Storing Outdoor Power Equipment: The Season Calendar
The whole job is fuel. Everything else on a storage checklist — oil, blades, covers, greasing — is worth doing and none of it is what strands the machine next season. Gasoline “begins to degrade in as little as 30 days” (Briggs & Stratton), and a machine stored full of untreated fuel for seven months is the single most common no-start in a repair shop’s spring queue.
What you should actually do with that fuel depends on which of three machine families you own — and the manufacturers flatly contradict each other about it. Briggs & Stratton says top the tank off and treat it. Ariens says drain it completely even if you treated it. STIHL says empty it and run the engine dry. None of them is wrong; they are describing different machines.
Costs verified August 2026. Specifications and storage instructions are quoted from manufacturer guidance read in August 2026 and cited inline. Shop prices are five named shops’ published rates, not a national average.
The storage year by machine family, for a northern US or southern Canadian climate
Storage is a timing problem more than a technique problem. This is the year laid out by machine family, for a northern US or southern Canadian climate — shift it by a few weeks either way for your own first-frost and first-snow dates.
| Month | Mowers & lawn tractors | Snowblowers | Handheld 2-stroke | Pressure washers |
|---|---|---|---|---|
| Aug | In use | — | In use | In use |
| Sep | Last full month of use. Stop buying fuel in bulk now | Pre-season service window opens Sep 15 at some shops | Storm season begins for saws | In use |
| Oct | Final mow, then store. Run the tank low deliberately through the month | Pre-season check: belts, friction discs, shear pins | Trimmers and blowers go into storage after leaf cleanup | Store before first freeze — a trapped-water pump cracks |
| Nov | Stored | In service | Saw stays in service; trimmer stored | Stored |
| Dec–Feb | Stored — shops will not take a mower now | Peak use | Saw in use as needed | Stored |
| Mar | Buy fuel fresh, service window opens Mar 1 | Store it. Snowblower service window closes Mar 1 at some shops | Fresh 50:1 mix — last autumn’s is dead | — |
| Apr–May | In use | Stored | In use | In use |
| Jun–Jul | In use | Stored | In use | In use |
Two rows there are not advice, they are a shop’s published calendar. Farina’s Power Equipment (Watertown, MA) published a service schedule taking lawn mowers March 1 through October 31 only, and snowblowers September 15 through March 1 only. That page was read in August 2026; as of August 19, 2026 the whole farinas.com domain returns a maintenance notice, so it is cited here unlinked and dated rather than pointed at a dead URL. That is a narrower window than most owners assume, and it runs opposite to instinct: the month you finally admit the snowblower needs work is the month nobody will book it in. Storage prep and pre-season service are the same visit, and it has to happen at the end of the season, not the start of the next one.
Where that calendar is wrong for you
Only two dates in that calendar came from a shop, and both are New England’s: Farina’s Sep 15 and Mar 1. The months either side of them are generic northern-climate timing, but those two are the dates a shop will actually hold you to — and they are set for a region that peaks in January. A large part of the snow-belt does not. From NOAA/NCEI’s station snowfall normals (average total snowfall in inches, data through 2023):
| If you are in | Snowiest month | Months averaging ≥1 in | What to shift |
|---|---|---|---|
| Denver, CO (50.5 in/yr) | March (9.7) | Oct–May | Do not store on Mar 1 — you would be storing it the week before the snowiest month of the year. Push snowblower storage to May |
| Salt Lake City (57.6) · Duluth, MN (83.8) · Bismarck, ND (45.9) | December | Oct–Apr | Pre-season service by early October. The calendar above puts the snowblower into service in November; here it is needed in October, a month earlier, so the pre-season check has to move up with it |
| Seattle (10.6) · Philadelphia (20.9) · New York City (28.4) | Jan–Feb | Dec–Mar only | A four-month season. Sep 15 pre-season service is six weeks early, and Mar 1 storage is right |
The Denver row is the one worth sitting with, because it is invisible from the annual figure. Denver averages 50.5 inches a year and Minneapolis averages 50.0 — half an inch apart — but Denver’s season runs eight months and peaks in March, while Minneapolis peaks in January and is done by April. Same annual snowfall, different machine year. If you own both a mower and a snowblower in a long-season western climate, October is the month they overlap: the final mow and the first snow can land in the same fortnight, and the mower has to be put away before the snowblower is needed, not after.
Period of record differs by station — Denver’s runs only from February 2006, after the official station moved — so treat these as long-run averages, not a forecast for any one winter.
