Part of our complete Small Engine Troubleshooting Guide.
Work through it in the order below rather than jumping to the carburetor, because two of the commonest causes cost nothing to rule out. And do the whole thing now, in October, not on the morning you need the machine. A snow blower is the one piece of equipment where a shop queue and a snowstorm arrive at the same time.
Two safety rules that matter more than anything below. Never start or run a snow blower in a closed garage — these engines make carbon monoxide and a garage fills faster than people expect. And never put a hand into the chute or near the impeller to clear it. Shut the engine off, take the key, wait for everything to stop turning, and use the clearing tool.
1. Storage Is the Fault, Not Wear
Most snow blowers that will not start have barely any hours on them. The engine is fine. What is not fine is the fuel that was left in the tank and the carburetor when the machine was pushed into the corner in spring, because pump gasoline does not keep. Over a summer the light part evaporates and what stays behind turns to a sticky varnish.
That varnish settles in the float bowl and dries in the main jet, which is the smallest hole in the whole machine. The engine then cranks willingly and gets nothing it can burn. Our notes on ethanol gas and small engines explain why the fuel behaves that way and what to do with the machine in spring instead.
2. Fuel: Valve, Tank and Carburetor
Start at the top of the fuel path and work down. Four checks cover nearly all of it:
- The fuel shutoff valve. If it was closed for storage, it is still closed. This is the single most embarrassing no-start and it is common.
- What is in the tank. Fuel that smells sour or like old varnish rather than like gasoline will not run the engine. Drain it and put fresh in.
- The fuel cap vent. A blocked vent lets the tank pull into a vacuum, so the machine starts, runs a short while and dies.
- The bowl and the jet. If fresh fuel does not fix it, the carburetor needs cleaning rather than coaxing. That is a bench job and it is the repair most of these machines actually need.
3. The Starting Sequence People Get Wrong
Snow blower controls are unforgiving in the cold because there are more of them than on a mower: a fuel valve, a choke, a throttle, a primer bulb and usually an ignition key or toggle. Miss one and the machine behaves exactly like a broken one.
Cold and correct is: valve open, key in, throttle to fast, choke fully closed, two or three presses of the primer, then pull. Warm and correct is: no primer at all and little or no choke. The mistake is reaching for the primer again after it fails to catch, which puts far more fuel into an engine that is already wet.
4. Spark, Keys and Interlocks
If it has been primed repeatedly it is probably flooded. A flooded engine smells strongly of fuel, and the plug comes out wet. Dry the plug, open the choke fully, and pull it through several times before trying again.
While the plug is out, look at it. Black and sooty, oily, or with a cracked insulator all mean it should be replaced rather than cleaned, and a plug lead that has worked loose is worth pushing home firmly. After that check the ignition key or toggle is actually in and on, and that any kill switch or interlock is seated — the same class of fault as the safety switches in our guide to a zero-turn that will not start.
5. Electric Start After a Summer Off
On a model with a 120-volt starter, the machine is only as good as what you plug it into. Test the outlet with something else, reset the GFCI, and check the cord end has not been crushed or chewed over the summer. If the starter hums or clicks but does not spin the engine, stop using it in long bursts; these starters are made for short attempts.
Battery-start models have a simpler problem. A battery left all summer without a charge often will not come back, and no amount of cranking will prove otherwise. Try the recoil starter instead — if it starts on the cord, the engine is fine and the fault is purely electrical.
6. It Starts but Will Not Throw Snow
Worth separating clearly, because it is a different repair. The engine and the auger drive are two systems joined by belts. An engine that runs well while the auger sits still has a belt that has stretched, slipped off or glazed, a sheared shear pin, or a gearbox problem — none of which is an engine fault.
Shear pins in particular are designed to break, so that a chunk of ice or a newspaper stops the auger instead of wrecking the gearbox. Our guide to snow blower service before winter covers belts, pins, skid shoes and the scraper bar in the order they come apart.
Reading the Symptom
WHAT IT DOES WHEN YOU PULL IT
| What Happens | What It Usually Is |
|---|---|
| Cranks easily, never fires, no smell of fuel | Fuel valve closed, empty tank, or a jet blocked with varnish. |
| Strong smell of gas, will not fire, plug wet | Flooded by over-priming. Dry the plug, choke off, pull it through. |
| Fires, runs a minute, dies | Blocked cap vent or stale fuel feeding a partly blocked carburetor. |
| Electric start clicks or hums, recoil starts it fine | Outlet, cord or battery. The engine itself is not the problem. |
When to Call the Shop
Fresh fuel, an open valve, a new plug, a dried-out cylinder and a clean cap vent are all driveway jobs, and between them they start a good share of the machines that come in every November. If the machine has been sitting on last winter's fuel, assume the carburetor is the problem and plan around that rather than hoping.
Bring it in when fresh fuel changes nothing, which means the carburetor needs cleaning properly; when the engine starts and the auger will not turn; when the electric starter is dead and you would rather not fight it in the cold; or when it ran last winter and then quit mid-storm. A machine that will not run is also exactly what our pickup and delivery is for, since a snow blower is nobody's idea of an easy load.
Snow Blower No-Start FAQ
Why won't my snow blower start after sitting all summer?
Nearly always the fuel. Gasoline left standing for months leaves varnish in the bowl and the jet, so the engine cranks but gets nothing usable. Fresh fuel and a carburetor clean fix most of them.
How many times should I press the primer bulb?
Two or three on a cold engine, and none at all on one that has already been running. Extra presses flood it, and a flooded engine smells strongly of gas and will not fire no matter how hard you pull.
My snow blower runs but the auger won't turn. Is that the same problem?
No. The engine and the drive are separate systems, so a machine that runs well and will not throw snow has a belt, a shear pin or a gearbox fault rather than an engine fault.
Can you service a snow blower in Richmond, KY?
We do, and October is the time to do it rather than the morning of the first storm. Carburetors, augers, belts, shear pins and electric start across Madison County, with pickup and delivery and a firm quote before any work begins: (859) 661-8877.
Snow Blower Not Starting? Get a Firm Quote.
Honest diagnosis, fair pricing and fast turnaround from Turf & Trail Small Engine Repair in Richmond, KY — and the queue is a lot shorter in October than it is after the first snow.
We handle carburetor and fuel system work, augers, belts and shear pins alongside lawn mower repair and generator repair, and our pickup and delivery in Madison County saves you loading it. If the machine is running but something else is wrong, start with snow blower service before winter. Serving Richmond, Berea, Waco and Kirksville.
Call (859) 661-8877