton Mower?

Not all models have one. If yours does, it is typically a small lever or knob located on the fuel line between the gas tank and the carburetor, or directly on the bottom of the fuel tank. Turn it so it is aligned with the fuel line to open it.