First oil change - some questions

Q1;

It's virtually impossible to hand start a Rotax 9 engine (hot or cold) ie its safe to crank &  "Burp" hot or cold engine. Before prop hand cranking, be sure to disarm the ignition and keep body parts outside the arc of the prop.

From this Forum; I learnt to Burp my engine after the last flight of the day. The hot oil flows more readily than when cold. I still Burp my engine before the first flight of the day (usually just 2-4 compressions required) and check cold oil level.

Before draining the oil, I will do 2-3 Burps procedures, spaced some minutes apart, to get as much oil into the tank as I can. 

Due to the usually accessible position of oil tank & drain plug, you should find it easy to avoid getting burnt by the hot oil.

You will only be removing about 3 L of oil. I use some soft aluminium (flashing), formed into a channel, below the drain plug. On my aircraft, I can mold the aluminum channel over a handy section of engine frame (you may need to find some way to suspend a funnel). I use a box, stool,etc, to bring an oil/heat resistant container close to the drain point, minimising splashin and the need to stand there holding the container.

Its a good idea to measure & record the oil quantity removed and added. (You can use a graduated cylinder or the empty AeroShell oil containers to do this). After adding oil, to top mark (Max) on dip stick, run engine to minimum 50C. Let engine cool (could be overnight) check oil level before next start - you will often find that you will need to add a small amount of oil to bring level up to Max. This small addition should be included on your refill quantity record. Knowing the quantity of oil added and subsequent top ups, will give you your engines oil consumption (one of the indications of health).

Q2;

Draining the oil from the tank/reservoir does not drain oil the oil from other parts of the system.

Inspecting the magnetic plug may see a small amount of oil spill - just clean it up when plug re installed.

The oil filter will spill a significant amount of oil. Have something to catch the spill. 

(Not required - You may prefill the new oil filter, to aid in minimising air in the system).

Do an extended Burp procedure, after inspecting magnetic plug, replacing oil & filter, to remove  small amounts of air that may have entered the system.

I hope I have been of assistance

😈

Carefully evaluate under your oil reservoir whether you have enough room to pull the plug & capture the oil without making a mess.  I forged ahead in questionable conditions & made a terrible mess when I lost control of the foldable oil “ramp” I fashioned to direct the oil to the container.  unfortunately I was on my back on a creeper.  

Instead, just disconnect the intake & output lines from the top of the tank.  Loosen the bands & lift the reservoir out through the top.  

saves replacing the crush gasket on the bottom of the tank, too.  (And yes, I had to throw the clothes away instead of risking the interior on the 1.5 hr drive home). 

Hi Rick,

WOW!

I would realy like to see how your oil tank has been installed. 

This is my Sonex Legacy about 4 years ago (there have been small changes since). Aircraft  now has Hobbs 185 flight hrs. As you can see drain plug easily accessed.

My previous aircraft ATEZ Zephyr was similar, as far as oil tank access goes.😈

Hi Carlos,

My experience it that the exact order in which you perform the removal of the components is not important. The idea is to get as much of the oil as you can back in the tank to drain out. Once the tank is drained or the filter removed, do not turn the prop any more otherwise you will draw air into the oil circuit.

I cut up a plastic milk carton to fit under the oil filter to catch the oil that spill out as you rotate it. You may have to remove the exhaust header to gain better access and you may a good quality tool to slacken it if it is tight.

Only a small amount of oil will come out from behind the magnetic plug.

You need a decent size oil pan to catch the oil from the tank, don't try an old oil container with a funnel, it will overflow since the warm oil comes out too quickly. I would also recommend raising the oil pan up on a stable platform to reduce splashing.

When you refill the tank you will need enough to replace the oil that you drained plus another 250ml to account for the oil filter. You can then top up as necessary after running the engine.

It is all relatively straightforward if you are prepared and have the correct tools.

Hello Carlos

As a number of people have pointed out get the oil warm, there is no need to get it up to fully operational temperature.  Once you have run the engine there is also no need to additionally do any turning of the prop, go ahead and drain the oil. (be ready to capture 3 liters of oil)  Once you start the drain process do not turn the prop at all until you are ready to start the engine once more.  This allows the oil pickup lines from the tank to the cooler and pump to maintain what little oil is left.  This will make it easy to avoid any air in the system.  Remove the oil filter and replace it with your new filter as shown in the maintenance manual line, MML, using a bit of oil on the gasket and I like to prefill the filter to at least 50% to reduce the air that has to be cleared when we go to start.  

Replace the gasket on the oil tank, now you can go to the step to turn the prop to "burp" the system.  

As for exact steps the checklist is just that, a check list.  The exact order is not really all that important as long as they all get done.  Naturally the oil change sequence has to follow some certain flow.  

Regarding the magnetic plug inspection, that is only required on an annual inspection.  When you remove that plug there is no oil behind it to drain out so dont worry too much about that.  Remember this is a dry sump engine.  Given that the only real messy part is to catch the oil from when you remove the oil filter.  As some have suggested a foldable tray of some type under the filter to take any oil mess from the filter so it will miss your mounts and other parts.  

Cheers