Engine Operation and Safety Information


Your Jett engine will give you hours of pleasure and easy operation when the operating and safety instructions are read, studied and followed in their entirety. We have a rule at Jett: If you do something over and over again, eventually something unusual will happen. Do not think you are safe because you have done something many times before!!!
Heed these instructions.

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Jett-Stream Mufflers Jett-Stream Mufflers OPERATE AND FLY SAFELY !
Remember, this is not a toy. It is an extremely powerful and dangerous piece of machinery. At these power levels, parts can and will fail. When this happens you must be in a safe position.

  1. Use safety glasses or a safety shield when starting or running your engine. Insure that all around you do the same. Hearing protection is also highly recommended.
  2. Keep all people, spectators, children and modelers at a safe distance of 20-ft. (6M) and do not allow anyone to stand in front, or to the side of your model, or engine, at any time. Engines that stop suddenly, either due to a failure, freezing, or from loading up often unseat the propeller. Propellers can explode. Propeller blades are very, very hazardous flying objects.
  3. Always stand behind your own engine when it is operating. Do not attempt to set your needle valve or operate you engine above idle when you are in front of your engine. Do not lean your face over or toward your engine when starting or setting the needle valve.
  4. Odds are, setting your needle valve is the most dangerous thing you will be doing when operating your Jett engine. We recommend the Jett remote needle valve assembly. Save your hand. Use extreme care. Sudden, unplanned movements of the airplane should be expected!! Stay clear. Set your needle on a test stand where you have control of the situation and can use extra care. It only takes a moment to kill your engine and adjust the needle a bit at a time, rather than trying to adjust with the propeller spinning. We use a piece of 3/8" tubing with a hole drilled in the side, hooked over the needle, as a remote adjuster for the test stand. Hook it between two nails to keep it from the propeller. You can always be safe and make adjustments in a hurry. Set the idle very slowly with the engine killed. (we have a 12" screwdriver) At the field, very few adjustments will be necessary unless you have an airplane problem and you can make them with the engine killed.
  5. Operate your engine on the recommended fuel and propeller. Failure to do so will void your warranty and could cause damage to your engine and create a dangerous operating situation. Do not operate your engine above its recommended maximum RPM. Always follow the operating instructions and warnings of your fuel and propeller manufacturer. Always remember that fuel is highly flammable and can burn and explode when not handled properly.
  6. Take extreme care when using nylon, fiberglass or carbon fiber composite (non-wood) propellers. They are much more dangerous than wood. They are sharper and much less likely to break when accidental contact occurs.
  7. Make sure that your engine is properly mounted in a test stand, or in a good, strong and safe motor mount. Jett engines are very powerful and good quality mounts are a must. Make sure you have all the screws in place and that they are properly tightened. Make sure that your propeller is tightened with a wrench, and not with pliers or a nutdriver.
  8. Do not clamp your engine in a vise to test run!!
  9. Model engines run hot!! You can be burned. Avoid touching the engine and muffler for several minutes after each run or flight.
  10. Never run your engine in an enclosed place or indoors. Exhaust gas can kill. Avoid prolonged exposure to exhaust fumes.
  11. Inspect your engine mount, mounting screws, propeller and propeller nut after each flight or run. Running your engine can cause vibrations that can loosen nuts, bolts and screws. Inspect your propeller for chips and cracks which may weaken its structure.
  12. Before running the engine, make sure that the throttle linkage is attached to a servo and control rod and that it is properly adjusted. The carburetor barrel should completely shut off and must rotate slightly past closed to insure that you can stop your engine quickly and safely.
  13. Make sure that a portion of the fuel line tubing is exposed such that you can safely disconnect or pinch the fuel flow in an emergency. Do not throw something into the rotating propeller or push it into the ground to stop the engine!! The resulting broken propeller and airplane parts can become dangerous flying objects and worse, the engine may not stop.
  14. Carrying or taxiing your engine and airplane while running is not recommended. It is like carrying a running chainsaw. Use extreme care and avoid sudden movements. If you must do so because of field limitations, minimize the carry or taxi distance and start your engine in a safe place away from the pits. It is not cool to have an airplane out of control.
  15. Do not fly or stand near power lines.
  16. Do not run your engine over or near loose gravel, rocks or objects. Foreign objects may be picked up by the propellers and thrown in any direction. Protect your face and eyes at all times. Inspect your propeller after each run.
  17. Take care that loose clothing, jewelry, ties, necklaces, and other items cannot get near a running propeller. Keep the battery and starter cords clear. A safe distance can become dangerous when you are sucked into the propeller. Remove loose objects from shirt pockets and other places where they may fall out.
  18. When using a spinner, inspect to insure that the edges of the spinner are not damaging your propeller. Make sure that your spinner and prop shaft are not touching any part of the aircraft. The engine may run hot and damage itself.