The end of the season hits like a runaway Jet Ski. There’s packing to do, projects to finish, a cottage to button up, friends to see off, and motorized toys and power equipment to prep for storage. Often, this includes some combination of lawn mowers, garden tractors, generators, weed trimmers, chainsaws, pressure washers, log splitters, ATVs, UTVs, motor boats, trail bikes and personal watercraft. Something’s got to give, right? If you can, cut down on the friends. I’d suggest dropping one friend (couples count as one) per machine. If certain people in your household disagree strongly with your priorities (staying married is another end-of-the-season time killer) then it helps to know how to ensure your engines will fire up in the spring without burning yourself out in the fall.
The good news is, the basic process for winterizing anything with a gas engine boils down to just a handful of steps.
- Clean the machine thoroughly.
- Drain existing fuel. For 2-cycle engines, store dry of fuel. For 4-cycle engines, store filled with fresh fuel that has been treated with a fuel stabilizer.
- Squirt a little motor oil through the spark plug hole into each cylinder, and cycle the engine to make sure it is distributed. Or, spray fogging oil into the air intake with the engine running, then follow with a shot of fogging oil into each plug hole.
- Coat any metal prone to corrosion with a rust preventative, and lubricate any cables, chains, linkages and grease fittings.
Specific types of machinery will require a few extra steps. For example, you’ll want to treat the pump of a pressure washer to keep residual water from freezing or causing corrosion. More on that later. Inspect the machines while you work. With them clean, it’s the perfect time to perform repairs and regular maintenance. Anything you accomplish in the fall saves you time in the spring. At the very least, you can make a list of replacement parts to order during the off season.
Priority one: Purge old fuel.
If you take only one piece of advice from this article, let it be this: Do not store equipment with untreated fuel it. Gas begins to go bad in as little as a month. Damage caused by stale gas is the most common reason an engine, working well when put away, either won’t start in the spring or begins to run poorly. When fuel decomposes, it leaves behind acid and varnish deposits that can wreak havoc on engines, plugging tiny carburetor passages and causing flexible diaphragms and valves to stiffen and stick. Storage problems are compounded when the fuel is an ethanol blend. The alcohol in these fuels attracts water, which can prevent proper combustion, cause hard starts and promote corrosion. As a solvent, it eats away rubber and plastic parts, particularly in old equipment not made to withstand it, and dissolves gum and gunk in the tank, which are then carried throughout the engine.
Fuel stabilizers slow the deterioration of gas and help protect against gum deposits and corrosion. Add them only to fresh gas. They can’t turn bad gas good. Follow the label for the proper mix ratio. If using treated fuel for storage, fill the tank 90% to 95% full. Less fuel means more air in the tank, and therefore more water vapour and condensed moisture to contaminate the fuel. Filling the tank completely, on the other hand, leaves no room for the fuel to expand. Run the engine at idle for 10 minutes to ensure the treated fuel is spread throughout the system.
Some debate exists as to whether it’s better to run an engine dry or store it full of fresh, treated gas. No debate exists that either option is preferable to leaving stale gas in the fuel system.
Most manufacturers of 2-cycle equipment recommend that their products be run dry and stored empty. Two-cycle engines are the sort of simple small engines found in chainsaws and string trimmers. The majority require fuel and oil to be premixed. (Larger 2-stroke engines sometimes have separate oil tanks.) A typical procedure for winterizing a 2-cycle engine looks something like this:
- Drain fuel from the tank.
- Pull the starter handle or, if so equipped, press the primer bulb several times to remove remaining fuel from the carburetor.
- Run the engine at idle until it stops from lack of fuel.
- Remove the spark plug and pour a small amount of fresh 2-cycle oil into the cylinder.
- Pull the recoil starter handle a few times to distribute the oil.
- While watching the through the spark plug hole, gently pull the starter handle until the piston reaches the top of its travel. In this position, the piston is blocking ports that allow air into the cylinder.
- Replace the spark plug.
