Why this skill matters

The generator that fails during a storm failed months before the storm.

Gasoline begins to degrade in 30 days. Ethanol-blended pump gas — what comes out of most US gas stations — separates and absorbs moisture within 60–90 days. A generator stored after last summer's use with a full tank of pump gas has a carburetor full of varnish, a fuel system full of phase-separated ethanol, and possibly rust in the cylinder bore. It will not start reliably in October when the power goes out.

The chainsaw situation is nearly identical. Storm damage cleanup — the fallen limb on the roof, the tree blocking the road, the damaged fence — requires a chainsaw that starts immediately. A chainsaw with a gummed carburetor and a dull chain is worse than no chainsaw, because it creates the expectation of a tool that can't perform.

The maintenance that prevents both situations costs less than $20 per engine and takes 30 minutes. It's done twice a year — before storage and before season. The engines that start on the first pull during an emergency are the ones that went into storage correctly and came out with fresh fuel and a fresh spark plug. The ones that don't are the ones that were put away in a hurry and forgotten.

The one rule that prevents most small engine failures

Never store a small engine with untreated pump gas for more than 30 days. Either drain the fuel system completely (run the engine until it dies from fuel starvation, then run the carb dry), or add a full dose of fuel stabilizer before storage. This one discipline prevents the majority of no-start conditions at the beginning of any season.

What you should be able to do

L1 Household Basic

Treat all stored small engine fuel with stabilizer — or drain completely before storage

Change engine oil at the start and end of each season

Replace spark plugs annually and read a used plug for combustion condition

Clean or replace the air filter on schedule

Fog the cylinder bore before any storage longer than 60 days

Test-run a generator under actual load at least twice a year

Check chainsaw bar oil, chain tension, and chain sharpness before each use

L2 Capable Homeowner

Use carburetor cleaner spray to clear a light varnish buildup

Remove, clean, and reinstall a carburetor bowl and needle valve

Replace a carburetor on a small engine (bolt-on replacement, ~$15–$30)

File a chainsaw chain to restore cutting sharpness

Replace shear bolts on a snowblower auger

Tools and supplies

Keep these on hand before season starts.

Universal — every small engine

Fuel stabilizer (STA-BIL or equivalent). Add to any fuel that will sit more than 30 days. One bottle treats 40+ gallons. Keep it next to the fuel cans.

Ethanol-free fuel. Available at marinas, some gas stations (look for E0), and in cans (TruFuel, VP Small Engine Fuel). Lasts 1–2 years without stabilizer. Worth the extra cost for stored emergency equipment.

Spare spark plugs. Buy the correct type for each engine you own. Cost: $2–$5 each. Keep one per engine in the storage area.

Fogging oil / cylinder spray. For storage. Prevents rust on cylinder walls. One can lasts several seasons.

Carburetor cleaner spray. First-line treatment for a no-start after storage.

Engine-specific supplies to stock

Chainsaw: Bar oil, 2-stroke mix oil (correct ratio for your saw — usually 50:1), round chainsaw file (correct diameter for your chain pitch), spare chains

Snowblower: Shear bolts in the correct size (they break by design — keep 6–10 spares), skid shoe hardware, belt for your model

Generator: Correct oil weight (check manual — usually SAE 30 or 10W-30), spare air filter, spare carburetor if over 5 years old and heavily used

Carburetor replacement vs. rebuild: For most small consumer engines, a direct-replacement carburetor from Amazon or a small engine supplier costs $12–$30 and takes 20 minutes to swap. This is often faster and more reliable than rebuilding an original carburetor with varnish damage. Order by engine model number.

Common problems — what causes them

Start with the fuel — it's the cause 80% of the time.

No-start after storage

Most common cause by far: degraded fuel and gummed carburetor. Old ethanol-blend fuel varnishes the carburetor's tiny jets and passages. Fix progression: (1) try carb cleaner spray into the throat while cranking, (2) drain and replace fuel, (3) clean the carburetor bowl and jet, (4) replace the carburetor. Secondary causes: dead spark plug, stuck choke, seized engine from a dry cylinder bore.

Starts but surges or dies under load

Lean fuel condition — the carburetor jet is partially blocked, delivering less fuel than needed under load. The engine runs at idle when fuel demand is low but stumbles when the load increases. Clean the carburetor bowl and jet. If the engine still surges with a clean carb: the main jet may have a calibrated orifice that needs replacement, not just cleaning.

