There is an old saying, “Pay me now or pay me later”. This is especially true when laying up an engine for storage. Skipping steps at lay-up will guarantee expensive repairs at start-up.
General: Each manufacturer has recommendations for oil changes, filter changes, gear case lubrication, etc. Find the manufacturers’ recommendations for your engine and follow them. Change any oils (lubricants) before storage. Any moisture in the old lubricant can cause component corrosion and pitting on bearings, which should be avoided at all costs.
Petroleum based fuels are complex compounds with many additives during the refining process – more so now as fuels are reformulated to meet government mandates to lower pollution rates. Unfortunately these same agents that make for cleaner burn make the fuel less stabile. Diesel is now less than a 90-day fuel and gasoline is a 30-day fuel. After that the fuel deteriorates and loses a good portion of its efficacy. As fuel ages, asphatimes form, darken the fuel and eventually settle to form sludge at the bottom of the tank. A good stabilizer slows down this darkening and sludge formation. Old fuel often also contains water contamination.
K100-MD for diesel and K100-MG for gasoline contain enhanced stabilizers that hold the petroleum compounds together stabilizing the fuel to keep it fresh during the season, and contain solvents that dissolve asphatimes and put them back into the fuel. This maintains fuel power and protects equipment with increased lubricity. The cleaning action also dissolves deposits on injector tips to restore the spray pattern. Doubling the K100 treatment will keep fuel fresh during storage or if sitting for long periods of time.
Store with a Full Tank (Rather than an Empty One). When storing with a full tank there is less area to support condensation, and there are less volatile fumes that can be a source of combustion. These benefits outweigh any advantages to storing with an empty tank.
Prepping the Carburetor: Draining a carburetor dry may sound good in theory, but a carburetor cannot be completely drained. Some residual fuel will remain, which will turn to gums if left exposed to the air during storage. Gumming will occur even more quickly if there is any moisture in the fuel. Fuel treated with K100 will not form gums or varnish.
E-10 Gasoline: The new oxygenating agents in E-10 cause it to go bad faster than the old MTBE fuel, and accumulated condensation increases the risk of phase separation. A double-dose of K100-MG will keep E-10 fuel fresh for at least 6 months and prevent phase separation from occurring.
Bio-diesel Fuels: Bio-fuels contain high amounts of dissolved water. K100-MD is an especially good treatment for the newer bio-fuels because it eliminates residual moisture.
Preparing for Storage: Store with a full tank and treat the fuel with double the normal ratio of K100. Run the engine for a few minutes to make sure the treatment gets throughout the fuel system.
Removing from Storage: At the start of a new season the engine should be ready to fire up and go. If the storage period is longer than 6 months, change the fuel filter, drain 1/2 the tank and refill it with fresh fuel, add the normal amount of K100, mix as well as possible and start the engine. If it’s been a really long time, replacing all the fuel may be the easiest way to avoid starting problems, especially if using premix fuel in a 2-cycle engine. Remember that rubber components don’t like long term storage, so inspect hoses and seals carefully as they may need replacing.
Generator Storage: Generators typically sit for long periods of time, but when needed they need to work! Double-treat the fuel as described above, and replace it annually with new, treated fuel (drain the old fuel and use it in some other vehicle). Run the generator for at least 15 minutes to get it up to temperature and make sure it’s functioning properly, do an annual preventive maintenance check-up, and keep a new spark plug next to the generator.