For both 2-cycle and 4-cycle engines, it’s a good idea to start using an ethanol-free, stabilized fuel well before you plan to pack up for the season. If things go sideways, and you can’t winterize everything, your engines will stand a fighting chance. Stabilized fuel drained from machines in preparation for storage can often be transferred to equipment still in use. Although ethanol blends are the norm today, many gas stations, especially those in boating and recreational areas, have one nozzle dedicated to ethanol-free, high-octane gasoline. It’s also worth noting that many premium 2-cycle oils contain stabilizers, and since they will be premixed with fuel, there’s no need to separately treat the gas. A good option, if you don’t mind paying a little more for convenience, is the canned premixed fuel available at most home centers and auto parts stores. It is ethanol-free, high octane and contains precisely the right proportions of both 2-cycle oil and stabilizer. Unopened, canned fuel will last for years.
For 4-cycle engines, manufacturers typically recommend storage with a nearly full tank of fresh stabilized fuel. In addition to reducing condensation in the tank, treated fuel may protect seals from drying out. It’s always wise to consult your operator’s manual for guidance on your specific machine. Many manufacturers also advise storing equipment with fresh oil in it. Old oil contains moisture, debris from the engine, acids and other impurities. If you’ve changed your oil recently, it should be fine. This procedure incorporates a last-minute oil change, which should be done with the engine warm:
- Fill the empty fuel tank with fresh, stabilized fuel.
- Run the engine at idle for five to 10 minutes to warm it and allow new fuel to replace old.
- With the engine warm, change the oil and (if applicable) the oil filter.
- Run the engine at idle for another five minutes to circulate the new oil. If fogging the engine, remove the air filter and spray fogging oil into the running engine through the air intake. Shut off the engine within 10 seconds of fogging.
- Remove the spark plug(s). Pour a small amount of clean oil into the cylinder(s) or give each a 3-second blast of fogging oil through the plug hole.
- Pull the starter rope or otherwise cycle the engine several times to distribute the oil.
- Reinstall the plug(s) and, if it was removed for fogging, the air filter.
- Make sure the gas tank is just shy of full for storage.
It’s easy to get hung up on the details. Stick to the basics — no untreated gas, a little oil in the cylinders — and your engine will be happy come spring.
Here’s why cleaning matters.
In most cases, when you defer maintenance, your problems won’t compound while the equipment sits. That’s not the case with cleaning. Dirt and debris retain moisture, which promotes corrosion. Grass matted on mower decks is one of the worst offenders. Similarly, sawdust in chainsaws or salt in outboard motors can wreck otherwise sound machines.
Cleaning is also critical before working on the engine. Any time you remove an oil cap or spark plug or air cleaner — all the sorts of things you do when winterizing — you open a direct path to the heart of the engine. Any junk on the outside of the engine risks ending up inside, where it can do serious damage.
But cleaning has clear benefits beyond winterizing. Come spring, dirt will hurt performance and accelerate wear. When debris clogs cylinder fins, for example, it limits the air flow needed to cool the engine. This can lead to overheating and worse. Similar issues arise when air filters, fan guards and radiators become blocked. Dust and dirt also abrade moving parts, like bushings, bearings and brake pads, thereby shortening their useful lives. So it’s worth taking a little extra time to clean your equipment thoroughly and carefully.
When washing your equipment, avoid using pressure washers, which can force water into engine openings. The high pressure can also strip off graphics, poorly adhered paint, and labels with important information like serial numbers. (An exception might be the bottom of mower decks.) It’s better to hand wash with mild soap. Even then, take care not to get water in the air filter.
Why you need to lubricate the cylinders.
In stored engines, oil on cylinder walls and other parts inevitably drains off. This opens them to corrosion and can result in dry parts scraping against each other when the engine is restarted. Adding oil to the cylinders, either in liquid form or via an aerosol, provides a barrier to corrosion and reduces the chance that piston rings will scuff and score cylinder liners.
Guidance differs on the amount of oil to add to cylinders. For small engines, a teaspoon of clean oil per cylinder is plenty. The amount will increase with cylinder size. Consult your manual, but be conservative. After pouring oil into the cylinders, turn the engine over several times to make sure the lubricant fully coats the cylinder walls. Manufacturers generally recommend adding the same motor oil to cylinders that the engine uses. For 4-cycle engines, old hands often substitute 2-cycle oil or Marvel Mystery Oil, a time-tested supplement, on the theory that they burn more cleanly than normal 4-cycle motor oil. Which brings up a good point. Regardless of how it is administered, oil in cylinders will smoke, sometimes heavily, when you first start the engine in spring. It will burn off fairly quickly. Still, many people delay changing spark plugs until after the initial smoke-out of the season to give them a clean start.
