Storage of gas powered equipment.
2-CYCLE FUEL RECOMMENDATIONS
· Use fresh "SUPER" grade gasoline mixed with
premium 2-cycle oil, not outboard motor oil.
· Fresh means less than one month old.
· Do not store fuel for more than one month. Mix small
batches at a time.
· Do not keep fuel in machine for more than one month.
· Follow machine makers mix ratio of gas/oil, not oil companies
ratio.
4-CYCLE FUEL RECOMMENDATIONS
· Use fresh "regular"* grade gasoline.
· Fresh means less than one month old.
· Do not keep fuel in machine for more than one month.
· Do not store fuel for more than one month.
*consult owners manual for verification
THE TECHNICAL STUFF
2-cycle
We have found spark plug fouling to occur more frequently on small
2-cycle engines than on 4-cycle. We have also seen the rate increase
with older gas. It has also been proven that "regular"
grade gas can cause seizure of the piston & cylinder, even
with the correct gas/oil ratio, due to the higher energy content
of regular gas, excess heat can burn off the oil film, causing
catastrophic failure, therefore super grade gas is a must.
These problems have occurred since the introduction of unleaded gas, and the use of detergents in the gas to clean the injectors of fuel injected automobiles. It is our belief that the detergents wash the inside of the engine, causing a conductive coating to form on the porcelain insulator of the spark plug, and therefore cause the plug to not fire, or mis-fire under compression. Old gas seems to accelerate this problem. Until better spark plugs for this condition appear on the market, the best thing to do is use fresh super unleaded gas, and keep a spare spark plug in case. Since it takes greater voltage to fire the plug under compression, than in free air, simply removing the plug and cranking over the engine and looking for spark does not prove the plug is good, only replacement with a new plug will do this.
Outboard motor oil is made for water-cooled engines, not air cooled. Chain saws as an example run very hot due to their normally dirty cooling fins, and experience a lot of "thermal shocking" due to the normal use of rapid operation from idle to full throttle, full load, to idle. Therefore do not use outboard motor oil, but stick with high quality 2-cycle oil. Any name brand for a chain saw is good. There are not yet any standards for air-cooled 2-cycle oils, only proposed standards.
4-cycle
We suggest the use of regular grade gas rather than super. Super
gas burns slower, for high compression automobile engines, where
regular pre-ignites due to the higher compression ratios, in a
similar manner to a diesel, where the compression alone is sufficient
to ignite the fuel. Therefore super may still be burning as it
leaves the exhaust valve (due to its slower burn rate), and get
"squished" by the exhaust valve, this intensifies the
heat of the flame (similar to a blast furnace), and causes the
"burning" of the exhaust valve. However you should consult
your owners manual to be certain of the fuel requirement.
Engines operated in the winter benefit from the use of synthetic engine oils. Starting is easier, and initial lubrication is immediate. It is also easier on the starter mechanism, and your arm. Summer only applications benefit from SAE 30 oil rather than multi-grade oil.
General
Remember, most engines to-day use plastic fuel tanks, and most
consumers use plastic fuel cans to store fuel. These containers
allow oxygen to permeate into the container and oxidize the fuel,
and since both the container and fuel are made from oil, there
is also a compatibility that allows for the volatile parts of
the fuel to migrate through the wall of the fuel tank, leaving
a less than perfect fuel for operation. Therefore, fresh fuel
is mandatory for less problems.
The new equipment coming onto the market as of 1998 is generally EPA (environmental protection association) or CARB (California air Resources Board) approved due to American legislation. These new engines have no high speed adjustable jet, and limited range low speed jets. They are therefore not tolerant of variations in the volatility of fuel, or of any varnish build up in the carburetor from stagnant fuel in the carburetor. Therefore, fresh fuel and proper storage is even more important with these new environmentally friendly engines.
4-CYCLE OIL RECOMMENDATIONS: For small air cooled engines.
