Figure 5-56. Checking spark plug cap security to the spark plugs. Figure 5-55. Checking the security of the air inlet filter and the  security of the carburetors to the engine. Figure 5-57. Inspecting the exhaust system by jiggling the outlet  pipe and checking the springs. the condition of exhaust system for cracks and attachment  security.  [Figure 5-57] Rotate the propeller in the proper direction only and inspect  blades for cracks or nicks. Listen and feel for smooth  operation and engine compression while rotating the  propeller. Inspect propeller attachment to the gearbox and  the gearbox attachment to the engine. Check all throttle controls for smooth operation and proper  travel and locking. Also check choke and/or primer system  for proper operation and travel. The following should be performed for a flight deck  inspection: Ensure there is clear airflow for any cooling system fan or  radiator. Ensure no insects or birds created an obstruction to  the airflow for the engine cooling system. Air cooled—rotate the propeller and ensure that the cooling  fan rotates also. Water cooled—check the coolant level to ensure there is  cooling fluid in the system. Four stroke with additional oil coolers—ensure the oil cooler  has clear airflow and that nothing is blocking it. Inspect exhaust attachment to engine, and EGT senders.  Slightly jiggle the exhaust system to inspect the springs  holding it together. All springs must be secure. Inspect  Overall, particular attention should be paid to the fuel quantity,  type/grade, and quality. Modern WSC two- and four-stroke  engines are designed to use auto gas with various octane ratings  as specified by the manufacturer for different models. If auto  gas is stored for more than 3 weeks, octane value may fall  below the recommended rating. In this situation, it is best to  drain the gas and use fresh gas. For engines designed for auto  gas, aviation gasoline (AVGAS) 100LL can be mixed and used  Ignition System  Propeller Gearbox Throttle System  Flight Deck Inspection  Cooling Systems   Fuel Exhaust Systems •  Check seat security and proper adjustment for pilot  and passenger.  •  Check seat belt attachment and seatbelt operation.  •  Inspect the gauges for security and readability.  •  Switch electrical master on and check gauges for  expected readings.  [Figure 5-58] •  Check ballistic parachute handle for security and  proper location.  5-20 •  Inspect ignition system wires to spark plugs.  •  Inspect spark plug caps and wires to CDI units to  ensure they are secure and fastened.  [Figure 5-56] •  Ensure ignition switches are turned off.