Gas and oil: The lifeblood of your power equipment
The quality of the gas and oil you use significantly impacts the longevity of your power equipment. Thus, use of cheap oil or old gasoline is detrimental to your engine-potentially causing permanent damage. The difference between good oil and cheap oil is usually less than $1 per quart, yet it can save you hundreds of dollars in long-term maintenance.
Recommended fluids Recommendations for gas and oil have changed over the years. Manufacturers have developed new gas additives and made major changes in modern motor oils. If you want your equipment to last as long as possible and to perform like new-even if the engine is more than eight years old-pay attention to what you feed it. When it comes to gas and oil, you should follow the manufacturer's recommendation in all circumstances. Using a non-recommended oil, gasoline or additive can void the manufacturer's warranty and could your equipment.
Gasoline Gasoline contains a great amount of energy. It should ignite readily, burn cleanly, resist detonation (violent burning), vaporize easily-without being subject to vapor lock (when fuel vaporizes in fuel lines and impedes the flow of fuel to the carburetor) and be free of dirt, water and abrasives.
Gasoline is assigned an octane number corresponding to its ability to resist detonation. You can find this octane number on the front of the gasoline pump. Premium-grade gasoline burns slower than regular gasoline. It has a high octane number and is used in engines with high compression. Regular-grade gasoline has a lower octane number and burns relatively fast. Generally, regular gasoline is used in small one- and two-cylinder gasoline engines with low compression.
Your choices for gasoline are regular or premium. Most engine manufacturers recommend gasoline with an octane rating of 85 to 89 (regular). For some equipment, manufacturers recommend the use of premium grade gasoline (90 or higher)-usually on equipment with a catalytic converter. Most manufacturers don't recommend the use of gasohol, but if you must use it, make sure the ethyl-alcohol content does not exceed 10 to 11 percent. Gasohol draws moisture from the air, permitting peroxides and acids to form in the fuel. These chemicals can harm-and possibly destroy-the engine.
Reformulated gasoline (RFG) Some of the country's largest cities are presently using reformulated gasoline (RFG): Los Angeles, San Diego, Chicago, Houston, Milwaukee, Baltimore, Philadelphia, Hartford and New York City. These are cities where the highest levels of ozone, air pollution and smog exist. In addition, several other areas with ozone levels exceeding the public health standard have voluntarily chosen to use RFG.
RFG and conventional gasoline differ only in the proportion of ingredients they use, thereby reducing the use of ingredients that contribute to air pollution. RFG will not evaporate as easily as conventional gasoline. RFG contains "chemical oxygen" (oxygenates). Gasoline is made up of different hydrocarbon compounds including aromatics, olefins and benzene-all of which contribute to ozone and air pollution. The levels at which these components are present in RFG are lower, resulting in fewer harmful emissions.
The basic facts about RFG are: *It requires 1 to 3 percent more gasoline to run your equipment *The performance of your equipment will decrease about 5 percent *You can mix RFG and non-RFG gasoline.
You shouldn't run older equipment (more than 5 years old) on RFG. Because of the alcohol content, the fuel lines and hoses might be more prone to damage from alcohol-oxygenated fuels. Hoses that are susceptible to alcohol damage can become brittle or soft and, over time, deteriorate. (Robert: this sounds like an effect of gasohol. Does RFG & gasohol cause this damage?)
For storage purposes, it's best to completely drain the fuel system-of all machines, no matter the fuel-type-during off-season.
If you are environmentally conscious, it may comfort you to know that you will be helping the environment by using RFG gasoline. Studies have shown that pollution output is 15 to 17 percent lower.
Based on the previous facts, if you have a choice, you probably should not use this type of fuel in your power equipment. If you must use RFG because of your location, make sure your gasoline is always fresh, because the RFG formula changes from winter to summer.
Gasoline additives Every manufacturer recommends a specific way to store its equipment to prevent carburetor varnishing and partial plugging of carburetor jets. Either of these conditions can cause the engine to run lean and can result in piston seizure and engine failure. Manufacturers commonly suggest two methods for storing their equipment when not in use: *Run the engine until it totally runs out of gas. *Fill the tank full and add a gas additive.
This second method requires that you to run the engine for 5 minutes to make sure the gas additive and gasoline get mixed together and works through the carburetor.
Most manufactures are now recommending fuel stabilizers that keep fuel fresh for off-season storage. Un-stabilized fuel will stay fresh for only 2 to 3 months and should not be used after that time. Stabilized fuel can stay fresh throughout the off-season.
