Oil Change Instructiions

DonFromTX · #1 06-12-2017, 05:51 PM

OK, I have been changing oil for over 65 years, but thought I would check to see if my newly acquired Rotax was any different. To my dismay, although th previous owner included many manuals and papers, I can find NOTHING on changing the oil. Where should I be looking?

Jesse · #2 06-12-2017, 06:18 PM

For a simple oil change just drain and refill the tank without leaving it empty for long. With the filter also, there's a little more to it. You should be able to google some good videos about what to do with each line when you pull the can to wipe it out. If you let oil out of certain lines you have to do a pressure purge.

DHeal · #3 06-12-2017, 06:58 PM

There is a lot of information on maintaining the ROTAX 912 ULS on the following sites: 1.) www.rotax-owner.com and 2.) http://www.flyrotax.com/services/tec...mentation.html

One unique caveat regarding the 912's oil change (and in general): Do not turn the propeller backwards. That may cause air pockets to form in the various oil lines and require a "purging" of the oil system. "Purging" is not the same as the more typical "burping" of the oil system. This is all explained in the ROTAX service publications and various informational videos.

Keep in mind that the 912 is not like a Cont/Lyco/Frank -- the 912 requires specific maintenance techniques and procedures that are somewhat different from those used on traditional aircraft engines.

PilotBrent · #4 06-12-2017, 07:00 PM

Don, suggest you download the most current ROTAX MAINTENANCE MANUAL from the FlyRotax website (you want the Line Maintenance Manual) All the latest ROTAX manuals are available online and should be referenced. The site has lots of factory documents for download.

http://www.flyrotax.com/services/tec...mentation.html

Oil change is described on pg49. As mentioned, not complicated at all, but follow the torque specs etc... and you'll avoid problems later.

Better yet, 2 day service course is very worthwhile. Its not a Lycoming.

Jolly · #5 06-12-2017, 07:46 PM

Rotate the prop first to get the tank gurgle. This pushes the excess oil back to the tank from the crankcase. If you fail to do this you might over fill the tank later and just make a mess all over the asphalt. Remove the oil tank drain plug and drain the oil. Fill the tank with 3 liters of Aero Shell Sport Plus 4. The containers come in liters. Do not put in less. 3 liters fills the new oil filter and puts the level at the top of the flat area on the dipstick. Don't forget to safety wire the oil tank plug. Remove the old oil filter and install the new one. After the oil filter starts to touch the case housing rotate the oil filter 3/4 turn. You most likely won't get this without a wrench. Then remove the magnetic oil plug and look for long slivers, chunks of metal or if it looks like it has a beard. If it has a few specs here and there that is normal. There is a Rotax SB out on this with pictures. Replace the magnetic plug and safety wire. Now that every thing is back in place and oil in the tank rotate the prop approximately 20 times. This will help pre fill the oil filter and help relieve any air in the system. The Rotax oil filter has a check valve in it and can't be pre filled. Some air is okay. Now you can start the engine if you want.

Hope this helps.

DonFromTX · #6 06-12-2017, 07:58 PM

Wow, that helped a lot!! Thanks.
I am aware of the unique needs of the Rotax, and will certainly download manuals, all I can get. For today all I wanted to do is get some fresh oil and filter on it.

QUOTE=Jolly;1179976]Rotate the prop first to get the tank gurgle. This pushes the excess oil back to the tank from the crankcase. If you fail to do this you might over fill the tank later and just make a mess all over the asphalt. Remove the oil tank drain plug and drain the oil. Fill the tank with 3 liters of Aero Shell Sport Plus 4. The containers come in liters. Do not put in less. 3 liters fills the new oil filter and puts the level at the top of the flat area on the dipstick. Don't forget to safety wire the oil tank plug. Remove the old oil filter and install the new one. After the oil filter starts to touch the case housing rotate the oil filter 3/4 turn. You most likely won't get this without a wrench. Then remove the magnetic oil plug and look for long slivers, chunks of metal or if it looks like it has a beard. If it has a few specs here and there that is normal. There is a Rotax SB out on this with pictures. Replace the magnetic plug and safety wire. Now that every thing is back in place and oil in the tank rotate the prop approximately 20 times. This will help pre fill the oil filter and help relieve any air in the system. The Rotax oil filter has a check valve in it and can't be pre filled. Some air is okay. Now you can start the engine if you want.

Hope this helps.[/quote]

bruceflys · #7 06-13-2017, 05:52 AM

You presented an excellent oil change process outline, Jolly. But just to be sure, I would emphasize that the oil system should be open at only one place at a time. The tank should be connected and contain oil while changing the filter. The filter should be in place while draining and refilling the tank. Otherwise air will enter the oil circuit, which then requires the pressure purging process.

Jolly · #8 06-13-2017, 08:09 AM

Hi Bruce,

You can drain the oil tank and then remove the oil filter and you will not loose any more oil. The reason for this is the oil pump design. It will not allow any significant oil volume other than a little oozing to come through the pump. If oil could flow through the pump on its own then there would be no reason to turn the prop to turn the oil pump during an oil purge. You can test this by draining the tank and removing the filter after it is drained. Then try it your way. The small oil loss at the filter will not change. Then when you put the oil and filter back in play and "Vent" the system by rotating the prop it will fill the oil filter and help purge the small amount of air in the system. The air introduction at this point is small. I typically have my new oil filter ready to screw on when I remove the old one to just help keep the oil drool mess to a minimum.
Here's another thing I learned on the Rotax forum. When you want to pull and clean the tank you can disconnect the fittings on top of the oil tank and just put a rubber stopper in the so they don't lose any oil if they hang down. The system will not lose any more oil than a regular oil change because the oil drains from the fittings anyway. Then you can replace the tank, connect the oil fittings and fill the tank with oil and do a vent like you do for a regular oil change.
No reason for an oil purge. Purging and venting are two different things as spelled out in Rotax SB's.

bruceflys · #9 06-14-2017, 06:27 AM

I take your point, Jolly, and thanks. The caution I expressed was repeated several times in a Rotax maintenance course that I took a few years ago. Perhaps the instructor feared inadvertent prop turning while the oil circuit was open at two places, which would introduce air.

Driftdown · #10 06-14-2017, 08:09 AM

Quote:

Originally Posted by Jolly

. . . "You can drain the oil tank and then remove the oil filter and you will not loose any more oil. The reason for this is the oil pump design. It will not allow any significant oil volume other than a little oozing to come through the pump. If oil could flow through the pump on its own then there would be no reason to turn the prop to turn the oil pump during an oil purge. You can test this by draining the tank and removing the filter after it is drained. Then try it your way. The small oil loss at the filter will not change. Then when you put the oil and filter back in play and "Vent" the system by rotating the prop it will fill the oil filter and help purge the small amount of air in the system. The air introduction at this point is small. I typically have my new oil filter ready to screw on when I remove the old one to just help keep the oil drool mess to a minimum.
Here's another thing I learned on the Rotax forum. When you want to pull and clean the tank you can disconnect the fittings on top of the oil tank and just put a rubber stopper in the so they don't lose any oil if they hang down. The system will not lose any more oil than a regular oil change because the oil drains from the fittings anyway. Then you can replace the tank, connect the oil fittings and fill the tank with oil and do a vent like you do for a regular oil change.
No reason for an oil purge. Purging and venting are two different things as spelled out in Rotax SB's."

All good stuff Jolly.
And thanks for sharing your experience on flying light sport airplanes.
Your explanation on airspeed/pitch and altitude-GS/power makes a lot of sense and works for many of us.
Looking forward to more of your tips on Rotax care and flying LSA.

I consider you a valuable resource to our forum here.