| Every 8 hours | Engine Oil Level Check | Check the engine oil level every 8 hours or daily, whichever comes first - this engine holds only 15 oz, so a low level matters quickly. |
| Every 25 hours | Air Filter | Clean the air filter and pre-cleaner every 25 hours or annually, whichever comes first; replace both annually. The 550EX uses an oiled foam filter - wash it in warm water with detergent, rinse, air dry, then lightly oil it with fresh engine oil and squeeze out the excess. Briggs foam filter part numbers for the E450-550 series are 799579 and 5434K. Service more often in dusty or dirty conditions. |
| Every 50 hours | Engine Oil & Filter | Change the engine oil after the first 5 hours, then every 50 hours or annually, whichever comes first. This engine has no oil filter and uses splash lubrication. Oil: SAE 30 at 40 degF and above, SAE 10W-30 for varying temperatures, or synthetic 5W-30 / 10W-30 for all temperatures. Capacity 15 oz. Switching to synthetic does not extend the interval. Change more often in dusty, dirty, wet, hot or hilly conditions. |
| Every 50 hours | Spark Arrester | Check the muffler and spark arrester every 50 hours or annually, whichever comes first. Clean the area around the muffler and controls, and clean the finger guard, every 8 hours or daily. |