Hard to pull / won't pull at all

Engine is locked up. Most common cause: hydraulic lock — oil or fuel has accumulated in the cylinder, which is incompressible. Remove the spark plug and crank the engine. If fluid shoots out, you have hydraulic lock. Wipe the cylinder clean, dry, replace the plug, and restart. If the engine is truly seized (won't turn with the plug removed): it's mechanically damaged — consider replacement.

Generator runs but produces no output

The alternator may have lost residual magnetism — a known failure mode on brush-type generators after sitting without being run. Procedure: with the generator running at no-load, briefly connect a 12V battery to the exciter terminals (field flash). This re-magnetizes the rotor. Specific procedure varies by generator model — search for "field flash [your generator model]" for the correct terminal locations. AVR failure is another cause — an inexpensive replacement part.

Chainsaw won't oil the bar

Check the bar oil tank first — it's easily overlooked. If the tank is full and the bar is dry: the oil port on the bar (the small hole that aligns with the oil feed in the body) may be clogged. Remove the bar and clear the port with a thin wire or a burst of compressed air. Running a chainsaw without bar oil destroys the bar in minutes.

Step-by-step maintenance

Two moments per year. End-of-season storage and pre-season service — get both right and the engine starts when you need it.

Generator

— Highest preparedness priority in this category

Pre-season service (L1)

1Fuel: Drain any old fuel. Add fresh ethanol-free fuel with stabilizer, or ethanol-free fuel without stabilizer. Pump gas older than 30 days is already compromised.

2Oil: Check level. Change if dark, if it's been more than a season, or if you're past the hour interval in the manual. Most portable generators use SAE 30 or 10W-30. Never run low — small engines have no oil pressure warning.

3Air filter: Foam filter — wash with soap and water, squeeze dry, re-oil lightly with engine oil before reinstalling. Paper filter — replace if dirty or damaged.

4Spark plug: Replace annually. Thread in by hand first. Gap per the manual (usually 0.028"–0.030" for most small generators — check your manual).

5Test run under load: Connect a real load — a lamp, a box fan, and a small space heater is a good mix (~1,500W total). Run for 30 minutes. This confirms actual output capability and engine performance under realistic conditions. An unloaded test tells you almost nothing.

End-of-season storage (L1)

1Fuel decision: Option A — add a full-dose of stabilizer to the existing fuel, run the engine 10 minutes to circulate treated fuel through the carburetor. Option B — shut off the fuel valve and run the engine dry until it stops from fuel starvation, then pull the cord a few more times to clear the carburetor of remaining fuel. Option B is more thorough.

2Oil change: Change oil before storage — used oil contains combustion acids that corrode engine internals during long storage. Fresh oil goes in; fresh oil comes out in spring.

3Fog the cylinder: Remove the spark plug. Spray fogging oil into the cylinder bore. Pull the recoil cord 3–4 times to coat the cylinder walls. Reinstall the spark plug loosely or cover the hole with a clean rag.

4Exterior: Clean off fuel, oil, and grass debris. Store in a dry location, covered but not airtight (moisture needs to escape). Disconnect the battery on electric-start models to prevent parasitic discharge.

Exercise schedule: Run the generator under load for 30 minutes every 3 months — not just once before storm season. This keeps fuel fresh, confirms reliability, and reveals developing problems before they occur during an outage.

Chainsaw

Before every use (L1)

1Bar oil level: Check before every single use. Fill if below ¼. Running the saw without bar oil destroys the bar in under 5 minutes. The bar oil tank is usually a small separate reservoir from the fuel tank.

2Chain tension: The chain should have approximately ¼" of sag at mid-bar when the bar is horizontal. Too tight — chain won't move freely by hand, overheats quickly. Too loose — dangerous derailment risk. Adjust at the chain tensioning screw on the side panel.

3Sharpness check: A sharp chain cuts with minimal downward pressure and produces chips. A dull chain requires significant pressure and produces sawdust. Sawdust means the chain is dull — file it or have it sharpened before a serious job.

