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How to Store Your Mower for Winter

Easy winter lawn mower maintenance

Storing your outdoor power equipment correctly is extremely critical for anything with an engine. If avoided, you risk serious mechanical and or performance issues when it's time to use the machine next spring. To help ensure your mower starts and performs its best, we compiled a list of must-do winter storage procedures.

Before starting these procedures on your own, refresh your knowledge on important safety practices and procedural instructions in the operator's manual for your unit.

1.    Stabilize lawn mower fuel

‚ÄčIf anything tops the list in terms of storage importance, it's stabilizing your fuel. At Gravely, the most common maintenance issues we learn about are those related to deteriorated fuel that clogs the fuel system.

Gasoline breaks down in as little as two weeks, let alone the two or three months during seasonal storage. When fuel deteriorates, it turns to a gel-like substance, clogs your fuel system and prevents your engine from starting or running. Not only does this cost downtime, it leads to unserved clients and repair bills. 

Adding a quality fuel stabilizer to your gasoline prevents fuel from deteriorating and helps you avoid problematic issues.

How to stabilize gasoline:
a.  If your mower has fresh fuel (gasoline purchased less than two weeks ago), estimate how much fuel is in the tank. You will need to know that quantity to correctly calculate the amount of fuel stabilizer needed.
b.  Add fuel stabilizer to the fuel tank (or tanks) according to the instructions on the fuel stabilizer packet or bottle.
c.  Start the engine and operate the mower for about ten minutes to incorporate the stabilizer throughout the fuel system.
d.  If the mower has a carbureted engine, keep the engine running, close the fuel valve and allow the engine to stop on its own. If it's an EFI engine, simply switch the key to the off position and remove it.
e.  After the engine stops, turn the key to the off position and remove the key.
You can purchase fuel stabilizer online or visit your nearest Gravely dealer.

How ethanol fuels can cause fuel-related issues
Ethanol is a solvent and can dissolve varnish buildup in older engines, and when that varnish breaks loose, those deposits can travel through the fuel system and clog it. 

How to avoid ethanol related issues
Fuel blends with an ethanol content of 10% or less are technically acceptable in small engines, including those that power Gravely lawn mowers. If you use ethanol-blended fuels in your equipment, add a fuel stabilizer plus ethanol treatment to your fuel.

If you've never done this before, it's simple, but remember, it’s critical to follow the instructions exactly as they're outlined above for effective results.

Can fuel stabilizer be added to old gas?
Fuel cannot be rejuvenated. If the fuel in your mower tank was pumped fresh more than two weeks ago, either drain and dispose of it responsibly, or use it now. After the fuel is expelled from the tank, add fresh fuel to the tank or tanks and stabilize according to the instructions below to help flush old fuel residue out of the fuel system.

Remember, in carbureted engines, fuel needs to fit through the tiny hole in the carburetor jet, and it only takes the smallest bit of bad fuel to clog it – which is why it’s SO important to prep your mower for winter.

2.    Change lawn mower oil

After a full season of use, your engine needs an oil change and a new oil filter.

Oil changes are easy to perform and they don’t take much time. The engine is your power plant and it needs to be protected so it can continue to perform well and reliably. Though performing an oil change isn't absolutely necessary before storing outdoor power equipment, it’s good to do it now when it’s top-of-mind, and it removes something you would otherwise need to do at the beginning of the next mowing season.

How to change lawn mower oil:
A brief outline for engine oil changes are listed below. For the full oil change details, reference the instructions in the engine manual for your unit.

a.  Remove the drain plug and allow oil to drain into a container. Use a funnel if necessary.
b.  Once drained, reinstall the drain plug and tighten to the specification in the manual.
c.  Remove the oil filter, allow the oil to drain from the filter and into a container and dispose the filter.
d.  Dip the tip of your finger in the used oil and apply a thin layer of oil around the rubber gasket of the new oil filter.
e.  Install the new oil filter and tighten according to the specifications in the manual.
f.   Remove the cover from the engine fill port and add the correct volume and type of engine oil listed in the manual.
g.  Reinstall the fill port cover.
h.  With the parking brake on, start the mower and visually inspect the engine to ensure oil isn't leaking. Stop the engine when you confirm oil isn't leaking from the drain plug or around the filter.

3.    When to change a lawn mower air filter

Lawn mower air filters should be checked before storage and replaced, if necessary. Like oil changes, it’s not necessary to complete before storage, but as long as it’s top-of-mind right now, you might as well do it.

Why you should change a lawn mower air filter
a.    Air filters protect engines. Clogged air filters don’t.
Dust, dirt and other debris sucked in through an engine’s air intake can damage the engine, which is why each engine has an air filter. As the engine ‘inhales,’ the filter catches debris and prevents it from entering the engine and harming its delicate components.

