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5 Answers

Question on priming the engine

Asked by: 2668 views Aircraft Systems, Commercial Pilot, Flight Instructor, General Aviation, Private Pilot, Student Pilot

When we prime the engine by turning on fuel pump, pushing mixture full forward for few seconds and out, is the fuel being injected into the combustion chamber?

 

 

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5 Answers



  1. Kris Kortokrax on Oct 14, 2016

    It doesn’t matter whether you use the procedure you described for an injected engine or you pull out the plunger and push it back in on a carbureted engine, the purpose of priming is to inject raw fuel into the cylinder.

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  2. Best Answer


    Bill Zaleski on Oct 15, 2016

    Connor:

    Just to be clear. You are never directly injecting the prime into cylinder. You are introducing raw fuel into the intake port, on the stem side of the intake valve. The fuel/air mixture must still enter the cylinder only when the intake valve is open during the intake stroke. This is true of either fuel injected or carburetor type engines.

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  3. connor on Oct 16, 2016

    Before the engine start, not all intake valves are closed, aren’t they?

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  4. Bill Zaleski on Oct 16, 2016

    They are never all closed at the same time.

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  5. connor on Oct 18, 2016

    Yes, the prime is introduced to stem side and some cylinders might have intake port opened before start. right?

    So the prime may slide into the cylinder just a little bit ?

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