4Fuel mix: Most chainsaws use 50:1 (gasoline to 2-stroke oil). Some older saws use 40:1. Check the owner's manual or the fuel cap label. Wrong ratio: too rich = carbon buildup, too lean = engine seizure. Use fresh mix — don't use 2-stroke mix older than 30 days.

End-of-season storage (L1)

1Run the saw until it stops from fuel starvation — no residual fuel in the carburetor to gum. Drain the bar oil tank as well.

2Remove the bar and chain. Clean bar groove of sawdust and pitch with a flat tool. Lubricate the bar groove with bar oil before storage. Soak the chain in bar oil overnight, then drain.

3Clean the air filter and cooling fins. Sawdust packed around the engine causes overheating.

4Fog the cylinder bore. Store with the guide bar cover on. Check the chain sharpness before the next use — dull chains are a safety hazard as much as a performance issue.

Snowblower

1Shear bolts: Keep 6–10 spares in the correct size. Shear bolts are designed to break when the auger hits ice or a buried object — protecting the expensive gearbox. A snowblower that hits ice and stops mid-driveway needs its shear bolts replaced in the cold. Have the spares and know how to install them in 5 minutes.

2Pre-season (fall): Fresh treated fuel, oil change, check the impeller and auger for damage, inspect belts for cracking, lubricate auger and chute pivot points with silicone spray.

3End-of-season (spring): Treat fuel or drain completely. Change oil. Lubricate all moving parts. Store with the chute in its lowest position to reduce spring stress on the cable.

Carburetor cleaning L2

1Spray method (try this first): Remove the air filter. Spray carburetor cleaner directly into the carburetor throat while cranking the engine. This often dissolves light varnish and gets a stored engine running. If it starts and runs rough, let it run 10 minutes — the engine's own fuel flow often clears remaining gum.

2Bowl cleaning: Remove the carburetor bowl (single bolt underneath). Inside is the float, needle valve, and main jet. Spray all passages with carb cleaner. Clear the main jet orifice with a single strand from a wire brush — never a drill bit, which enlarges the orifice and alters the fuel/air ratio.

3Replacement (fastest fix): If the carburetor is heavily varnished or the above steps don't resolve the problem, replace the entire carburetor. Search "[engine model] carburetor" on Amazon — most replacement carbs for small engines are $12–$30 and bolt on directly. This often takes less time than a full rebuild.

Fuel storage rules

The rules that prevent most small engine failures.

Pump gas (ethanol blend)

Degrades in 30 days. With stabilizer: 1–2 years. Never store equipment more than 30 days without treating or draining. The phase separation (ethanol absorbing water and separating from the fuel) is not visible and cannot be reversed by adding more stabilizer after the fact.

Ethanol-free fuel

Lasts 1–2 years without stabilizer. Worth the extra cost for stored emergency equipment. Available at most marinas (recreational boat fuel), some stations selling ethanol-free under the E0 label, and in cans (TruFuel, VP Small Engine, Husqvarna XP). Use ethanol-free for all chainsaws and small engines if possible.

Storage quantity

NFPA 30 limits residential fuel storage to 10 gallons indoors and 25 gallons in a detached structure. Store in approved containers (red = gasoline) in a detached, ventilated structure away from ignition sources. Date cans when filled. Rotate fuel — use old stock in the lawn mower, replace with fresh for stored emergency equipment.

Emergency and disruption application

When these engines are the variable.

Power outage — generator

A generator that won't start on the first pull of a multi-day outage isn't just an inconvenience — it's a morale problem on top of the practical one. The households with running generators during extended outages are almost always the ones whose generators were exercised in the 3 months before. Know your generator's wattage capacity and what it can realistically power — refrigerator + lights is about 1,200W, add a space heater and you're at 2,700W.

Storm damage — chainsaw

A fallen limb on the roof, a tree blocking the driveway, a fence knocked down across the road. A chainsaw that starts immediately can address these in 30–60 minutes. One that needs carburetor work in the cold and wet, while the problem gets worse, is a different situation. Maintenance before the storm converts the chainsaw from a maybe into a reliable tool.

Fuel supply disruption

During extended regional emergencies, gas stations run out and supply chains take days to restore. Having 5–10 gallons of treated, stable fuel in approved storage (in a detached structure, per NFPA 30) provides a buffer during the first 48–72 hours when supply is most constrained. Ethanol-free fuel with stabilizer can be rotated annually and kept without degradation.