Four-cycle oil Walking past the oil displays at the store can confuse even the most trained mechanic. You'll find a variety of brands, weights, synthetic blends and full synthetics from which to choose. Most manufacturers recommend choosing oil according to the expected air-temperature range during the period between oil changes (see tables, page XX). The synthetics offer the broadest range of protection for gasoline engines. Other advantages for using synthetic oil include: *Provide excellent engine protection during high-temperature operation. * Extend engine life by reducing wear. *Allow faster cold starts. *Help prevent oil breakdown and keep engines cleaner. * Are compatible with conventional oils.
Keep in mind, however, that many manufacturers don't recommend synthetics for 2-stroke engines.
My personal recommendation for oil use breaks down into two parts. First, during the warranty period, use the manufacturer's recommended oil. Don't do anything that could cause the manufacturer to void your warranty. Second, after the warranty period, choose a good, synthetic oil. I have been running a 5w50 synthetic in my garden tractor for the last 9 years. Granted, the full-synthetic oils are more expensive, but when you consider longer engine life, easier starting, better fuel economy and fewer oil changes, you're actually saving money using a synthetic.
Two-cycle oil Two-cycle engines receive lubrication only from the oil mixed with the gasoline. Because of this, it is important that you use the correct quantity and quality of oil with the specific amount of gasoline. Always follow the manufacturer's specifications as to type and quantity of oil to use. Two-cycle oil is not the same as standard-engine motor oil as discussed above. Do not interchange them.
If you don't use enough oil, the engine will overheat. Overheating, in turn, causes expansion of parts and possible scoring of machined surfaces. Eventually, the pistons may seize (bind, then stick) in the cylinders. Excessive oil, however, will cause incomplete combustion and rapid buildup of carbon-fouling the spark plugs and adding weight to the pistons.
The proper way to mix gasoline and oil is to pour some (about half) of the gasoline into a clean container specifically made for gasoline. Add the oil to the gasoline and agitate (shake) this partial mixture. Add the rest of the gasoline and agitate thoroughly again. Once you thoroughly mix the gasoline and oil, the oil will remain in solution indefinitely.
Clearly mark this container as to its contents, such as "Oil/Gas 1:32" meaning it contains an oil- and gas-mix with a ratio of 1 to 32. (The table on page XX provides recommendations on mixing gas and oil.)
Times, they are a changin' Modern motor oil has had drastic changes in its content compared to years past.
*Detergent dispersants now remove dirt and keep it from collecting as sludge.
*Viscosity improvers keep the thickness of the oil constant.
*Extreme-pressure agents increase film strength and insure constant coverage of bearing surfaces.
*Pour-point depressants give the oil faster coverage ability.
*Defoamants ensure the oil does not foam.
*Anti-oxidants prevent overheated oil from thickening and forming tar and varnish.
* Friction modifiers help cut internal drag.
When purchasing motor oil, stick to the name brands. Stay away from oils that have generic or no-brand names. A difference can exist in the quantity and quality of ingredients.
Bio-degradable oils Many manufacturers recommend the use of chain oil-which is biodegradable-to protect the environment. Biodegradable oils are made of special vegetable oils and are 100-percent biodegradable. Most oil of this type is stable only for a limited period. Most manufacturers recommend that you use biodegradable oil within 2 years from the date of manufacture (printed on the container). Do not purchase biodegradable oil that is old or of unknown origin.
Storage To properly store power equipment that you won't use for more than 45 days, most manufacturers recommend this checklist: *Fuel maintenance (see subhead "Gasoline additives", above) *Change engine oil when the engine is warm *Repair any worn or damaged parts; Install new parts if necessary *Sharpen blade, chain or other applicable parts *Service the air filter *Lubricate all grease points *Wash or wipe down the equipment *Apply paint to areas that need it to prevent rust *Remove the battery and clean it; check electrolyte level, charge and store in a cool place *Close fuel-shut-off valve *Check belts.
Safety It is not appropriate to talk about gas and oil without mentioning safety. When you work around fuel, use the following guidelines to help ensure the highest safety standards: *Do not smoke or work near heaters or other fire hazards. *Fill, mix or agitate gasoline only outside or in a well-ventilated room. *Do not inhale vapors; avoid any fuel contact with your skin. *Use only approved-fuel containers. *Store flammable fluids away from fire hazards. Do not incinerate or puncture pressurized containers. *Make sure all power equipment is clean of grease and debris. *Do not store oily rags-they can ignite and burn spontaneously. *Keep a first-aid kit and fire extinguisher handy-usually best mounted near an exit door. *Keep emergency numbers for doctors, ambulance, hospital and fire department near your telephone. *Wear close-fitting clothing and safety equipment appropriate to the job.
Robert Sokol is associate editor of Intertec Publishing Corp.'s ABOS Outdoor Power Equipment Book in the company's Technical Manuals Division. He is an ASE triple-certified master mechanic and a mechanical inspector for the Overland Park, (Ks.) Police Department. He is also a consumer automotive advocate for the national television show "Fight Back with David Horowitz."
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