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Correct carb chamber fuel level

in 912 / 914 Technical Questions 9 years ago
Is there a correct fuel level for the carburetor chamber? I looked in the manual but there are no details about how much fuel should be in there when the needle closes.

One of my carbs was full and leaking, and the other was like 65% full. (55cc)

What would be the correct level?

  • Re: Correct carb chamber fuel level

    by » 9 years ago

    Sounds like the float level is off. The proper way to set the float level is to remove the carb and take the bowl off. Hold it upside down. Take a millimeter ruler and set it on the edge of the carb so the carb and ruler are sticking straight up. Next slide the ruler over so the marks are up against the carb float arms and the ruler is still sitting on the edge of the carb. The top of each arm should be 10.5mm. If they are too low or too high it affects the fuel level. You adjust the height by SLIGHTLY bending the tab that the needle valve is hanging on. Once the float arm level is set you're good to go.

    Don't mess with doing a bunch of other things. It will just cost you a lot more time. Just do the above and get it right.

    Roger Lee
    LSRM-A & Rotax Instructor & Rotax IRC
    Tucson, AZ Ryan Airfield (KRYN)
    520-349-7056 Cell

    Thank you said by: Guilherme Tomazini
      
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  • Re: Correct carb chamber fuel level

    by » 9 years ago

    Thanks a lot!
    It is at 11mm, so I guess that is not the problem.
    I filled the chamber here at home, and it didn't overfill as it happened when I tried it in the aircraft with the electric pump.
    I will try it with an electric pump here to see if the needle isn't sealing properly.
      
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  • Re: Correct carb chamber fuel level

    by » 9 years ago

    An electric pump should not raise the fuel pressure more than 1 psi over the mechanical pump. many may on see .5 psi rise. Check the carb vent tubes and make sure they are the same length and neither is in a vacuum or a high pressure area.

    Roger Lee
    LSRM-A & Rotax Instructor & Rotax IRC
    Tucson, AZ Ryan Airfield (KRYN)
    520-349-7056 Cell

    Thank you said by: Guilherme Tomazini
      
    Report
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