After the winter season has ended, certain maintenance should be done to insure that your snowthrower will start and operate at the beginning of the next winter season
If your snowthrower has a four-cycle engine, the first thing to be done is to change the engine oil. Used oil will contain some by-products of combustion that may cause some internal engine corrosion over time. Run the engine for 20-30 minutes to warm up the oil before draining. Shut the engine off. Place a pan under the engine oil drain plug, remove the oil drain plug (be careful – the drain plug will be hot) and the used oil will flow down the side of the snowthrower frame into the pan. After the oil has drained out, replace the oil drain plug, tighten the plug and wipe off the oil residue from the frame. Properly dispose of the used oil (there is a used oil disposal tank at the Guilford Transfer Station available at no charge). Now add fresh oil to the engine. This should be a “winter weight” 5W-30 SAE oil. Be sure to fill the engine to the “Full Oil” level. Take care not to over fill. If you use a dipstick to check the level, double and maybe triple check the reading to make sure you don’t get a false high reading. The new oil you poured down the oil fill tube may contact the dipstick as you insert and remove the dipstick to give you a false high oil level reading. During the season it is good practice to check the oil level before starting the engine to make sure there is a proper amount in the engine.
It is also common practice to change the spark plug once a year although you probably could get two years use out of a spark plug in a four-cycle engine. You should find that most spark plugs come properly gaped right out of the package. Take care not to drop a spark plug because that could damage the porcelain coating or change the gap setting.
There are no air filters to change because a snowthrower engine does not use one.
All moving parts should be lubricated to insure free movement later on. Any good quality spray rust preventive lubricant can be used. Water from melting snow and corrosive ice-melting salt can cause moving parts to bind up and stick over time. Be sure to lube the bearing of the rotating auger, chute and chute controls, wheel drive and auger handle pivot pins (on two-stage snowthrowers), both ends of any control cables, idler pulleys on belt drives and the forward & reverse shifting mechanism on two-stage snowthrowers (you may need to remove a few fasteners holding a cover shield on the bottom of the snowthrower to access the shifting mechanism). If not previously done, it is recommended that you remove the wheels from a two-stage snowthrower in order to grease the axles. This action should ensure that you can easily remove a wheel should you get a flat tire; otherwise you might find the wheel rusted to the axle making removal difficult if not almost impossible. And now is a good time to check the tire air pressure; the proper pressure is printed on the sidewall of the tire. All tires naturally lose air pressure and need to be periodically checked.
On a two-stage snowthrower, remove the belt cover located between the chute and the engine. Inspect the belts for wear. Belts that are cracked or frayed should be replaced. In most instances, the wheel drive belt should last many years showing little wear. The auger drive belt is subject to higher work loads. The top of the auger drive belt should be even with the top of the drive pulley. If the top of this belt is worn down to about half the height of the grove in the drive pulley, it is time to replace this belt.
Check the skid shoes located on the sides of the auger housing on two-stage snowthrowers) for wear. Skid shoes worn thin should be replaced. Newer skid shoes often have a reversible design and can be turned upside down to extend their life. Skid shoes should be adjusted so that the auger housing clears the ground by about 1/2″ – 1″ to prevent wearing through the housing bottom. Place pieces of scrap wood or heavy cardboard under the auger housing to make this adjustment. Also inspect for any damaged or missing auger shear pins; replace as necessary and always have spare pins handy. Check the scraper bar located on the bottom of the auger housing.. If worn or the edge is uneven, replace the scraper bar. On some models this part may also be reversible. Check the space between the paddles and the housing on a single-stage snowthrower. If you can easily place your hand between these two parts, then the paddles are worn down and should be replaced.
Don’t forget to check the recoil starting rope for wear. Be sure to check the end of the rope when fully extended for fraying. Replace a worn or frayed recoil rope before it breaks.
Because of how gasoline is formulated today, it has a short shortage life (gasoline can start to degrade in as short a time as one month especially in warm weather). It is strongly recommended that fuel stabilizer be added to any new gasoline you purchase for your snowthrower at the time of purchase. Fuel stabilizer helps keep gasoline usable for about one year but it does not revitalize bad old gasoline. There are other products that may help an engine with bad gasoline to start. It is better to make sure you use good gasoline and avoid all the problems associated with bad gasoline. Old degraded gasoline causes more starting problems than any other single item. Always use a high quality 89 octane gasoline for better starting and performance. If you add stabilized fuel to some unstabilized fuel in your snowthrower, run the engine for about 20 minutes to ensure that the stabilized fuel gets into the carburetor. During the off-season it is a good idea to start the engine and operate all controls every 3-4 months to make sure that the engine will start when you need it next winter and that none of the moving are sticking or frozen. If any parts are sticking, lubricate them.
If you choose to drain the fuel from your snowthrower, it is very important that all fuel be removed from the carburetor. Using a funnel and an empty fuel container, slightly loosen the bolt that holds the bottom of the carburetor bowl in place. You just want to loosen it until fuel starts to tickle out. If you undo the bowl bolt too much, the bowl may come off the carburetor causing some internal parts and/or a gasket to get out of place making re-assembly difficult and possibly causing a leaking bowl. Newer models may have a separate drain plug positioned on the bottom side of the carburetor bowl that you remove. After the fuel has been completely emptied from the fuel tank and carburetor, securely re-tighten the bowl bolt. Take care not to damage the bowl bolt gasket; otherwise it needs to be replaced.