Even the smallest airborne particles can damage an engine. And while the engine air filter does its job catching these particles, it collects so much debris over time that it becomes full and less effective.

b.    Clogged air filters reduce power and efficiency and increases fuel consumption.
A dirty air filter's restricted airflow makes an engine work harder (using more gasoline) and reduces its efficiency. That’s why it’s important to check the filter regularly and replace it when needed.

4.    Change lawn mower hydro oil

Like engine oil, transmission fluid needs to be changed annually or at the intervals listed in your manual.

Combustion doesn’t occur inside a transaxle, however the friction of the mechanics inside the unit create heat and degrade the oil. Commercial lawn mowers that are operating as much as 12 hours per day must have their transaxle oil changed multiple times throughout the mowing season – or however often as outlined in your unit's operator's manual – which is usually after the first 75 hours of operation and every 400 hours thereafter.

Now that you're at the end of your season, chances are it’s time to change it. And if you have some downtime, let’s do it now so you don’t have to at the start of the season.

The instructions below are just an outline, so refer to the operator’s manual for complete details.

How to change lawn mower hydro oil:
a.  Operate the unit for a few minutes to warm the fluid.
b.  Stop the unit and wait for hot parts to cool.
c.  Remove the transaxle filter guards, if equipped.
d.  Remove oil filters, drain filters and dispose.
e.  Remove the fill plugs from transaxles.
f.   Wipe the filter mounting surfaces clean.
g.  Lubricate rubber gasket on new oil filters with hydraulic oil.
h.  Install filters onto transaxles and torque to specification.
i.   Reinstall filter guards with original hardware and torque to specification.
j.    Add the correct type of hydraulic oil to the transaxles until oil appears at the bottom of the oil fill openings.
k.   Reinstall oil fill plugs and torque to specification.
l.    Add hydraulic oil to the expansion tanks until fluid level meets the cold fill line.
m.  Purge the hydraulic system according to instructions in manual.

5.    Connect battery charger

Seasonal battery storage is important; connect a battery trickle charger or battery tender to your lawn mower battery to keep it healthy.

If you own a motorcycle or other seasonal recreational equipment, you might be familiar with this procedure. When not used for extended periods, batteries in cars, recreational and outdoor power equipment can discharge and lose their charge capacity. To keep your battery in good health for next season, connect a battery tender or trickle charger to the battery.

Battery tenders are different from trickle chargers. A trickle charger applies a constant, weak charge to the battery and keeps it fully charged through the offseason. Battery tenders charge a battery, stop charging once the battery reaches a full charge, and then start charging again when the battery drops below a certain voltage.

Both options are good solutions for maintaining a mower's battery health, but some resources suggest a battery tender is the better option because the constant charge from a trickle charger can damage the battery.

6.    Clean the lawn mower deck

Grass, dirt and debris buildup under the deck and around the spindles can rust and corrode critical mower deck components, affect the mower's performance, cut quality, and your reputation as a landscape professional.

How to clean the mower deck:
Remove the blades according to the instructions in your operator’s manual before cleaning the deck.

If you don’t have a lift or a system where you can safely access the underside of the deck, you can remove the deck from the chassis very easily. Deck removal instructions are listed in the operator’s manual for your unit, but a general outline is available below:

a.    Remove the PTO belt from around the clutch.
b.    Disconnect the deck lift linkages.
c.    Disconnect the deck mounting arms.
d.    Remove the deck from under the unit.
e.    Carefully remove the blades.
f.    Clean the debris from under the deck with low-pressure water. Using high-pressure water can damage certain components.

How to remove rust from a lawn mower:
If you see rust forming on bare metal areas under your deck, remove it with an abrasive tool like sandpaper, clean the area and cover it with touch-up paint.

Learn how to remove a Gravely mower deck.

Check mower belts and blades
It’s not critical for storage maintenance, but if the deck is removed, it's an opportunity to check blade condition and to sharpen according to the instructions in your operator's manual.

If blades are damaged or worn too much, replace them. Also, check your belts for signs of wear and replace if necessary.

Replacement Gravely commercial lawn mower parts
Our objective to providing a comprehensive checklist for seasonal maintenance is to help keep your Gravely mower running as good as the first time you used it. Keep your gravely performing at its best with:

•    Fuel care / stabilization
•    Regular engine oil and oil filter changes
•    Regular transaxle oil and oil filter changes
•    Regular air filter changes
•    Regular cleaning
•    Regular blade sharpening
•    Regular lubrication around the caster wheels

To find genuine OEM Gravely parts and accessories, visit your local Gravely dealer.