The one step the manufacturers disagree about
This is the part worth reading twice, because searching “should I drain the fuel” returns confident answers in both directions and almost nobody explains why both exist.
| Source | What it says, verbatim | The machine it has in mind |
|---|---|---|
| Briggs & Stratton (engine maker) | “Top off the fuel tank before storing” with an alcohol-free stabilizer, which “eliminates the need to drain fuel prior to storage” — keeping fuel fresh “up to 24 months” | 4-stroke engines generally, including machines used year-round |
| Ariens (snowblower OEM) | “Even if the gas has been stabilized, we recommend completely draining your snow blower’s fuel system before storing it away for the season” | A machine that sits idle 4–8 months, by climate — the eighteen-city season-length column runs from Denver’s Oct–May to Seattle’s Dec–Mar |
| Toro (snowblower OEM) | Add treatment, then “empty the fuel system by running the engine dry”, and drain the carburetor’s remaining fuel | Same |
| STIHL (2-stroke handheld) | For 30 days or more: empty the tank, then run the engine “at idle until the engine stops” — “only at idle speed, so there will be lubrication in the system” | Handheld 2-stroke, where the oil is in the fuel |
The reconciling rule, once the four are lined up: the longer the machine sits, the less the stabilizer buys you. Briggs is answering “how do I keep fuel usable,” and stabilizer genuinely does that. Ariens and Toro are answering a different question — “what is in the carburetor’s metering passages in July” — and their answer is nothing, ideally. Ariens is explicit that the problem is not just the fuel going stale but the residue: gas “oxidizes and breaks down over time, creating sludge that can build up inside your snow blower’s fuel tank, carburetor and fuel lines.” A stabilizer that keeps a tank of gasoline combustible for 24 months does not stop a thin film in a jet from drying to varnish.
STIHL’s is the outlier and the reason is mechanical. On a 2-stroke the lubricating oil is dissolved in the fuel, which is why the tank is emptied but the engine is then run — at idle only — rather than simply drained. STIHL also puts a hard shelf life on the mix itself: “never store or use fuel mix older than 60 days”, and “you shouldn’t use the fuel you bought in the fall for next spring. Start each season with a fresh batch of 50:1 two-cycle fuel mix.” Sixty days is shorter than any off-season, which settles the question for handhelds before it is asked.
The procedures themselves — draining a tank, draining a carburetor bowl — belong to your machine’s manual and a servicing dealer. Fuel is the one part of small-engine maintenance where the right instructions are the ones printed for your specific machine.
Why thirty days
Briggs & Stratton specifies a minimum 87 octane with up to 10% ethanol or up to 15% MTBE, and states plainly that E15 “is not recommended or approved for use in small engines” and that “use of unapproved fuels will damage the engine components, which will not be covered under warranty” (fuel recommendations).
One line on that page is worth more than the rest of this article to anyone with a machine still under warranty: “issues that are presented because of fuel degradation are issues that are not covered under the warranty guidelines.” Skipping storage prep does not only risk a repair — it moves that specific repair outside the warranty that would otherwise have paid for it. No cost guide mentions this, and it is the strongest financial argument for a job that takes twenty minutes.
The failure itself is unglamorous. Gasoline oxidizes; the volatile fraction evaporates; what stays behind in the carburetor’s small passages dries to gum and varnish. That is why the machine cranks confidently and never fires, and why the repair is a carburetor clean or a replacement. The replacement is priced at $45–$100 on a walk-behind and $60–$150 on a riding mower in the published ranges (LawnStarter), which price a new carburetor and not a cleaning. The full symptom-by-symptom version is in lawn mower won’t start and snowblower won’t start.
What it costs, done two ways
Here is what those packages are made of. A storage service is priced as a tune-up — and whether the price already contains the oil and the plug it installs varies by shop. Farina’s and CSE bill parts on top, so for those the quoted figure is essentially all labor. Matt’s and HDR name a new spark plug and an oil change inside the package price, so on their two rows the right-hand column below is already paid for rather than an addition.
| Machine | Shop tune-up | The consumables it installs |
|---|---|---|
| Walk-behind mower | $109.99 — Farina’s † | SAE 30, 18 oz: $7.41 · spark plug 692051: $4.79–$7.99 |
| Single-stage snowblower | $95 — Matt’s, plug and oil included · $150 — Farina’s, parts extra | Synthetic 5W-30, 32 oz: $14.99 · plug 802592: $4.99 |
| Two-stage snowblower | $110 — Matt’s · $161 — HDR, both with plug and oil included · $250 — Farina’s, parts extra | Same |
| Chainsaw | $79.99–$129.99 — Farina’s | 2-cycle oil, 50:1 single-dose: $2.58 |
| Trimmer or blower | $79.99–$99.99 — Farina’s | Same |
| Pressure washer | not separately published | Pump saver kit, 4 oz: $10.99 |
Part prices from the Briggs & Stratton store, read August 2026. Shop prices are those shops’ published rates. † Farina’s published price list was read in August 2026. Rechecked August 19, 2026: farinas.com now redirects to a maintenance notice and serves nothing, so these five Farina’s figures are recorded as-read and are no longer independently checkable. They are left in because they were verified when taken, and flagged because you cannot go and confirm them today.
