Troubleshooting and Abnormal Operation

in Light-Sport Aircraft Engines

The information in this section is for training purposes and should never be used for maintenance on the actual aircraft. Only qualified personnel (experienced two-stroke technicians) trained on this particular type of engine are allowed to carry out maintenance and repair work. If the following information regarding the remedy of the malfunction does not solve the malfunction, contact an authorized facility. The engine must not be returned to service until the malfunction is rectified. As described earlier in the text, engines require basically two essentials to run: spark and correct fuel/air mixture. The majority of problems quite often are a simple lack of one or the other.

Troubleshooting


Follow an organized method of troubleshooting. This facilitates the identification of discrepancies or malfunctions.

  • Fuel—start by checking the supply (tank), fittings (loose), filter (plugged), and float chamber (fouled).
  • Spark—check for spark at the spark plugs.

Problems of a more complex nature are best left to an engine technician. The following are examples of engine troubles and potential fixes.

Engine Keeps Running With Ignition OFF

Possible cause: Overheating of engine.
Remedy: Let engine cool down at idling at approximately 2,000 engine rpm.

Knocking Under Load

Possible cause: Octane rating of fuel too low.
Remedy: Use fuel with higher octane rating.
Possible cause: Fuel starvation, lean mixture.
Remedy: Check fuel supply.

Abnormal Operating

Exceeding the Maximum Admissible Engine Speed

Reduce engine speed. Any overage of the maximum admissible engine speed must be entered by the pilot into the logbook, stating duration and extent of over-speed.

Exceeding of Maximum Admissible Cylinder Head Temperature

Reduce engine power, setting to the minimum necessary, and carry out precautionary landing. Any exceeding of the maximum admissible cylinder head temperature must be entered by the pilot into the logbook, stating duration and extent of excess-temperature condition.

Exceeding of Maximum Admissible Exhaust Gas Temperature

Reduce engine power, setting to the minimum necessary, and carry out precautionary landing. Any exceedence of the maximum admissible exhaust gas temperature must be entered by the pilot into the logbook, stating duration and extent of excess-temperature condition.