A prolonged period without use is not good for any piece of machinery. Engines should be started and cycled every week. Load the engine every two weeks to the extent that it would be in normal operation. This is particularly important for standby power. Prolonged idling or running under a reduced load may cause oil consumption and carboning in the combustion chamber and result in poor performance and a loss of power. If long periods of idling are necessary, run the engine under load every four hours to clear carbon from the combustion chambers.
If an engine is going to be put in storage see your Caterpillar dealer for storage instructions.