Equipment Maintenance For Safety & Performance

By Bob Solesbee, The Lawn Mower Repair Man

Do not turn a 4-cycle engine upside down. When getting at the drain plug on a mower, tip the mower no more than 90 degrees and do so with the empty spark plug hole pointing up. You may want to place a piece of plastic (a sandwich wrap will work) under the fuel cap to prevent dribble. Don?EUR??,,????'???t forget to remove it when done. Photo courtesy Larry Shield

Designer Motor Fuel: Generally this is what is known as gas. Those of us who grew up with muscle cars once used real gasoline. What we buy at the pump today in no way resembles it, except it still runs engines?EUR??,,????'??+or tries to.

Remember, the manufacturer?EUR??,,????'???s recommendation is the minimum. I advise people to use 92 octane for all outdoor power equipment. Quality control at the refinery is usually tighter on the premium fuel, providing for fewer combustion deposits and more reliable performance. Using a major brand, high-octane fuel from a busy station will give you better all around performance with less chance of impurities.

Always walk the yard before using equipment. Look for and remove any debris your equipment wasn?EUR??,,????'???t designed to deal with. Rocks, dog bones and even coat hangers can cause damage to anything in its path. Photo courtesy Larry Shield

2-Cycle Oil

For many years folks have gotten away with using 4-cycle oil to mix with fuel for their 2-cycle engines powering blowers, trimmers and other equipment. Indeed, that was what many manufacturers recommended. Not anymore. The same was true regarding the use of 2-cycle boat oil in 2-cycle outdoor power equipment. Unless you want to use your power equipment as an anchor for your boat, don?EUR??,,????'???t do it.

Two-cycle outdoor power equipment today is a different animal. Twenty years ago a high revving 2-cycle would have turned 9,000 rpm, most much less. Today some are turning 16,000 RPM with the average around 10,000 to 14,000 rpm. Boat oil is made for relatively slow revving, cool-running water-cooled engines. Two-cycle outdoor power equipment engines are air-cooled and run much hotter. Boat 2-cycle or 4-cycle oil will cook a chain saw or line trimmer in a hurry. Today?EUR??,,????'???s 2-cycle air-cooled power equipment requires oil made for them. Use one of the oils made for one of the quality 2-cycle power equipment engine manufacturers.

Mixing Fuel/Oil Ratios for 2-Cycles

Fuel/oil ratios are very important for the life of an engine. Most 2-cycle engines today are advised to have the fuel/oil ratio mixed at either 40 to 1?EUR??,,????'??+or more likely 50 to 1. In other words, 50 parts of fuel to one part oil. One gallon of fuel is 128 fluid oz. Divide that by 50 and you come up with 2.56 fluid oz. of oil needed to mix with that one gallon of fuel. Just 2.5 oz. of oil?EUR??,,????'??+that?EUR??,,????'???s not much but it?EUR??,,????'???s critical to get the measurement as accurate as possible. Never try to estimate fuel and oil as you pour them into the equipment?EUR??,,????'???s fuel tank. You?EUR??,,????'???re not likely to get it right.

Today?EUR??,,????'???s equipment has little if any outward adjustability to compensate for fuel or air flow variables. This is so the engines can meet the new emission laws and not need to be recertified every year. If the carburetor had the same easily-adjustable and tamperable jet screws of the past the feds wouldn?EUR??,,????'???t allow the engines to be sold.

The careful maintenance of a small motor?EUR??,,????'???s air filter and carburetor are the most important keys to an engine?EUR??,,????'???s longevity. The air filter (top) for this reel mower sits on top of the carburetor (bottom), which regulates the motor?EUR??,,????'???s fuel and air mixture. Photo courtesy Erik Skindrud

Air filters come in two types, paper cartridge and oiled foam (seen here). With a consistency like a foam pad or sponge, the latter type can be washed in warm, soapy water, re-oiled with 30w motor oil and reinstalled in its steel cover (seen below here). Photo courtesy Erik Skindrud

Oil for 4-Cycle Engines

Choosing oil for a 4-cycle gasoline lawnmower engine is fairly straightforward. If you still have your owner?EUR??,,????'???s manual, check it for any variables. Generally 4-cycles are good to go with a quality automotive 30w oil. For cold climates (when the outside temperatures drop below freezing during the time of use) change the oil to a 5w-30 or 10w-30. When it warms back up change back to straight 30w. A single-viscosity oil is best whenever possible for power equipment due to being air cooled and the resulting higher operating temperatures. In a pinch, the multi-viscosity oils are OK when it?EUR??,,????'???s hot, but change these blends out as soon as possible before the oil breaks down under the hot running conditions. Sticking with a major brand is the safest choice for quality.

