Pull the crank . . . 
and it starts and runs

by John Howle

When we pull the cord on a small engine, we want it to crank and we want it to run smoothly. Regular maintenance keeps the engines running, but there are a few inside tricks that will keep your small engine out of the shop and in the fields this summer.

Most of the small engines powering your tiller, generator, ATV and lawnmower are generally four-stroke motors. This means the gas and oil are housed separately. Weed trimmers and chainsaws are two-stroke or two-cycle motors using oil and gas mixed together in a certain ratio. In two-cycle engines, the oil mixed with the fuel lubricates the parts of the engine as it passes through the engine during the combustion cycle. On four-cycle engines, the oil pumps or oil sumps lubricate the engine and the fuel is not pre-mixed.

Fix the Fuel

 Randall Shierling, owner of H.L. Shierling & Son Lawn and Garden, has kept engines running smoothly for his customers for the last 47 years. He is located in the heart of the timber harvesting industry in Fruithurst where his customers’ livelihood depends on keeping small engines like chainsaws, weed trimmers and lawnmowers running. Shierling said, with the higher levels of ethanol in the gas today, users need to exercise a little more maintenance to keep their engines running smoothly.

Shierling explained the best way to guarantee high-quality fuel is to put a fuel additive into each tank of gas. This fuel additive should contain a fuel stabilizer and an additive to counteract the effects of ethanol fuel.

"I use and recommend Startron in the shop and it contains both fuel stabilizer and ethanol cure," Shierling said.

There are other brands of fuel stabilizer and ethanol cure on the market if you simply Google the products. Shierling warned that it often takes no more than 30 days for modern fuels to break down; ultimately causing carburetor damage to small engines.

Once you’ve taken care of the fuel, you can focus on the other important factors for engine performance. The basics involve checking the oil level and making sure the air filter is clean.

"That air filter has to be able to breathe just like a person would," Shierling explained. "If the air filter is clogged or dirty, the engine has to work harder to run and this can cause more stress on other parts of the engine as well."

Each season, you should perform a tune-up on your small engine. A tune-up for a small engine basically means making sure the engine can breathe, spark, ignite and run with clean oil serving as a lubricant. In other words, replace the air filter, spark plug, oil filter and oil. While the engine is warm, change the oil and filter if the unit has one. Finally, clean the engine thoroughly. This will prevent debris from entering the fuel or oil, and it will show any leaks or potential problem areas in the engine.

Finally, the easiest maintenance is to clean the unit after each use. If all grass, dirt and trash is removed, any potential leaks can be revealed. Save a few minutes after each use for cleaning of your small engine implements.

"If you are not going to use the equipment very much, I would always stress burning fuel with stabilizer and ethanol cure in it," Shierling suggested. "If you are going to store your implement like chainsaw or weed trimmer for long term, you can run the fuel completely dry in the tank and lines by letting the engine run until it shuts off due to lack of gas.

"We are told during our training sessions that you can store the unit with the gas tank full of gas combined with gas stabilizer and ethanol cure. Let the engine run a while. When you turn it off, there will be stabilizer and ethanol cure remaining in the lines so the solvent action of the ethanol won’t break down the plastic and rubber components in the carburetor."

When you are ready to store the unit and it is a four-cycle engine, change the oil and filter because old oil in the engine can deteriorate seals and gaskets. Once you’ve filled the unit with new oil, run the engine for a few minutes to bathe the internal components.

It is best to follow the manu-facturer’s recommended scheduled maintenance when the unit is new so the practice will be a habit. Finally, take the time to schedule seasonal tune-ups, and your unit should fire up and be ready to go each spring. Use this small engine survival guide to keep your equipment running smoothly this season. Visit www.briggsandstratton.com and click on "Support" to find more useful information on maintenance of your four-cycle small engine implements. For more information about two-cycle engines, visit www.stihlusa.com.