Read the break-in instructions that came with your engine or new cylinders. Confirm your engine manual's recommendation of straight weight or ashless dispersant mineral oil. The engine literature also specifies the oil's weight, which varies with different aircraft operating temperatures.
Purchase the mineral oil. The engine's oil capacity is marked on the oil dip stick. You can also find this information in your pilot's operating handbook, or POH. Purchase enough additional oil to top off oil levels until your first oil change. Purchase the oil at your local fixed base operations, or FBO. You can often purchase aviation oil case lots at a local oil distributor.
Service your aircraft's engine with oil. Make sure that both the dipstick and oil fill cap are secure.
Start your engine using the check list contained in your aircraft's POH. Watch the oil pressure gauge for proper oil pressure.
Perform the recommended engine break-in flight according to the engine manufacturer's or overhauler's instructions.
Change the oil. Change the oil and filter after 25 hours of flying time. Service the engine with either straight mineral oil or ashless dispersant mineral oil.
