912 oil level

[John Roman]

I've just purchased a KF III with a Rotax 912 it has the new style oil dip stick. On my preflight I found the oil level about a 1/8 " below what appears to be the operating range after hand cranking the engine. I added oil to the mid point of the operating range and after returning from a short flight I noticed oil on the planes belly and found that my oil separator bottle was full.

Did I overfill ? If so what is the correct oil level or procedure fof checking the oil level ?

Thanks
John Roman
N876KF

[Tom Waid]

Did you "burp" your engine before checking the dipstick? Page 10-15 of the Operators Manual describes this procedure. Doing this assures that most all of your oil is in the tank. This gives you a more accurate dipstick reading.

[HighWing]

John,

I agree with Tom. I suspect you didn't quite empty the crank case during your pre flight "burp". I found that with my 912 powered IV that it never used oil so topping up was not an issue and I could pretty much know the degree of burping by looking at the stick. I think in time you will find the routine with your engine as well. I found that as the engine hours increased - seating the rings -and the bypass gas volumne decreased, it took more "blades" to burp the oil - 100 blades. Did you hear the gurgling sound? When all the oil is in the tank, you will hear the bypass air gurgling in the tank. I think this is why the nickname burping came about.

Lowell

[DesertFox4]

John, I did the same thing on my first model 3 with a 912. Never used a drop between oil changes. On mine I only put in 3 quarts on an oil change. If I tried to put in the last 1/3 of a quart as stated in manual it would just blow it overboard and I'd have to clean it off the bottom of the fuselage. On a long cross country flight I'll take an extra quart of oil just in case but I've never used it.
I also usually check my oil when it's hot. I let it sit a few minutes while refueling. Lets the air dissipate out of the oil in the oil tank. Gives me a more accurate reading.

Yours sounds normal to me. Enjoy the model 3 with the Rotax. It's a blast to fly.

[John Roman]

Thanks for the help. Apparently I was turning the engine enough to "Burp" the engine. Went back to the hanger and tried again and all is ok.
Thanks again
John Roman