Equipment Maintenance

When you think about storing equipment for the winter, what is the first thing that comes to mind? A simple wash and wax? Or do you really get it ready for a period of long storage? Storage of equipment should not be centered around a particular season. Let's face it, there are sections of our country that see no snow or what we in the North perceive to be “winter.” With that in mind preparing equipment for storage is simply seasonal.

For the most part, people follow their owner's manuals for recommendations on how and when to perform maintenance on their equipment without understanding fully what it is they are trying to do. Although regular maintenance does help the overall performance of your equipment and helps to reduce valuable down time, seasonal maintenance has many other benefits. Any time a machine will be left idle for an extended period of time (5 to 10 weeks), it is a good idea to implement some or all of the following maintenance practices.


Choose a location for storage that is out of direct sunlight. This one aspect could save you many hours of down time and costly repairs. A constant cycle of warming and cooling on metal parts will cause condensation to form on them. If this occurs for a period of time, the water can accumulate. When this happens to a gas tank, carburetor or engine blocks, it can be damaging. These areas are what are known as semi-sealed. If you live in a climate where it freezes, ice can form in these areas and break parts.

Just because you live in a warm climate, water can still be a problem for you if it gets in the gas or fuel system. This can cause the engine to misfire or stop running altogether. When water is left in contact with aluminum parts, like those found in a carburetor, it can cause them to oxidize, indicated by a white, powdery residue. If this is left in the fuel for long, it could dissolve and plug the many small passages found in all fuel systems. This can cause severe pitting, resulting in the need to replace the carburetor.

If this problem were to be present in the crankcase with unpainted parts, the same pitting and rusting can occur. This could require remachining or replacing costly internal parts.

Some plastics and rubber also are affected by prolonged exposure to sunlight. Some of these items include belts, hoses and manifolds. The best place to store these items is in a cool dark space where the temperature should remain fairly constant to limit the amount of condensation forming on parts.


Temperature has an effect on how fast fuel will evaporate; the warmer it is, the faster it will evaporate. Large volumes of fuel will evaporate slower than small ones, which is why you should try to keep fuel tanks full and the small fuel bowls on the carburetors drained. One other reason for doing this is to keep the unpainted surfaces inside a metal fuel tank from rusting. The last reason to keep fuel tanks full is that the air space above the fuel will change temperatures much faster than the liquid fuel will. This will reduce the amount of condensation from forming in the fuel tanks.

Follow the same guidelines even if you have plastic fuel tanks. They may not rust, but you will still have a cavity for condensation to form. Therefore, if the tank is small enough, drain it since there are no metal parts to rust, or keep it full if it's too large to drain.

In a situation with two-stroke engines that use diaphragm-type carburetors, you can't drain the carburetor because the diaphragms may harden and crack. Use a chemical treatment to keep the fuel fresh and to prevent varnish from forming. Chemical treatments can be used in all types of motors and may keep the fuel fresh but will not keep the unpainted parts from rusting or the condensation from forming.


Proper storage will leave you with fewer repairs in the following season when you return a piece of equipment to service. However, there are some common breaks that occur, especially when equipment is neglected.

Four-stroke engines usually encounter a varnish build-up problem within the fuel system. This is sometimes covered by dirt, too. The source of the dirt may also be from the varnish; this happens when it becomes hard and rattles loose. If the equipment has not been idle for that long, the varnish still may become gummy and soft. The long-term storage problems usually result in hard crystal. These particles quite often become dislodged and remain in the fuel system. When the engine is running, the fuel flow draws them in to the small passage that feed fuel to the motor.

The best way to remove the gummy deposits formed after short-term storage is with some sort of spray-type carburetor cleaner. These spray cans will force cleaner down the small passages to flush out the material. Another method to get these small passages clean is to use compressed air. These cleaners are available at most local automotive supply houses. If you don't take care of these problems early on, you may find yourself faced with a more difficult method for removal or even have to replace parts that are uncleanable.