The Bobcat S150 has a 46-h.p. diesel engine that is rated to lift and carry 1,500 lbs. The same principals that apply to lawnmower engines, such as the value of clean fuel, carburetors and air filters, apply to a larger machine like this skid-steer. Photo courtesy www.bobcat.com

Always, when operating power equipment, wear safety glasses, non-open and slip-resistant shoes and long pants. Hearing protection for chain saws and blowers are also a good idea. Hearing protection blocks out dangerous noises but allows you to still hear sounds.

Oil Changes

New equipment should have its first oil change inside the first five hours of running time. If you only run your equipment a half hour per week, change the oil after a month on a new unit. New engines have a lot of initial break-in contaminants and need to be replaced early. No special break-in oil is needed or advised. Use the regular good quality oil you plan to continue to use. After that, change the oil every 25 hours of running time or once a year. If your equipment is used in dusty conditions change the oil more often. Engines with an oil filter usually need less frequent oil changes in terms of hours used. Check your manual or ask your dealer. If you use your engine in sub-freezing conditions in the winter you need to replace the 30-weight oil (standard for normal conditions) with a 5W 30 or 10W 30. Remember to return to the straight 30-weight when it warms up.

This compact Kawasaki carburetor is made to fit certain models of backpack blower. The failure of a piece of equipment to start is often due to carburetor problems. Mower carbs are often rebuilt but it usually makes sense to replace a blower part. Photo courtesy Larry Shield

Spark Plugs

Spark plugs are cheap. Replace them when you change the oil. If you have a 2-cycle where oil changes aren?EUR??,,????'???t needed, replace the plug when you clean or replace the air filter. Plug gap and type are important. Check your owner?EUR??,,????'???s manual for correct type and gap. All new engines since 1995 have been required to meet emission regulations and tampering with emission-control hardware is illegal. Spark plugs are part of the emission package. Every new engine regardless of the equipment it powers, comes with an owner?EUR??,,????'???s manual which states emission and maintenance requirements and the spark plug type and gap specification. It?EUR??,,????'???s not likely that the consumer will be cited and charged with emission tampering, but the law does exist.

This paper cartridge air filter is similar to the type used in trucks and automobiles. This cartridge fits a backpack blower?EUR??,,????'??+and will need to be changed frequently due to the machine?EUR??,,????'???s abundant exposure to dirt and dust. Photo courtesy Erik Skindrud

Air Filters

Stuff a pillow in your face and see how easy it is to breathe! I see a lot of equipment that has excess combustion chamber carbon build up and prematurely fouled spark plugs. That happens because the user hasn?EUR??,,????'???t serviced the air filter. What they?EUR??,,????'???ve done is stick a pillow in front of the carburetor and expected the engine to perform flawlessly. Mowers, tillers and other lawn and garden equipment live right next to the ground and it?EUR??,,????'???s an extremely dirty environment. Check the air filter?EUR??,,????'???s condition every couple of tanks of gas until you get a good idea how long you can go between air filter servicing. If you?EUR??,,????'???re mowing a lush green lawn the filter will probably be good until it?EUR??,,????'???s time to change the oil. On the other hand, a rototiller may need its air filter serviced in less than an hour.

Filters come in two basic types. Paper cartridge (much like you may be familiar with in your car) and oiled foam. Some paper cartridges have a foam pre-filter. These usually are not oiled because over oiling can cause oil transfer to the paper filter and destroy it. When a paper filter gets dirty it gets replaced. Foam filters, if not deteriorated, can be washed in hot soapy water, re-oiled with 30 wt. motor oil and re-installed.

Many mowers and other pieces of equipment include engines made by other manufacturers. This Toro mower utilizes a Kawasaki engine, for example. The engine manufacturer is an important bit of information to pass on when consulting a repair expert. Photo courtesy Erik Skindrud

Play it Safe

For the better part of 20 years of repairing outdoor power equipment I?EUR??,,????'???ve managed to avoid any serious injuries. That?EUR??,,????'???s something I plan to continue. Injuries from power equipment aren?EUR??,,????'???t a joking matter.

Re-fuel outdoors, with the engine cool, away from any sparks, flame or heat source.

After an extended storage, the fuel should be drained and disposed in a proper manner before refilling the tank with fresh fuel. The old gas would be as difficult to start as before, but having had stabilizer in it will prevent the coating and shellacking from happening. Photo courtesy Erik Skindrud