Engines Under Pressure
Talk about pressure. Day in and day out, engines work hard to maintain a rigorous pace – spark plugs fire, flywheels turn, fuel moves through and pistons stroke. And, what thanks do they get? Sure, they get fresh fuel refills and an occasional oil change – but, where’s the love?

All right, most contractors really don’t have much time for love, per se. But how about a little give and take – a hard day’s work from the engine, some preventative maintenance steps in return to keep it looking good and running fine.

Understanding preventative engine maintenance will help operators avoid downtime and stay efficient. Here are some engine maintenance tips to ease the pressure of starting a sufficient preventative maintenance program.

Daily Pressure

Although it is often the most overlooked step, daily maintenance is usually the easiest and quickest to perform. To prevent serious problems, most know that checking the oil before each use is a necessity. However, many do not know that in small, air-cooled engines, oil serves a dual purpose.

Because an air-cooling system does not use a liquid coolant, it often is assumed that air alone acts as the cooling medium. Fuel and the lubrication systems also help cool these types of engines. For this reason, it is equally important to check the oil on air-cooled engines, even if the manufacturer does not claim it is needed.

Checking the condition of the air filter is another important daily maintenance practice. A clogged, wet or damaged air filter can lead to a loss in power and shorten the life of an engine by allowing dirt or water into sensitive areas.

One of the most basic daily maintenance steps is cleaning the engine. Not only does cleaning the engine get rid of water spots and potentially harmful dirt, but it also helps prevent rust and gives the operator a chance to check the engine for leaks, loose parts and damaged components. Replace anything that is damaged, and tighten loose parts that could vibrate and potentially harm nearby components.

A greasy or dirty engine should be cleaned by spraying it with a non-petroleum-based degreaser. Wait for the solvent to start breaking down the dirt, then wipe it clean with a cloth or soft brush. The engine should always be warm, not hot, when it is being cleaned. Warm water at a low pressure can be used to rinse the engine. Dry the outside immediately afterward, then run the engine for a few minutes to help dry any parts that could not be easily dried with a cloth.

Once the equipment is clean, pay particular attention to any signs of fuel leakage. If a fuel leak is detected, tighten the parts causing the leak or replace them immediately. Failing to fix the leak is not only wasteful and inefficient but also potentially dangerous.

Regular Maintenance

In addition to daily checks, engines require a variety of maintenance on a less frequent basis. Throughout the year, engines need weekly, monthly, semiannual and annual maintenance to retain performance and maximize equipment life. Although the maintenance on all small engines follows a similar timeline, operators and mechanics should consult their operator’s manuals for maintenance requirements that are specific to their equipment.

A manual log may be used for tracking maintenance checks and services to ensure they are completed, or an optional hour-meter box can be purchased and attached to a machine to digitally register hours of use.

One item that not only needs to be addressed on a daily basis, but also bimonthly, is the engine oil. In addition to checking the level and quality of oil daily, change it every 100 hours to remove potentially harmful sludge. The only exception to changing the oil after 100 hours comes when the engine is first purchased. After using a new engine for 20 hours, change the oil to remove assembly lube and the metallic particles created during initial break-in.

The air filter also needs daily and bimonthly attention. Regardless of how dirty the filter is, clean it every 100 hours and change it monthly. If the air filter is not cleaned and changed, it will be prone to clogging, which causes a loss of power and shortens engine life by allowing dirt to enter internal components.

Most manufacturers recommend cleaning foam air filters with soapy water or a mixture of three parts kerosene and one part engine oil. After cleaning with soapy water, rinse the filter thoroughly, squeeze out excess water and blot dry with a paper towel or shop rag. Work a small amount of engine oil into the filter and blot away any excess before reinstalling it. If you’re unsure of the proper cleaning method, consult the owner’s manual. If the filter still appears dirty or clogged after cleaning, it should be replaced immediately. Another way to check for an abnormally dirty filter is to squeeze and release it; if it does not quickly return to its normal shape and size, replace it.

Clean a paper filter by removing it and tapping it on a hard surface to knock off any excess dirt. Do not use compressed air to clean the filter elements because it may cause tears in the paper. While manufacturers typically recommend replacing paper filters after about 50 hours of use, dusty environments will result in more frequent replacements. Checking the filter regularly ensures that a replacement is made when it is actually needed.

An operator also should inspect the spark plugs every 50 hours for damage, dirt and excessive carbon build-up. Dirty spark plugs can cause a decrease in power and poor starting performance. Clean spark plugs coated with a considerable amount of dirt or carbon buildup with a wire brush or spark plug cleaner. If the buildup seems excessive, it may be a sign of weak spark voltage, an incorrect carburetor adjustment, a lack of air cleaner maintenance or an incorrect fuel-air mixture.

Check the electrode gap on the spark plugs, as well, ensuring it still meets the manufacturer’s specifications, and adjust as needed. Replace any spark plugs with cracked porcelain immediately.

Additionally, it is important to clean and inspect the fuel strainer and fuel filter every month. Contaminated fuel that is not removed can lead to trouble with engine starts. Replacing the fuel line and carburetor is expensive, so it is essential to prevent unnecessary damage caused by contaminated fuel.

If there is sediment on the fuel strainer, shut off the fuel line valve before any maintenance or cleaning. Then, remove, empty and clean the sediment bowl and clean the filter screen. If sediment has made it into the tank, all the fuel will need to be removed. Clean the residue from the sediment reservoir, which is the lowest point in the tank. Use a clean rag to wipe sediment from the filter element and the sides of the tank before refilling the tank with clean fuel.

On an annual basis, inspect the engine for dirty, broken and misaligned parts. Such parts can cause a variety of engine problems, and thoroughly inspecting the engine gives the most comprehensive view of what needs to be cleaned and repaired. Furthermore, check the fuel hose each year, and replace it if there are cracks.

Following appropriate maintenance recommendations will ensure a long engine life and preserve the power and performance of the machine.

Although it may seem time-consuming to follow a strict maintenance schedule, most steps are fairly quick and easy to perform. And, in relation to the time and money required to fix or replace a faulty engine, a few minutes spent on maintenance is a small investment. It’s all about give and take – and grace under pressure only comes with an operator willing to spend time giving a little “TLC” to a hard-working machine.
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