Engine Preservation

in Light-Sport Aircraft Engines

If the engine is not going to be used for an extended period of time, certain measures must be taken to protect engine against heat, direct sun light, corrosion, and formation of residues. In particular, the water bonded by the alcohol in the fuel causes increased corrosion problems during storage. After each flight, activate choke for a moment before stopping engine. Close all engine openings like exhaust pipe, venting tube, and air filter to prevent entry of contamination and humidity.

For engine storage of one to four weeks, proceed with preservation prior to engine stop or on the engine at operating temperature. Let the engine run at increased idle speed. Shut the engine down and secure against inadvertent engine start. Remove air filters and inject approximately 3 cubic cm of preservation oil or equivalent oil into the air intake of each carburetor. Restart the engine and run at increased idle speed for 10–15 seconds. Shut engine down and secure against inadvertent engine start. Close all engine openings, such as exhaust pipe, venting tube, and air filter, to prevent entry of contamination and humidity.


For engine storage of engine for longer than four weeks and up to one year, proceed with preservation prior to engine stop and on the engine at operating temperature. Let the engine run at increased idle speed. Remove air filters and inject approximately 6 cubic cm of preservative oil or equivalent oil into the air intake of each carburetor. Stop the engine. Remove spark plugs and inject approximately 6 cubic cm preservation oil or equivalent oil into each cylinder and slowly turn crankshaft 2 to 3 turns by hand to lubricate top end parts. Replace and re-torque the spark plugs. Drain gasoline from float chambers, fuel tank, and fuel lines. Drain coolant on liquid cooled engines to prevent any damage by freezing. Lubricate all carburetor linkages using the proper lubricates. Close all openings of the engine, such as exhaust pipe openings, venting tube, and air intake, to prevent entry of any foreign material and humidity. Protect all external steel parts by spraying with engine oil.