Maintaining and Troubleshooting a Dual-Stage Snow Blower

by Jeff Day

There are two types of snow blowers: single-stage and dual-stage. A single-stage snow blower has an auger that picks up the snow and throws it out a chute. A dual-stage snow blower — also referred to as two-stage — has both an auger and an impeller that acts like a fan. The auger picks up the snow, and the impeller throws it out the chute, so the snow blower can handle more snow more quickly.

This article covers the basics of caring for a dual-stage snow blower. For more detail, download a copy of your snow blower's owner's manual.

Start-of-Winter Care

Before winter arrives — and it has a way of arriving way before you're ready for it — get your snow blower ready for the first snowfal.

Fuel up.

If you have a four-cycle gas-powered snow blower and emptied the gas at the end of last winter, fill the gas tank with gasoline that's less than a month old. Don't fill the tank to the top — leave about 1/2 inch of space for the gas to expand as it warms up.
If you have a 2-cycle snow blower fueled by a gas/oil mix, add a mix of fresh, unleaded gasoline and fresh, clean two-cycle oil, usually in a 40:1 ratio (1 gallon of gas and 3.2 ounces of oil). Don't use boat or automotive oil. Don't use gas blended with ethanol or methanol, which become acidic and can damage your engine if left in the tank during storage.
If you have an electric snow blower, find the extension cord and replace it if it's damaged. To minimize energy loss between the outlet and the snow blower, the cord should be no more than 100 feet long.

Check for storage damage. Even though you put the machine away in good working order, bumps and thumps can happen in the shed during the summer. Work the chute to the left and right and, if it doesn't rotate fully, adjust the chute crank. Check the auger and discharge chute for errant tennis balls, chipmunk nests or other obstructions.

Lubricate. Check the owner's manual for lubrication points and apply the recommended grease.

Start it up. Move the machine outside and let it equilibrate with the outdoor temperature for 10 or 15 minutes. Then start the machine, listen for rattling or vibrating parts and tighten any loose fasteners.

Engage the auger and check whether it's turning. If it's not, the belt is damaged. Check the manual for instructions for replacing it. If you're uncomfortable handling this repair, take it to a service center.

Change the oil, filters and spark plug. To prolong the life of the engine, change the oil after each winter. Your owner's manual includes detailed instructions, but here's the basic procedure:

Warm up the engine for a few minutes so the oil will drain better and then remove the spark plug to prevent accidental starting.
Place a drain pan under the drain plug and remove the drain plug.
When the flow of oil stops, reinsert the drain plug.
Fill with the recommended oil, taking care not to overfill.

Replace or clean the air filter. Replace the fuel filter, if your machine has one.

Before installing a new spark plug, add a few drops of engine oil to the cylinder. While holding a rag over the spark plug hole to prevent patters, pull the starter rope to spread the oil inside the cylinder.

Fill the tires. If your snow blower has pneumatic tires, check their pressure and fill as needed.

Routine Winter Care

Always check the engine oil before you start your snow blower and top off the oil if needed. Look the entire snow blower over for loose, missing or worn parts. and replace parts as needed.
Change the oil after the first 5 hours of use. Snow blower engines have a break-in period, during which metal dust and shavings may come loose and end up floating in the snow blower's oil.
After making the initial oil change, replace the oil once at the end of the winter or after every 50 hours of use, whichever comes first.
Check the spark plug after every 25 hours of use. Replace the plug if it's cracked or damaged; otherwise, brush off any soot with a wire brush and reinsert the spark plug in your snow blower's engine.
After dealing with the plug, lubricate your snow blower's linkages and the gear shaft. Remove the shear pins from the auger assembly and spray a lubricant between the auger shaft and the drive shaft so they don't rust together.

End-of-Winter Care

Unless you get more than 4 feet of snow or you regularly clear block-long sidewalks and driveways, you can do most major maintenance when you put your snow blower away for the summer.

Clean. Rinse grime and salt from the auger and wheels with a garden hose and nozzle. Wipe down the rest of the snow blower with a damp rag and let your snow blower air dry thoroughly before inspecting every surface for rust spots. When you find rust, sand the spot smooth and then spray the sanded surface with an aerosol antirust primer. Let the primer dry and spray on one or two coats of the manufacturer's touch-up paint for your snow blower.

