My engine runs 100LL exclusively. I'm aware of the lead issue and changing oil. Rotax recommends 50 hours. Some say 25 hours. I have a vacumn draw system with a narrow tube that fits into the hole where the oil level stick fits. I'm thinking I can draw out the oil in the oil tank and replace with fresh oil thereby reducing the lead contamination.

To make this worthwhile I need to know is how much oil is contained in the tank after burping and can most of the oil in the tank be drawn out?

I'd perform this after a flight when all the contents in the oil are in dispersion.

PS I use TCP and operating the engine at the upper range.
  • Re: Quantity of oil in 912ULS Oil Tank

    by » one year ago

    Since there is a plate in the bottom and if you only try to suck out the oil all the lead and other contaminates will be below that plate and you will not get them out. You need to use the drain on the bottom to get a proper flush on the tank. Even the quick drain people don't get a good flush. Since you're using 100LL make it 25 hr. intervals and 200 hr. open the tank and clean it out.





    Roger Lee
    LSRM-A & Rotax Instructor & Rotax IRC
    Tucson, AZ Ryan Airfield (KRYN)
    520-574-1080 Home (TRY HOME FIRST)
    520-349-7056 Cell

    Thank you said by: Ken Ryan

  • Re: Quantity of oil in 912ULS Oil Tank

    by » one year ago

    So you only have to clean the tank every 200 hours? I saw somewhere where it recommended 100 hours. I use about 50:50 mogas/avgas. I cleaned mine last at about 75 hours and did not see much sludge.

  • Re: Quantity of oil in 912ULS Oil Tank

    by » 9 months ago

    Could someone PLEEEEASe tell me the volume of the oil in the tank (at about mid-dip stick or at high or at low...I just need some estimation of the volume of oil in that tank and can't find it ANYWHERE)  Thanks.


  • Re: Quantity of oil in 912ULS Oil Tank

    by » 9 months ago

    The ('large', 327 mm high) oil tank holds about 3.0 liters at the overflow tube.

    Smaller (older version,  305 mm high) tank holds about 2.5 liters.

    Dipstick 'low' is about 2.5 liters (large tank) or 2.0 liters (small tank), - the difference between full and 'low' reading on the dipstick is specified to be 0.5 liters...

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