The snowblower engine needs gas, compression and spark to start, so if your snowblower isn't starting, focus on those. First, make sure the gas in the tank is fresh; older gas can form gummy deposits that interfere with starting. Gummy deposits clog the carburetor so clean or replace the carburetor if it's clogged. Check the fuel line and fuel filter and replace those components if clogged.
Another easy thing to check is the spark plug-if the spark plug is cracked or has a sooty electrode, replace it. Check the stop switch and replace it if it isn't allowing the spark plug to get current. A good engine tune-up that includes an oil change may help the engine start.
A failed rewind starter or electric starter won't spin the engine so replace those components if broken. For a quick compression test, remove the spark plug, cover the cylinder hole with your thumb and pull the starter rope. If you don't feel air against your thumb, you may need to adjust the valve lash. A damaged piston, piston rings, or cylinder could cause a compression problem—and it might be time for a service technician. Watch our snowblower engine won't start video for more troubleshooting tips.