Mandatory section

Repair or replace — and when to call a shop.

Small engine repair shops charge $75–$150/hour. Many repairs cost more than the equipment is worth. The decision framework matters more than any specific repair list.

Repair makes sense when

It's a carburetor, spark plug, air filter, or fuel issue — homeowner-solvable
The equipment is relatively new and otherwise in good condition
The repair cost is under 30% of replacement cost
The replacement carburetor or part is available and inexpensive

Replacement usually makes sense when

Engine is seized, scored, or has low compression (internal mechanical damage)
Professional repair cost exceeds 50% of replacement value
Equipment is 10+ years old with recurring issues
Parts are unavailable or backordered for months

Always take to a professional: fuel leak anywhere near heat

A fuel leak at a carburetor gasket, fuel line, or tank near a hot engine is a fire risk. Don't attempt to operate the equipment. Take it to a shop or, if the equipment is old and the repair cost is high, replace it.

Generator: AVR, stator, or rotor failure

An automatic voltage regulator (AVR) failure causes the generator to run but produce no clean power or no power at all. AVR replacement is a $20–$50 part and a 30-minute job on most generators — but diagnosing it correctly requires a multimeter and knowledge of how to test the components. If you're not comfortable with this diagnosis, a small engine shop can do it quickly.

The 50% rule and timing

If the repair cost exceeds 50% of a new equivalent unit, replacement is usually the better long-term decision — especially for equipment that's 7+ years old. Exception: if you need the equipment immediately during an emergency and no replacement is available, any working repair is better than a new unit that arrives in 3 days.

Practice project

Do this today: run the generator under load for 30 minutes.

Time: 45 minutes total. Cost: fresh fuel (~$5). Outcome: confirmed reliability, any issues found while there's time to fix them.

1.

Get fresh fuel — ethanol-free if possible. If using pump gas, add stabilizer now. Check the oil. If it's dark or you don't know when it was last changed, change it before running.

2.

Bring it outside — away from windows, doors, and any enclosed space. Never run a generator indoors or in a garage, even with the door open. Carbon monoxide kills in minutes in enclosed spaces.

3.

Connect a real load: a floor lamp, a box fan, and a portable electric space heater. Run for 30 minutes. Note: surging (speed hunting), smoking, tripping the breaker, or output that dims lights.

4.

If it doesn't start: follow the troubleshooting sequence — fresh fuel first, then carb cleaner spray, then spark plug. Note what you found and address it now, not during the next outage.

5.

Record the test date in the home maintenance binder. Set a calendar reminder for 3 months from now — next test. Add a note on what load you ran and any observations.

If you don't own a generator: Consider a lithium portable power station (500–2,000Wh) — no fuel to degrade, no maintenance, no exhaust, safe indoors. Powers phones, laptops, CPAP, fans, and LED lighting for 8–48 hours depending on capacity. Charging options include wall outlet (before the outage), solar panel, or vehicle 12V port.

Recommended resources

Books, resources, and the credential.

Books

Small Gas Engines (Alfred Roth) — the standard vocational textbook used in community college small engine programs. Covers four-stroke and two-stroke theory, carburetion, ignition, and hands-on diagnosis. The reference book for serious homeowners.

Owner's manual for your specific engine — the most useful single document for any small engine. Contains the correct oil weight, spark plug, gap, fuel mixture, and maintenance schedule. Download as PDF from the manufacturer if the paper version is lost.

Free resources

YouTube — Paul's Garage: The best free resource for small engine diagnosis and repair, with real videos on gummed carburetors, no-start diagnosis, and generator maintenance.

Community college outdoor power equipment / small engine programs — see your state's Learning page for local options.

Cooperative extension offices often host farm and equipment maintenance workshops seasonally.

The credential

Small engine repair certificate — community colleges offer 1–2 semester programs covering four-stroke and two-stroke engines, carburetors, ignition systems, and diagnosis. Often available as evening or weekend continuing education.

Equipment & Engine Training Council (EETC) certification — the industry credential for outdoor power equipment service technicians. Multiple levels covering increasing diagnostic complexity.

No certification is required for fuel treatment, spark plugs, oil changes, air filters, or carburetor replacement as a homeowner.