How Do You Start a Lawn Mower After Winter [or After It’s Been Sitting for Years!]

Winter is over and if you’re like me, you’re looking forward to starting your lawn mower up again!

There are a few things we should do before we start our mower after it’s been sitting idle for a while, which is what I’ll go through in this article. 

Before you start reading about getting your lawn mower started after winter – put your battery on charge. It’s bound to be flat after sitting for a few months (or years!) so that’ll give you a head start on the first step.

I’ll also give you some good tips on making the whole process a bit easier – keep reading!

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Step 1. Put Your Battery on Charge

The very first to do is put your battery on charge. A battery charger is the easiest way, but if you don’t have one, you can jump-start it later on.

By the way, if your battery looks like this:

battery-corrosion

Stop…

It’ll need cleaning first – boiling water is one of the easiest (and cheapest) ways to get rid of the corrosion. Make sure your terminals are nice and clean. 

Another tip when you park your lawn mower up for a while is to disconnect the battery.

I have an isolator switch on my battery because it was going flat all the time due to an electrical draw somewhere. Draws are notoriously hard to find so an isolator switch is an awesome solution – or pull one of the leads off. 

Step 2. Fresh Gas

how-to-start-a-lawn-mower-after-winter

The second thing to do is make sure your lawn mower has fresh gas.

The easiest way to tell if the gas is good is to smell it. Not too much, mind you – it’ll go to your head.

Just have a sniff. If the gas smells bad, yuck, or weird – it has to go.

If the gas smells fine, get some new fuel and fill it up.

Step 3. Drain the Carburettor

This step is highly advised, but optional.

The drain screw can be pretty hard to get to on some mowers, for example, so it might not be practical for you to do this step.

If you can drain the carburetor – awesome!

Time to take your lawn mower outside. This is a messy business so you really want to make sure you take your mower somewhere where a bit of gas on the ground can be cleaned or doesn’t cause issues.

There’s a drain screw on the bottom of the bowl that allows you to drain the old gas out. Take it out and drain it until you smell nice, fresh gas coming through.

Most mowers have gravity-fed gas, so the gas will run through by itself. It can also drain your whole gas tank so make sure you put that screw back in when the fresh gas comes through!

Some mowers, like mine, have a fuel pump. You can still drain the carburetor on a lawn mower with a fuel pump, but if you want to pump more gas through to flush it, you’ll have to wind the mower over.

Be careful, though…

Although it’s good to flush the gas through, you don’t want to burn out your starter motor winding it over 1,000 times!!!

Does Your Gas Look Murky?

Yes? That sucks!

You might be in a bit of trouble if the gas that drains out is murky. Most likely, your carburetor is blocked and you’ll need to clean it before your lawn mower runs properly (or at all).

I mean, yeah, you might get lucky.

Sometimes, even if it is murky, you might still the mower going, especially if you use it regularly. If the gas is murky and you only use it once or twice then park it up again for ages, your carburetor will be blocked with gunk.

If you use the mower a lot, there’s a small chance it’ll come good with some fresh gas.

Most likely though, if the gas is murky, it’ll get worse and you’ll have to clean the carburetor.

I have some good tips on how to easily clean carburetors below – they might save you a lot of time and money!

So, you’ve drained the carburetor until nice, clean fuel is coming out. I hope you’ve put the screw back on the drain, too.

Now it’s time to wash it or wait a while.

Step 4. Wait or Wash

Don’t try and start your lawn mower straight away. I mean, it’s covered in the gas you just drained out.

If you really have to use your mower right now, at least give it a gently hose-off and move the mower away from the spot where you drained the gas, so you’re not sitting in a puddle of gas.

Be very gentle with the hose, you don’t want to wet all your electrics. If you get those wet, your mower won’t start. Just give it a gentle wash-off.

Step 5. Check the Oil

The last thing to check before you start your lawn mower after winter is the oil.

Check that it looks good, and it’s filled up to the right level.

Awesome!

We have good fuel, good oil – we are ready to do some mowing!

How to Start Your Mower After It’s Been Sitting for Years

If it’s been more than just a winter – the steps to start your lawn mower are very similar to the steps above, except that your carburetor is most likely blocked.

Ugh.

There’s a very high chance you’ll have to clean the carburetor before anything else, but that’s usually the worst of it. 

I used to get heaps of small engines from the dump to fix them up. Most of the time, all that was wrong with them was a blocked carburetor.

In the end, I got so sick of cleaning carburetors, I stopped getting them!

Tips for Cleaning Carburettors

mercury-quicksilver-evinrude-engine-tuner-power-clean

If you’re on a farm or homestead and you have some gear that sits around for part of the year – like generators and lawn mowers – get yourself a can or two of spray tune.

I have the Johnson Evinrude OMC Engine Tuner and the Quicksilver Power Tune (Mercury) – it’s the same stuff and they both work really, really well.

This stuff’s a real lifesaver when you need it!

We had a big storm that knocked the power out the other day. My daughter and I went out to get the generator started and, of course, it wouldn’t go because it had been sitting for months.

I pulled the bowl off the carburetor and sprayed it full of spray tune. Then I sprayed it up into the carburetor and tried to get a bit of it to go up into the jets.

I left it to soak for as long as my daughter had patience for. She’s 8, so it wasn’t long.

It worked!

We started it up and she fired right up and kept running all night.

Get yourself some – it might save your bacon one night when you really want your generator going, or that day when you really need your snow blower and you can’t go to the shop because your driveway is blocked by an 8ft mountain of snow!

I’ve actually had this other idea….

It’s not tested fully yet, but I reckon there’s a good chance it’ll work.

  1. Start by draining the carburetor.
  2. Get a long hose with a small funnel on top.
  3. Fill the carburetor up with spray tune until it comes out of the drain screw.
  4. When you see the spray tune coming out, put the screw back in (don’t waste it, it’s not cheap!)
  5. Fill the carburetor up with this stuff until it comes out the top.

Now have a beer and wait. And wait. It’ll take ages and it’ll take patience. Like, 24 hours. 

The spray tune comes out as foam, so you’ll have to wait for it to settle into liquid so it can get inside the carburetor.

It takes a lot of patience to fill a hose, I can tell you that.

If this doesn’t work and it still runs crappy – you’ll have to pull the carburetor off, pull it apart,  and soak all the individual pieces in the spray tune for 24 hours. 

What I normally do is get all the jets and the small parts and sit them in the bowl. Then I fill up the bowl with the spray tune and let them soak in it. You can also use a different bowl, of course. 

Once it’s worked, all the jets and brass parts will be a shiny, golden buttery color.  After they’ve been soaked, I like to clean the parts off with electrical contact cleaner, carburetor cleaner, or brake cleaner. If you don’t have that, you can use petrol to rinse them.

And also, it’s best to blow through all the holes in the carburetor with compressed air. Make sure everything is out first, so you don’t blow little parts all around the place. 

It really sucks when that happens!

Try and do this on a clean bench so that when things roll away, they don’t get mixed up with other things. Maybe even a clean floor in case you drop stuff…

But, if you’ve got the time to just leave it – this would make a super easy way to clean your carburettor, and anyone can do it!

Last update on 2021-10-24 / Affiliate links / Images from Amazon Product Advertising API

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