This next method of cleaning is one of those harder ways to clean parts: dip-type solvent cleaners. These are very caustic and need to be handled with extreme care. Follow the instructions on the label for disposal, handling and length of time for parts exposure. Many of these cleaners can dissolve rubber parts if you expose them too long, so you'll need to completely disassemble the entire carburetor before placing parts in the cleaner. This will also ensure that the solvent reaches all the parts of the carburetor. If the carburetor still is not clean, you will need to repeat this process rather than increasing the time that the parts are exposed to the solvent. You may need to soak the carburetor as many as three times before they are completely clean.

It's vital to follow the instructed time for exposure, because these solvents are so caustic that they could destroy even some of the metal parts. This is true especially if the aluminum is pitted from water being left in the carburetor for a long time. When left in the solvent, metered passages will get larger as the metal is removed, leaving the carburetor useless.

If you have a build-up of debris or varnish in the small passages and air bleed holes, use a small parts-tag wire to remove the material. Be careful to not get too aggressive with this because you will enlarge these holes and cause the metering to be changed and you'll have to replace parts. Try to avoid using of torch tip cleaners here because they have ribs that act like file teeth and could remove too much metal unless you are skilled enough and develop a sense of feel for how much you are removing.

When cleaning two-stroke carburetors, use many of the same methods as above. The main difference is that you'll have to deal with more diaphragms and gaskets before dipping the parts. The fortunate thing with this type of fuel is that with the mixture of gas and oil, the gas evaporates and leaves the oils behind. This usually will result in the varnish remaining in the gummy stage longer, although it is possible to get them to cake-up and harden. Also, with an increase of the number of engines that are oil injected, the oil is not in the fuel until the point intake at the engine. This means that fuel bowls are full of straight gas, not a mix of gas and oil.


Fuel tanks, for the most part, are easier to clean because they start out with fewer moving parts. Many of the same solvents will clean them but you first need to find out what you are up against. The easiest way to do this is to drain the tank and inspect the inside.

The most common problem is rusty metal. For this problem, put a package of BB's and some parts-washer solvent in the tank and aggressively shake them around to knock the rust scale loose from the tank. After the BB's have done their job, pour the contents through a paint strainer or shop cloth to collect all the BB's for later use. Then, with repeated flushing of the tank with clean parts-washer solvent, you should be able to get most of the rust out.

If you noticed the problem soon enough, this may be the end of your repair and you can return the tank to service. But if the tank still has some rust that won't knock loose or if there is deep pitting and pinhole leaks, you might have to use a tank sealer. Use sealer made specifically for gas tanks, anything else will dissolve in the gas and cause problems farther down the road in the carburetor.

Even if you have plastic tanks, you are not free from similar problems. While the tank can't rust, the fuel can still evaporate and leave behind gummy or even dried residue that you'll need to remove. The BB method will work for plastic tanks as well. With this in mind, if you find yourself in need of a replacement tank, use a plastic one if at all possible.

The last thing in dealing with fuel tanks is the use of chemical treatments. One in particular is dry gas. Remember, this product is packaged for convenient use in automobiles that have a 15- or 20-gallon tank. Keep this in mind when adding it to your equipment's 2- to 5-gallon tank and adjust the ratio of your mix accordingly.


If you have an oil-injection system that is in need of repairs, it is most likely caused from dirt getting in the system. Oil is very stable for a long time and won't usually gum up like gas. This makes the repair easier. You completely disassemble the system to remove the all the dirt and then reassemble it; use good quality oil (name brands), not a generic hardware store brand, or you could use the same brand as the equipment manufacturer. Take your time when buying this equipment and look at the big picture to make sure all of your two-stroke equipment is the same and you can stock one oil instead of several different mix ratios and brands. Confusion could lead to problems down the road.

Fuel-injection systems, on the other hand, have some problems dealing with long-term storage. There is not a good way to drain a gasoline fuel injector, so the small amounts of fuel left in them are subject to gumming up. Sometimes chemical treatments will clean these units out; if not, they have to be replaced. These chemical cleaners rely on fuel passing through them to flush out dirt and gum. This is another chance for material that has been dislodged somewhere else in the system to get caught in the injectors. The metered openings in these injectors are extremely small and can plug easily with lint from a shop towel.

