Rotax 912 Engine Oil

Tyler Hathaway wrote:

I know that some folks like to change the oil every 25 or 50 hours, depending on their use of 100LL (or not), but the manual only requires it at 50 (LL) or 100 (UL) hours, except for that very first 25h change.  MML 05–20–00, Pg 12

I'm with you, Tyler, on the 100-hour oil changes (or 50 hr with 100LL usage).  But this engine had sat for a while before I bought the plane, so I wanted to be super-cautious about the oil changes for a while.  I pulled the chip detector to check that out as well.  

Striving to be a cut above the norm.

I know what the manual says, but almost all the people I know use 25 hrs. for 100LL and 50 hrs. for 91 Oct auto fuel.

Remember the oil is like the blood in your body. Disease the blood (or oil in this instance)  and the body gets diseased or you die before your TBO. Oil changes just aren't that expensive compared to down the road increased maint. cost. Plus you own a plane which isn't always inexpensive and you can't pull over to the curb if something fails in flight. So I'm a believer in always doing what's best for the long haul and to keep me in the air especially when you're flying over the Grand Canyon in northern Arizona. :)

If you had to do a major repair on your gearbox or pulling the heads for rings or other head repair issues, how many oil changes could you do for $3800+/-. For most people a 50 hr. oil change is just once a year. For people who fly 100 hrs. a year that's only two oil changes. I have people with 3K + hours on their engines all because they do what's best. Keep your engine's blood clean. Oil doesn't break down chemically in 100 hrs. Black oil is normal. It just means it's doing one of its jobs. If you use 100LL very often then when you drain the oil you can see the gray lead in the oil. I wouldn't want the extra lead in my oil.

Wel,l except it's not just the nominal cost of the oil... every time you take something apart and have to put it back together again, things can go wrong.  It's the "don't mess with things more than you have to" theory.  If Rotax says the oil is good for 100 hours, I'm going to believe them, just like I believe pretty much all the other stuff they put in their manuals.

Roger, maybe you should run out and get a blood transfusion, just on principle...  ?

James, no question, if you have no idea how long the oil has been sitting there, it's a good idea to change it.  There's actually an expiration date on oil sitting that unopened in the bottles.  By "chip detector", do you mean the magnetic plug?

It's better to stay out in front of any pending issues than be behind the eight-ball. It's that "strive to be a cut above" motto I live by. Too many people now days just settle to be average.

"Roger, maybe you should run out and get a blood transfusion, just on principle...  ?"

It gets sampled and checked every year at my physical (a complete annual inspection)

"every time you take something apart and have to put it back together again, things can go wrong."

If you can manage to damage something in our oil change process then you shouldn't be doing it. There just isn't anything to damage here just because you drained the oil and installed a filter. It was designed just for that just like any other engine.

"I'm going to believe them, just like I believe pretty much all the other stuff they put in their manuals"

They've made mistakes in the manuals, have published service bulletins, instructions and manual revisions to fix things that were in the manuals.

Tyler Hathaway - "By "chip detector", do you mean the magnetic plug?"

Yep.  I'm an old Army helicopter pilot, and those helicopters had "chip detector warning lights" connected to "magnetic chip detectors" for every gearbox.  Apparently, all those years of training / maintaining rotorcraft just came out...