An alternative to motor oil for lubricating cylinders is an aerosol fogging oil. It’s easy to use and reaches more of the internal surfaces of the engine. Some boat engines even have dedicated maintenance valves to facilitate fogging. Because different brands have slightly different procedures, follow the directions on the label. Generally, for carbureted engines, they are applied as follows:
- Remove the air filter from the air intake.
- With the engine running, spray fogging oil into the air intake until the exhaust turns smoky.
- After several seconds, shut off the engine.
- Pull the spark plugs.
- Spray a generous blast of fogging oil into each cylinder.
- Cycle the engine several times to distribute the oil.
- Replace the air filter and spark plugs.
As previously noted, some machines will have unique winterizing needs. These are usually covered in detail in operators’ manuals. Here are some areas, in addition to the cleaning, fuel treatment and lubrication procedures above, that need special attention:
- Pressure washers. For machines with an injection system for detergent, flush with clean water. Disconnect and drain the hose and gun. Pull the recoil handle a few times to purge water from the pump, and treat the pump, as directed, with a winterizing conditioner. These fluids, injected through the hose inlet, prevent corrosion, freezing and mineral deposits.
- Garden tractors, four-wheelers, and motorcycles. Months of sitting under load can damage tires and create flat spots. At a minimum, make sure the tires are fully inflated. Better yet, raise the machine on blocks so that the tires are off the ground and the weight is on the frame. For machines with water-cooled engines, you may need to top off coolant tanks with antifreeze.
- Equipment with batteries. Procedures will differ slightly for conventional lead-acid batteries and sealed, maintenance-free batteries. Refer to your operator’s manual or the battery manufacturer for specifics. Typically, batteries should be disconnected, fully charged, (topped off with distilled water if needed) and stored in a cool dry place. Manufacturers often suggest periodic charging – monthly, for example – or the use of an automatic, or “smart,” trickle charger. Clean the battery terminals and grease them lightly to prevent corrosion. The liquid electrolyte in conventional batteries contains sulphuric acid. Avoid spills, and use care when handling.
- Push mowers. Remove caked-on grass from the underside of the deck with a plastic scraper and stiff brush. Wash it, allow it to dry, and treat with a corrosion inhibitor. Empty, wash and dry the grass bag. It’s also a good opportunity to sharpen or replace blades.
- Chainsaws. Remove, clean and oil the bar and chain. Pay particular attention to the guide groove in the bar. Empty the chain-oil tank and wipe it dry. Cleaning carbon from the spark arrestor, a small screen on the exhaust, is an easy item to cross off your maintenance list.
- Outboard motors. Flush with fresh water, if needed, and drain. For cold weather storage, flushing with a marine antifreeze can add an extra layer of protection. Most manufacturers recommend changing both the motor oil and the lower-unit gear case oil, along with oil and fuel-water separating filters. Remove the propeller, clear any tangled fishing line or vegetation, and lubricate the shaft. Grease zerk fittings. Store motors vertically to ensure they drain.
Stow gas-filled equipment away from furnaces, water heaters and any appliance that could ignite fumes. An ideal storage site is dry, dust free, level and secure against theft. It stays above freezing and has a roof that will bear a snow load. Most of us have to make do with something less. For items that must be stored outdoors, a breathable cover will offer some protection and not trap moisture. Gear left outside is an easy target for thieves. Keep it out of sight as much as possible. Chaining equipment to stationary objects, locking trailer hitches, and blocking up trailers with wheels removed can offer some deterrent.
Get a jump on next season
Even if you can’t get to everything on your fall list, there’s plenty you can do in the off season both to get a head start on spring and to make next year’s winterizing job easier.
- Take home small projects or parts that require maintenance; for example, lawnmower blades that need sharpening or chainsaw bars that need filing.
- Order replacement parts. Snap cell phone pictures of bad components, including any part numbers. Or bring the parts home. Sometimes it’s handy to have the physical part to measure. Take pictures of identification labels on bodies and engines. They will give you a record of the model and serial numbers you might need to find replacement parts.
- Gather your storage and maintenance supplies for next year. It’s the best way to avoid store runs, or waiting for deliveries, during the end-of-season crunch.