Small Engine Start Up for Lawnmowers, Trimmers, Snowblowers, and Leaf Blowers

lawn mower and gas can on the grass
What You'll Need
Motor oil
Oil can
Spark plug or adjustable wrench
Gasoline storage can
Detergent and clean water

Is it time to put away your snow blower? Want to make sure the engine will start next fall when you need it? Small engines that are just put away once their season is over (snow blowers, lawn mowers), can be cranky and hard to start next season. Six months after you just left them in the garage or shed is not the time to think about what you could have done. Making sure that engine will start next season isn't hard and it'll probably take you less than an hour. Come next season I know you'll agree it was time well spent. Here’s all you have to do to make sure that the engine starts.

Step 1 - Start by Draining the Oil

If the engine hasn't been running for a while, start it and let it warm up. Once its warm shut it off and drain the oil from the crankcase. It's best to do this while the engine is still warm so impurities and tiny particles suspended in the oil drain right out. Now, refill the engine with clean oil - probably 10W30 but be sure to use whatever your owner's manual specifies.

Note: You only need to drain the oil in 4-cycle engines, (motor runs on straight gasoline). 2-cycle engines (where the oil and gasoline are mixed before use) don’t have a crankcase, and the oil and gasoline mixture together lubricates the engine.

Step 2 - Clean the Air Filter

two air filters

Most small engines have a plastic foam air filter that is impregnated with oil to catch dust. Over time the filter gets clogged with dust and stops filtering. Take out the air filter and clean it by washing it in warm water and dish detergent. Dry it by wrapping it in a paper towel and squeezing it, then re-coat it with clean oil and replace it.

Step 3 - Drain the Gas Tank

Once the engine is cool, you want to drain the gas tank. There's usually a small rubber hose attached to the bottom of the tank held in place by a pressure clip. Use a funnel and drain the gasoline into a tin can or gas storage can. Once the tank is empty, start the engine and let it run on the gas remaining in the carburetor until the engine stops, out of fuel. By running the engine out of fuel, you eliminate the chance that the gas in your carburetor and fuel system will evaporate and "varnish" over time. A carburetor with gas residue (varnish) in it won’t work properly and you'll likely need to remove and clean it for your engine to run properly next season.

An alternative to running your engine out of fuel is to fill the tank right up with gas and add a "gasoline stabilizer" (available at home and automotive stores), that's formulated to stop gas from varnishing and plugging your fuel system. The downside to this approach is you need to store your engine with a full tank of fuel and by next season; the gas will be six months old.

Step 4 - Remove the Spark Plug

snow blower

Use a spark plug wrench or if you don't have one, an adjustable wrench to remove the spark plug. Apply slow easy pressure, don't jerk on it, and remember, spark plugs can break.

Once the plug is out of the engine, use an oil can to put a few squirts of oil right into the spark plug hole. Now, without replacing the plug, pull slowly on the starter cord to turn the engine over a few times. This will spread the oil you just squirted in onto valves preventing any rust from building up inside the motor.

While you've got the plug in your hand, check the tip. If it’s pitted or corroded you should replace it, but if it's just dirty, you can clean the gap and put it back into the engine - hand tight. If you decide to replace the spark plug take the old one with you to the store to make sure you get an exact replacement - all spark plugs aren't the same.

That's it. All that’s left to do is store your snow blower/lawn mower away from weather and animals for the season. Come next year, tighten the spark plug, fill the tank with fresh gasoline and start it up. Don't be alarmed if the oil you squirted into the cylinder head makes the exhaust smoky for a few minutes until it's burned up.

Isn't it nice to have an engine that starts when you need it?

Murray Anderson is an experienced freelance writer. His work has covered a wide range of topics, but he specializes in home maintenance and how to's. He has more than 500 articles published on the web, as well as print magazines and newspapers in both the United States and Canada.