# Overhaul

To achieve the best engine service life under normal operating conditions, regular overhaul and cleaning should be carried out every 12 months or after every 1000 hours (without lubricated air) or 2000 hours (with lubricated air) of operation, whichever is the sooner. Overhaul should be carried out more frequently under more rigorous operating conditions.

Clean the engine thoroughly.
Fit the engine and check that it rotates freely. Pour two drops of oil into the air intake and idle the engine for 5–10 seconds.

If the compressed air is very dry, the idle speed for lubricant-free engines may decrease slightly after fairly long periods of operation. This decrease may amount to 10–15%.