Summer: We prefer SAE (society of automobile engineers) #30 HD (heavy duty) detergent based motor oil. 10W30 is an acceptable substitute, but generally will result in greater oil consumption.
Winter: We generally use a synthetic 10W30, or we suggest 10W as an alternative. Some manufacturers suggest 5W30 as well.
The "W" in the grade label means "winter", in other words this W graded oil is made for winter use.
Never use non-detergent oil in modern air cooled engines, as it might break down with the heat causing major engine damage.
2-CYCLE OIL RECOMMENDATIONS: For small air cooled engines.
The best choice is the equipment manufacturers own brand name of oil. In other words Homelite® oil works best in Homelite® products. Although we have found that mixing of brands is OK, we like to stick with brands of oil that are sold under equipment manufacturers names, not house brands (the equipment manufacturer has to warranty to machine, not the oil company).
The proper mix ratio is that proposed by the original equipment manufacturer, not the oil company.
Never use outboard oil in air cooled equipment. Outboard oil is made for water cooled engines that operate at much lower temperatures than air cooled.
GAS/OIL MIX - HOW TO DO IT:
The mix ratio required by the equipment manufacturer is usually given as a ratio of gas to oil. In other words, a 32/1 mix ratio means 32 parts gas to one part oil. In order to calculate this mix, we must use a common denominator. Therefore, since the oil is normally purchased in milliliter (ml) sizes, you must work with ml's for the gas. If we bought a 250 ml bottle of oil, we multiply that number by 32 to come up with 250x32=8,000. We would therefore need to mix 8000 ml's of gas with 250 ml's of oil to get the 32/1 ratio required. Since gas is sold by the liter, simply divide 8000 by 1000 to convert ml's to liters, and we need 8 liters of gas.
If we work this same formula backwards, in that we have a given amount of gas, let's say 4 liters, then we have 4000 ml's of gas and need to divide by 32 to come up with 4000/32=125. Therefore we need to add 125 ml's of oil to 4 liters of gas to get the required 32/1 ratio.
To sum it all up, if you know the
quantity of oil, then multiply by the larger ratio number given
(eg. 32/1, multiply by 32).
If you know the quantity
of gas, then divide by the larger ratio number given (eg. 32/1,
divide by 32).
Always work with the same unit of
measure, you cannot multiply or divide liters into milliliters
or vice versa, so normally work with milliliters and finally convert
the gas to liters by dividing by 1000.
If you find the above confusing and need more clarification, phone us (450-458-5251) or e-mail us for more information. The proper mixing is important to the life of your equipment.
STORAGE OF GAS POWERED EQUIPMENT:
With changes of gas formulations and the advent of environmentally friendlier engines, proper off-season storage is becoming more important in order reduce downtime and cost. The following is designed to help you from the engine perspective only, not the entire machine.
The best method of storage is to use a fuel stabilizer available from us or at most small engine equipment dealers. Follow the manufacturers mix ratio for your fuel, the run the engine for several minutes to make sure the stabilized fuel has gone throughout the engine. If there is a fuel shut-off valve, close it and let the engine come to a stop. If not, shut off the ignition. Top up the fuel fully to eliminate air space. We like to put a plastic bag under the fuel cap so that the fuel tank vent is also closed to prevent both evaporation and oxygen infiltration. Remove the spark plug(s), and pour a little oil in the cylinder(s). Then crank the engine over slowly to disperse the oil. Re-install the spark plug. If the engine is a single cylinder four stroke, pull the starter cord slowly till you feel compression (the hard part of the pull), now your engine is ready to be stored. When you go to use it again, don't forget the plastic bag under the fuel cap.
The second method of storage is to run the engine out of fuel. Then remove the spark plug(s), and pour a little oil in the cylinder. Then crank it over slowly to disperse the oil. Re-install the spark plug. If the engine is a single cylinder four stroke, pull the starter cord slowly till you feel compression (the hard part of the pull) and leave the engine alone.
In our shop, we use stabilizer and have had great success, in fact it is always in our shop fuel.