If you have to replace these injectors, make sure that all the engine parts are cooled down before attempting to break high-pressure fuel lines open. Also make sure that when you replace the injector, you also change the filters and lines and clean them, or at least flush them out before installing a new unit (this includes the fuel tank). Many new injectors have failed after service because a filter or line has not been cleared of debris. Also take special note of the type of filter you use — injection systems run either high-pressure or high-volume, and a conventional filter for gravity feed system will tear if it is subjected to these extreme pressures.

It's often assumed that contaminants come from the fuel supplier, but sometimes we are at fault. Dirt can get into fuel systems when we leave tops off gas cans and leave them out in the weather (rain and snow). With this in mind, keep fuel filters changed, keep gas caps in place and be aware of where your fuel can is stored. Use your fuel cans for the same fuel all the time. Don't switch back and forth from gas to diesel or gas to two-stroke pre-mix fuel. And keep your gas cans clearly marked so you and your employees know what is in them.

Reformulated gas is a blend of fuel that uses special oxygenates that have a tendency to attract moisture, largely due to the fact that they use a blend of alcohol. Alcohol will draw moisture out of the air, so it's important to be more careful on how you store your supply fuel and equipment.


Until now, we have been talking mostly about engines and fuel systems. However, there is more and more liquid-cooled equipment to choose from in today's market, so remember to take off the cooling system when it comes time to store equipment for the off-season. Make sure that your equipment has proper freeze protection for your area; this usually requires a 50/50 mix of antifreeze and water. Almost all of your compact equipment has an aluminum radiator or at least aluminum head. For this reason, make sure your antifreeze is suitable for aluminum.

The water you use also is very important; you need all the thermal capacity you can get from little radiators. For this reason, you should use only distilled water in the coolant mix. This will reduce the mineral buildup in the cooling system more than if you used tap water that, in most cases, could come from a well. Change the coolant on the manufacturer's recommended schedule to reduce the silt and sediment that seems to get into the expansion tanks through the breather caps as the equipment is used.

If you buy antifreeze in bulk, make sure it has all the protection your equipment needs. What might be good for a passenger car might not be good for your compact tractor with a roto-tiller on it in 100-degree heat. Remember the effect that sunlight has on equipment. It is important to mention that the belts and hoses also are subject to these elements. Check them before you put the equipment away for the season. This is the first step to making sure the repair happens before the equipment is returned to service. Speaking of service, there are testing labs out there that will analyze your coolant and tell you if there are parts that are getting worn out by the amount of metal that is dissolved in it. The same type of testing is available for oil as well; this will show how much wear the engine is experiencing.


You should assign a maintenance schedule to the entire piece of equipment for all seasons. Most equipment has grease fittings and gear boxes that require special service. If this is forgotten until the machine fails it would result in a very costly repair, as well as a lot of down time. If you are a commercial user and have employees that use this equipment, it is almost impossible to keep track of the last service without a record of maintenance on each piece of equipment.

With all this in mind, the next piece of equipment you purchase should have some key features, such as a plastic fuel tank, a quality fuel system with shut-offs and drains and a quality cooling system with screens to protect the radiator from chaff and dirt. All the best features still can't outperform good quality maintenance.

Larry Van Deusen is a professor in the Department of Agricultural Engineering Technology at State University of New York, Cobleskill (Cobleskill, N.Y.).


What causes varnish buildup in the fuel system?

  • Fuel left in small volumes for too long.

  • No chemical additives used for storage of equipment.

How do you clean varnish buildup?

  • Use BB's to rattle debris loose so it can be flushed out (gas tanks).

  • Spray areas with carburetor cleaner (fuel bowls).

  • Chemical dip treatments.

  • Fuel additives to help dissolve materials in the system (fuel injection).

How can you prevent storage problems with fuel systems?

  • Drain small-volume areas (like carburetors).

  • Fill larger-volume areas (like fuel tanks).

  • Don't store equipment in direct sun light (temperature changes).

What areas of equipment need to be considered for storage?

  • Cooling system
  • Gear boxes
  • Axles and differentials
  • Fuel system
  • Hydraulic system
  • Batteries

In all cases, you should follow the owner's manual for proper maintenance schedules and procedures.

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