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Lawn Mower Won't Start After Winter, Here's What Could Be The Reason..

Written by William
Last Updated on January 24, 2023

Why Is My Lawnmower Not Starting After Winter?

There's nothing worse than putting your lawnmower away after cutting season, only to remerge it from your shed after a couple of months and find it won't start.

Lucky for you, this is a common problem, and lawnmowers do tend to have issues starting after winter and can be solved by troubleshooting a couple of different parts on your mowers machines such as the spark plug, blades and gas. Failing this, it would be advised to call the manufacturer.

We have put together a large list of reasons as to why your lawn mower might not be starting after winter and how to fix them so as you can get to the root of the problem and revive your mower for a new cutting season!

So without further ado, let's get started.

Common Reasons Why Your Lawnmower Isn't Working After Winter

From old fuel to white smoke and faulty spark plugs, there is a range of reasons as to why your lawnmower might be giving you problems after being stored away during the winter season.

We have listed some of the most common reasons below to help you identify the issue with your mower and fix it.

Faulty Spark Plug

One of the most common reasons as to why your lawnmower isn't starting may be due to the spark plug. If your spark plug has been left unused for a long period then you might come back to a couple of issues.

To check if your spark plug is working you can remove the lead and unscrew the plug, then reattach the lead and place the tip of the spark plug against something that is metal.

Startup your recoil and watch for a spark to appear, if the spark is not lighting or your not sure then it might be worth replacing your spark plug to see if this fixes the issue.

Stale Fuel/Wrong Fuel

Over the winter months, your lawnmower should have been drained of fuel from the previous use, if not then you might have bad and old fuel causing problems within your lawnmower.

Try getting rid of any old fuel with an extractor if this is the case.

Also ensure your machine is filled with the right type of gas and is not mixed with oil, as well as ensuring the fuel tap on your model is switched on so as fuel can flow to the carburettor freely and start your machine.

Check Your Carburettor Has Fuel

As we mentioned above, if you have any issue relating to fuel reaching your Carburettor then you might have the reason as to why your mower is not starting.

Most mowers either have a bowl or red primer bulb on the side. To check if your mower has fuel with a red primer bulb simply unscrew the air filter on your machine and press the primer bulb to see if any fuel is being pumped into the engine.

For the bowl carburettor simply undo the drain plug at the bottom and see if fuel flows out, if you see fuel flow out of fuel being pumped to your carburettor then your mower has no issue with supplying fuel there.

Look for Blade Obstruction

Raise your mower on some cinder blocks or remove the spark plug and tip the mower so as the exhaust is facing down and the carburettor is up so as you can get a view of the blades underneath.

With time, obstructions such as grass and debris can get trapped in your mowers blades which may prevent them from turning and stop the engine of your machine starting if the blades are not getting any movement.

Check underneath for anything unusual like this and clean the under of your mower with a screwdriver or knife, if you clean with water take care to not get any electrics wet.

Check The Lawn Mower Choke

Ensure the choke of your mower is set to start so as it can choke the air in the valve of your mower and help it start.

To check if a manual choke is working you can remove the air filter of your mower and look through to the carb, then operate the throttle and watch to see if the valve is closed.

If your valve is not closing you may have to loosen the cable below the carb and reposition it, this can often be caused if something has nested around there while your mower was stored in the winter.

The Battery Is Worn Out

With time, if you are using a battery lawnmower, these batteries can become worn out and flat from not be charged after the winter months. Try a new battery in your mower to see if this the issue.

Other Reasons As To Why Your Lawnmower Isn't Starting

If you have tried all of the above and your mower still will not start after winter then you might have some other less common issues occurring with your mower.

Some problems such as your lawnmower starting then dying after a couple of minutes, or running too hot may be among the problems happening.

We have put together a few more troubleshooting ideas below to help you out.

There Is a Split Primer Bulb

If you have stored your mower outside during the winter where it is cold then you could easily have a split primer bulb. This could be a reason as to why your mower isn't starting so you should get replaced immediately.

It's The Kill Switch/Micro Switch

Depending on the type of mower you have your model will have a kill switch or microswitch.

The kill switch on a mower has to disengage for your mower to get a spark and start running, however, if anything has obstructed the kill switch or there is a disconnection then you might have an issue.

To get a closer look at the kill switch you can remove the cover of the cable that runs from the safety lever to the kill switch and operate the lever to see if the switch disengages, if it does not then you know there's a problem.

For a microswitch, this switch has to be activated for it to work from the safety lever, follow the same steps above to check and listen out for a click to see if this type of switch is working.

Your Mower Is Hydrolocked

If your lawnmower was tipped in an upright position when stored then it could potentially be hydro locked.

When hydro locked, a mower will feel difficult to pull over, to fix this try removing the spark plug and pulling the lawnmower to start it a couple of times, then reattach the spark plug and see if your mower is working.

Check The Cooling Fins

Nests can appear over the winter months and be a reason for your lawnmower starting then cutting out.

Remove the starter recoil of your mower and blow to clean any cooling fins on your mower, you should also change the spark plug if this was your issue.

There Is White Smoke

Tipping your lawnmower the wrong way during storage in winter can be a common culprit of white smoke.

White smoke is most of the time not an issue and is just the result of the oil in the mower reaching the wrong places and causing the smoke, you can fix this by running your mower till all the smoke has disappeared.

How To Winterize Your Lawnmower

Now you have looked at all the troubleshooting problems above and hopefully determined what the issue is with your mower, we have put together some tips on how to prepare your mower for winter storage in the future and avoid any preventable issues from when you take it out for the new season.

  • Put stabilised fuel - Fuel stabiliser can allow you to keep your lawnmowers tank full of fuel during winter without any issues such as stale fuel clogging your engine. Having a full tank can also stop rust from forming and clogging your mowers carb.
  • Clean the mower - Completely clean your mower before storing and remove any debris or grass that is trapped beneath. Always remove the spark plug before hosing your mower down.
  • Take out the battery - If your mower uses a battery then you should detach it from your model and take it off for storage separately.

Frequently Asked Questions About Lawnmowers Start-Up Problems After Winter

Why is it an issue to leave gas in your mower over winter?

Leaving fuel in your mower over winter can clog up your carb and cause rust in your mower, both problems can cause startup issues with your mower.

How do I clean my mower?

You can clean your mower by using a screwdriver to remove any stuck debris and hosing it down afterwards, always disconnect the spark plug before doing this to prevent accidental start-up and remove any electricals.

Should I change the air filter on my lawnmower?

Yes, a bad air filter can stop the fuel in your mower from burning properly by stopping the airflow.

To fix this you can replace the paper filter or clean the oil-soaked one depending on your model.

Final Words

Overall, most problems related to your mower not starting after winter are easily fixed with the troubleshooting list above and your model's manual.

To prevent issues from happening when you get your mower out next spring, you should always make sure you are winterizing your lawn mower before storing it away for long periods in the future.

About the author
Written by William
I have always had a passion for gardening and that with a background in selling lawn mowers for the past 10 years, I have become very knowledgeable in all types of gardening tools. The site TheBestMowers.co.uk was created as a hub where I can review and write about all of the tips around gardening.
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