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Rotax 912ULS is aging like a Fine Wine…

Piper J3

Well Known Member
My early SN 120058 RV-12 now has over 600TT with 912ULS manufactured in 2009. I have flown all the hours except the first 50 which were accumulated by the original builder. I use 93E10 fuel purchased from Costco exclusively (top tier refinery). Early-on, I used AeroShell Sport Plus 4 for a couple of oil changes and then switched to Mobil 1 Racing™ 4T 10W-40 full synthetic oil. The last 400 hours are all Mobil 1 with oil/filter changes every 75 hours.

What prompts me to start this thread is oil consumption is remarkably low. When I change oil, I set aside a fresh bottle of Mobil 1 to be used for replenishment during the 75 hours between oil changes. This gives me a visual reference and running total for my oil consumption. This last 75 hours has only required ½ bottle of oil. Cruise flight is always at, or very near, 5500 RPM and aircraft meets, or exceeds, Van’s published performance specifications.

So, that brings me back to the title of this thread – “Rotax 912ULS is aging like a Fine Wine”.
 
2012 build 120212

One oil and filter change at 193 hours. I think I am at 217 hours now. Call it 24 hours Hobbs. Most flights 1 to 1.4 hours long. I just added 100 ml make up, of Mobil 1 Racing 4T 10w-40 motor cycle oil, to top off the dip stick.

If I make 50 hours at same rate, and change at 75 to 80 hours, that will probably be about 1/4 of a quart added through the hottest months of summer possible.

Weather here in So CA is getting cooler, so I expect less oil temp excursions into the yellow portion of the oil temp ranges, above 230F, and less oil consumption also. Time will tell.

Fuel has been almost 100% Costco 91 octane Premium with undetectable amounts of ethanol in the fuel, so far. Tanker filling up the in ground tanks told me he'd been doing runs from the Conoco refinery to this Costco. I believe they go through 15 to 20,000 gallons of Regular, per day, there. That's at least 3 tankers worth. Premium makes up about 12 to 15% of their volume in sales. This is in City of Los Angeles, right by Interstate 5. :eek:

No lead dingle balls on any of all 8 spark plugs, when fueled this way.

I'd be most interested in hearing how Cammie Patch is doing with her fleet of RV-12's using this oil, at her flight school, Glass Cockpit Aviation.
 
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Mine just turned 618TT on my 912ULS built in 2009. I too am using Mobil 1 full synthetic. However I am losing oil out the vent tube. The oil is clean but noticeable on the bottom of the belly. When the level gets to the end of the indicator on the stick I fill it back to about halfway. This is usually only about 3 or 4 hours of runtime that I have to add oil. Is anybody else needing to add oil due to venting out the vent tube?
 
My 912ULS

I have over 1,400 hours. Nothing has changed. Change oil at 100 hours. Never had a drop of 100LL. I think the engine is good for 2,500 - 3,000 hours, maybe more.
 
I just balanced the prop on one yesterday that has racked up 1200 hours. Runs like it did years ago during its first flight, only better. Can’t beat those engines. Balance that prop and you will really love it.
 
From the ROTAX course I got the feeling the pressed crankshaft technology is why ROTAX does not want to go beyond 2000 hour TBO. Maybe that will change with more fleet experience.
 
I ordered 12 qts of this from Pep Boys, picked up 3 or 4 days later. Good price at $9.19 a qt.

DO NOT RUN this oil with 100LL fuel. Unleaded fuel ONLY.

https://www.pepboys.com/mobil-1-racing-4t-10w-40-motorcycle-oil-1-quart/product/18634

On another note, regarding oil leaks, another RV-12 owner with 630 hours on his 2012 RV-12 build noticed that cylinders 1 and 3 valve cover gasket O-Rings had gotten "hard" and were starting to weep. Ordered a few from Lockwood Aviation. Something to keep an eye on if you're losing bit of motor oil or have some drips on the lower cowling.

He just had his gearbox rebuilt, dogs and Belleville thrust washers at 595 Hours. Felt vibrations. Run on Shell AeroSport 4 Plus, mostly Mogas fueling, 75 to 80%
 
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