Lubricate. Apply grease between all the moving parts of your snow blower, including the gears that turn the chute, the adjoining surfaces of the moveable hood and the top of the chute, the throttle and clutch levers, and the drive gears and chain. Remove the shear pins and spray lubricant onto the drive shaft before replacing the pins.

Because rust can build up inside the engine during storage, it's a good idea to coat the cylinder with some extra oil. Start by removing the spark plug, then squirt a couple drops of oil through the opening. Pull your snow blower's starter rope several times to distribute the oil.

Remove or stabilize the gas. Gasoline deteriorates over time, making it hard — or impossible — to start an ice-cold engine filled with last year's gas. That's why removing or stabilizing gas remaining in your snow blower after its last use of the winter one of the most important parts of your snow blower's maintenance program.

You have two options:

Run the engine until all the gas is gone. The next time you add fuel, use gas that's less than a month old.
Pour a few ounces of fuel stabilizer into the fuel tank and then run the engine for about 10 minutes to fill it with stabilized fuel.

Change the oil, spark plug and air filter. Change the oil while the snow blower engine is still warm. Put a catch basin under the drain spout and remove the cap. When the oil has drained, replace the cap and refill with oil that meets the manufacturer's specification.

Replace the spark plug with a new one, using the type of plug specified in the Use a gapping tool — available at an auto parts store or the shop that sold you your snow blower — to check the space between electrodes and adjust the height of the spark plug as needed. It's an inexpensive and simple tool, and directions for its use are on the packaging.

Replace the air filter, if your snow blower has one.

Store. Ideally, you should store your snow blower in a dry place indoors. If you must store it outdoors, raise it off the ground on blocks. Many manufacturers recommend putting a cover over the snow blower for further protection — don't cover it with plastic, which traps rust-causing moisture.

Troubleshooting

You can fix most problems with your dual-stage snow blower easily, though the details for each repair vary from model to model. Use the following as a guide to identifying what needs fixing and making a first effort at repairs. Follow the directions in your snow blower's owner's manual when working on your blower.

Engine won't start. Check the safety switch, if any. On an electric-start snow blower, make sure you have plugged in the starter. Next, check whether the choke is on and the engine is primed. Make sure the spark plug is connected and undamaged. Replace old gas with fresh gas.

Snow blower doesn't throw snow. Turn off the snow blower. Check whether the spark plug is loose. If not, disconnect the spark plug to prevent accidental starting before proceeding. Clear the chute with a stick or clean out tool. Check for objects jammed between the auger and auger housing. Adjust the auger belt tension, or replace the belt if it's broken.

Snow blower doesn't work after you run over something. If you run over a stone or large chunk of ice, your snow blower's auger may stop spinning because a safety device called a shear pin breaks. You need to replace broken shear pins to get your blower working again, so always have a couple extra on hand.

Here's what happens. A drive shaft runs through the center of the shaft on which the auger blades are mounted. The two shafts are connected by one or more shear pins, which are cotter pins that snap when the auger encounters too much resistance. This prevents debris from becoming projectiles and also keeps sharp or heavy object from crashing through your snow blower's impelling fan and expelling chute.

Suspect shear pin trouble if you suddenly find it difficult to move your snow blower forward or if snow abruptly slows to a trickle or stops coming out of the chute. Check for a broken shear pin by watching to see if the auger turns while you have someone else run your snow blower.

Before replacing a pin, take the snow blower to a warm spot where you can work comfortably. Disconnect the spark plug and locate the shear pins while consulting the owner's manual for your snow blower. Remove any broken shear pins and slide in new ones; This is usually pretty easy. Double-check for missing shear pins before reattaching your snow blower's spark plug and heading back out into the snow.

Engine runs erratically or surges. Make sure the choke is off. Drain the gas tank and add fresh fuel.

Engine loses power. Make sure the wire is firmly attached to the spark plug. Clear snow and ice off the vent hole in the gas cap.

Snow blower doesn't move. Adjust the clutch cable. Increase the tension on the drive belt following the directions in the owner's manual. Replace the belt if it's broken.

Excessive vibration. Check for loose parts and tighten them.

Jeff Day learned about shear pins when he inadvertently ran the Sunday paper through his snow blower.