On a mower the two columns are the whole argument — and the mower row is one of the ones where parts really are billed on top. The oil and plug a winterization installs cost $12.20–$15.40 at the engine manufacturer’s own store — that is the mower row’s own SAE 30 at $7.41 plus its own plug at $4.79–$7.99, and no other row’s consumables. The shop charges $109.99 to install them, and bills the parts on top. That is not a criticism of the shops — bench time is what you are buying, and the fixed fees are separate again: across the eight shops priced there, trip charges run from free within five miles to $160 at the edge of a 20-mile radius, and published minimums from $40 to $140, before anything is billed.
Add pickup and delivery and the gap widens sharply. Farina’s quotes $100–$150 roundtrip; Matt’s includes pickup free within five miles.
Batteries are a different job entirely
Battery equipment has no fuel problem and a storage problem nobody warns about, which is that a pack left on a charger all winter and a pack left in an unheated shed both age faster than one stored correctly.
STIHL publishes actual numbers: store a battery between 40% (two green LEDs) and 80% (three green LEDs) charge, at no lower than 14°F and no higher than 122°F, with 50–68°F optimal — and notes that above 86°F, “run time and performance may be reduced.” Unplug the charger and take the pack off it. (STIHL battery storage)
Not full, not empty, and not in the garage in February. Those thresholds are STIHL’s for STIHL packs; EGO, Toro, Ryobi and Greenworks publish their own, and the LED counts differ by brand.
The tune-up that costs more than the failure, and two numbers nobody will confirm
Paying a shop to winterize a cheap mower is arithmetic that does not work. A $109.99 tune-up on a $230–$450 gas push mower, to prevent a $45–$100 carburetor job that may not happen, costs more than the failure it prevents. The same twenty minutes of work with $12–$27 of consumables is clearly worth it. The service is worth its price on a riding mower or a two-stage snowblower — the machines where the repair-or-replace decision is real — and hard to justify on a walk-behind.
Briggs & Stratton gives two different answers for how long stabilized fuel lasts. The storage page says 24 months; the stabilizer page, on the same site, says “up to 3 years.” Both were read in August 2026. Treat any stabilizer shelf-life claim, including the manufacturer’s, as approximate.
The popular explanation for why ethanol fuel goes bad is not published by the four manufacturers this site checked. “Phase separation” — the water-and-alcohol layer settling to the bottom of the tank — is a real and well-documented phenomenon, but the specific saturation percentages that circulate on repair blogs do not appear on Briggs, Toro, Ariens or STIHL’s own fuel pages; they trace back to fuel-industry and patent literature. Not every brand was checked, and one live attribution could not be run to ground: AMSOIL, which sells a fuel additive, credits the “three-quarters of an ounce of water in a gallon of gas” saturation figure to ECHO’s warranty, and ECHO’s own Limited Warranty Statement for the USA and Canada does not mention ethanol at all. This page describes the mechanism only as far as manufacturers state it on documents that could be read, and omits the numbers rather than repeating figures it cannot attribute to a source relevant to your machine.
Before the machine goes away
- Best time of year to buy a mower or snowblower — the other half of the calendar
- What to look for when replacing a snowblower — the full 18-city snowiest-month table, and what neither it nor annual snowfall can tell you about a storm
- Lawn mower won’t start — what the skipped storage prep turns into
- Snowblower won’t start, or the auger won’t turn — the same failure in the other season
- Small engine repair shop rates and fees — trip charges, minimums, and the storage meter that starts after 10 or 30 days
- Is it worth repairing a lawn mower? — if the storage prep was skipped one winter too many
- Buying and seasonal guides — the rest of the calendar, and the replacement guides
Sources: Briggs & Stratton, Storing Your Mower & Outdoor Power Equipment · Briggs & Stratton, The Importance of Fuel Stabilizer · Briggs & Stratton fuel recommendations FAQ — octane, ethanol limit, E15, warranty exclusions · Briggs & Stratton store, oil & lubricants — consumable prices · Ariens, How to Store Your Snow Blower · Toro YardCare, off-season snow blower storage · STIHL, outdoor power tool extended storage tips and STIHL battery storage and STIHL fuel FAQs · Farina’s Power Equipment (Watertown MA) (source offline as of August 19, 2026; figures as read August 2026), Matt’s Small Engine Repair (St. Anthony MN), HDR Small Engine Repair (Traverse City MI) — published service prices and seasonal windows · LawnStarter — carburetor repair range · NOAA/NCEI Comparative Climatic Data, “Snowfall — Average Total In Inches” (data through 2023) — the regional snowiest-month figures
Part and service prices are catalog and published-price-list reads from August 2026 and will move. Service windows are one shop’s published schedule, not an industry standard — confirm with your own shop. Verified August 2026; next scheduled review November 2026.