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Snowblower won't start

The first storm of the season is the worst time to find out — but most no-starts are fuel that sat all summer or a missed cold-start step, not a broken machine.

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Select anything that matches and the checklist below reorders to fit. Not sure? Skip it.
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In Canada, stale gas is the first thing to rule out on a snowblower that sat all summer. Open the fuel cap and smell: fresh gas is sharp; stale gas smells sour, like varnish. If it's last season's fuel, drain it and refill with fresh gas plus stabilizer before you spend a dollar on parts — it's the most common cause, and the cheapest fix on this page.

Ranked from real-world failure data. The order updates as you select what you’re noticing above.

Likely causes, in the order to check them

Showing the typical order
Beginner-friendly Doable, with care Safety-critical Call a pro

visibilityHow to check

  1. Open the fuel cap and smell. Fresh gas smells sharp; stale gas smells sour — like varnish or old paint thinner.
  2. Look into the tank if you can: stale gas runs darker and may look cloudy or separated.
  3. If it's been in there since last winter, treat it as stale even if it smells borderline. Draining and refilling costs less than any part you'd replace by guessing.
buildNo tools schedule5 min

handymanHow to fix it

warning Fuel work happens outsideGasoline vapour is heavier than air and drifts to ignition sources you forgot about — a garage heater, a water-heater pilot, a woodstove. Drain and pour fuel outdoors only, engine cold, with nothing burning nearby, and wipe up drips before you pull the cord. If draining the tank feels like more than you signed up for, a small-engine shop will do it as part of a pre-season tune.

Drain last season's gas outdoors into an approved container, refill with fresh fuel, and add stabilizer to every can of small-engine gas from now on.

  1. Work outdoors (or with the machine rolled well out of the garage), engine cold. Siphon or drain the tank into an approved fuel container — many carburetors also have a bowl drain screw that lets the last of it out.
  2. Refill with fresh gas, and add fuel stabilizer to the can at fill-up. Buy amounts you'll use this season.
  3. Take the stale gas to your municipal household-hazardous-waste depot — not the drain, not the snowbank.
  4. Open the fuel shutoff, give fuel a minute to reach the carburetor, then run the full cold-start routine. If it still won't fire once fresh fuel has had a chance, move to the spark plug.
schedule30 min savings$5–20
Fuel stabilizerAny major brand; add to every can of small-engine gas at fill-up

visibilityHow to check

  1. Reset and do the whole routine deliberately: fuel shutoff OPEN, ignition key in (and any stop switch to RUN), throttle to fast.
  2. Choke to FULL — a cold engine needs the rich mix even if it feels excessive. Skip the choke only when the engine is already warm.
  3. Press the primer bulb the number of times the manual says — usually two or three, a couple more in deep cold. Then pull or hit the electric start.
  4. When it fires, let it run a few seconds, then ease the choke to half and off as it warms. If it fires and dies the moment the choke comes off, run it on choke a little longer — and if it only ever runs WITH the choke on, fuel delivery is restricted: look at the carburetor next.
buildNo tools schedule5 min

visibilityHow to check

report Key out, plug wire off — and hands out of the auger, alwaysBefore any work on this machine, shut it off, take the key out, and pull the boot off the spark plug so nothing can fire while your hands are on it. And the rule that outranks every other on this page: hands and feet never go into the auger or chute, even with the engine off — a jammed impeller can hold stored tension that releases without warning. Clear jams with the clean-out tool only.
  1. Check the obvious first: press the rubber boot firmly onto the plug. A boot knocked half-off during summer storage means no spark.
  2. If it still won't fire, pull the boot and remove the plug with a plug wrench or deep socket (commonly 3/4 in. or 13/16 in.). On many snowblowers the plug hides under a snow hood or cover panel.
  3. Read the tip. Light tan-grey means healthy. Sooty black means fouled. Wet with gas means flooded — leave the plug out for 15 minutes to dry, and don't crank it while you wait.
  4. Check the gap against your engine manual and look for a rounded, worn electrode. When in doubt, a new plug is $6–12 and removes the question.
buildspark plug wrench schedule15 min

handymanHow to fix it

Replace a fouled plug with the exact type for your engine, gapped to spec — or clean and re-gap the old one in a pinch. A new plug is $6–12 and removes the doubt.

  1. With the key out and the plug wire off (see the gate above), remove the old plug and buy an exact match — the code is printed on the ceramic, or look up your engine model.
  2. Check the gap against the manual with a gap gauge; adjust gently on the side electrode only.
  3. Thread it in by hand until snug — small engines have soft aluminum heads — then a firm quarter-turn with the wrench. Press the boot on until it clicks.
  4. If a new plug fouls again within a few outings, something upstream (rich carburetor, stale fuel, choke left on) is the cause to chase next.
schedule15 min savings$6–15
Snowblower spark plugMatch the code printed on the old plug's ceramic, or look up your engine model number

visibilityHow to check

  1. Follow the fuel hose down from the tank: the shutoff is a small lever or dial where the hose leaves the tank (not every model has one).
  2. Set it to OPEN — on lever types that usually means in line with the hose. If it was closed, give the fuel a minute to reach the carburetor, then redo the cold-start routine.
buildNo tools schedule2 min

visibilityHow to check

  1. Do this outdoors, engine cold. Remove the air-intake cover to expose the carburetor throat (on snowblowers it's often right behind the primer bulb housing).
  2. Give one short burst of starter fluid into the intake, refit the cover loosely, and try to start it.
  3. Fires for a second or two, then dies: spark is fine and fuel isn't arriving — the carburetor is the prime suspect after a summer of stale gas (with the fuel shutoff double-checked first). No fire at all sends you back to the spark plug.
buildstarter fluid schedule10 min

handymanHow to fix it

report Fuel, springs, and tiny parts — in the coldCarburetor work means open fuel: outdoors, engine cold, key out, plug wire off, nothing burning nearby. It also means small springs and gaskets that vanish into the snow, handled with cold fingers. If any of that feels fiddly, stop guilt-free: a small-engine shop does this all day, and a pre-season tune with a carb clean typically runs $80–180 — cheap insurance against being the only house on the street not cleared after the storm.

Clean the carburetor: drain the bowl, spray the jets and passages with carb cleaner, and reassemble — or hand the machine to a small-engine shop for a pre-season tune that includes exactly this.

  1. Outdoors or with the machine rolled out of the garage, engine cold, key out, plug wire off, fuel shutoff closed (or tank drained). Put a rag under the carb — some gas will escape.
  2. Remove the float bowl (usually one bolt underneath). Photograph everything before it comes apart — cold fingers lose small parts.
  3. Spray carb cleaner through the main jet (often inside that bowl bolt) and the visible passages until they run clear. A single strand of wire clears a stubborn jet; never drill one.
  4. Reassemble with the gasket seated, open the fuel shutoff, refill with fresh fuel, and start it. If it runs only on choke or surges, the deeper passages are still varnished — that's the point where the shop earns its fee.
schedule60 min savings$8–25
Carburetor cleaner sprayAerosol carb/choke cleaner with the straw nozzle
sort

Why the list is in this order

We don’t sort by likelihood alone. We sort the way a good, honest tradesperson thinks: rule out the free, safe, common causes first. That’s why the cheap checks outrank the expensive repairs — and why anything dangerous gets a hard stop instead of a pep talk. The order exists to save you money, not to sell you anything.