Sport Pilot Talk

ShawnM wrote:I learned that anytime you "open" the oil system by removing lines to remove the tank you have to purge the oil system BEFORE you start the engine. Rotax states in their latest maintenance manual in chapter 12-20-00 section 11.6:

Purging the oil system is necessary:
-before each first start up (e.g. after overhaul)
-after maintenance work during which the lubrication system was opened and voided.
-when engine was cranked with open oil lines (e.g. during oil change).
-when oil system or oil lines were blown through with compressed air.

Removing the tank "opens" the oil system and this means it's necessary to purge the oil system. This procedure is spelled out in SI-912-018 and must be followed "meticulously" according to the manual. Starting an engine without purging it may cause damage. This is what I was taught by my old LSRMA.

Yes, I do know that but after talking to a few experienced mechanics and reading responses on rotax-owner.com this is what I got:

If you drain the tank, your oil lines are pretty much open to begin with since the tank is not pressurized , so what difference does it make if you disconnect the lines from the tank ( which you do when removing the tank ) or you don't ( which is the case when you just drain the oil ) - your oil line is exposed to air the same way in both cases , the only difference is which air it is exposed to - inside or outside the tank

The bottom line is , at this point my options are :

Do a full oil purge every time I change oil
or
Install a quick release valve -
I had that installed by my previous mechanic on his own accord. Turned out to be both unauthorized and , even more scary, there was hardly any clearance ( less than 0.5 inch ) between the valve and the muffler which caused mysterious symptoms like oil tank bottom plug eventually failing and leaking because valve was hitting the muffler on startup. Needless to say I got rid of the valve ( and change the mechanic).

Warmi wrote:
The bottom line is , at this point my options are :

Do a full oil purge every time I change oil
or
Install a quick release valve -
I had that installed by my previous mechanic on his own accord.

As you now know, Warmi, that was a really bad idea. I've had quite a few planes come to me for condition inspections or prebuys, in which the owner had opted to install a quick-drain (in SLSAs, with no Letter of Authorization from the manufacturer). I point out to my customers that this not only voids their airworthiness certificate, but makes them vulnerable to a complete loss of oil and a seized engine, should its spring fail. I generally pull the quick drain, install a proper plug and crush gasket, safety wire it, and return the quick drain to the owner when I return the plane to service. And, you'd be surprised how many times the plane comes back to me, a year later, with the quick-drain reinstalled!

drseti wrote:

Warmi wrote:
The bottom line is , at this point my options are :

Do a full oil purge every time I change oil
or
Install a quick release valve -
I had that installed by my previous mechanic on his own accord.

As you now know, Warmi, that was a really bad idea. I've had quite a few planes come to me for condition inspections or prebuys, in which the owner had opted to install a quick-drain (in SLSAs, with no Letter of Authorization from the manufacturer). I point out to my customers that this not only voids their airworthiness certificate, but makes them vulnerable to a complete loss of oil and a seized engine, should its spring fail. I generally pull the quick drain, install a proper plug and crush gasket, safety wire it, and return the quick drain to the owner when I return the plane to service. And, you'd be surprised how many times the plane comes back to me, a year later, with the quick-drain reinstalled!

Fully agree - I have no problem changing oil without the quick drain valve since the valve it is just another potential thing to go wrong but what I want to avoid is doing full oil purge when changing oil - that means, while I know how to do it and I have done it already twice , that's much more complicated setup ( got to bring the air compressor, hook up everything correctly etc ) than just oil/filter change.

Warmi wrote:Last week after changing the oil, filter etc .. I did my usual 20 prop pulls until the burp sound and then went out there to start the engine.

This is what the Rotax Line Maint Manual says about oil changes:

Step #8:
"After carrying out the oil change, the engine should be cranked by hand in the direction of engine rotation (approx. 20 turns) to completely refill the entire oil circuit."

20 turns = 20 revolutions = 60 prop pulls

Just say'in.

I practice 60 prop pulls.
YMMV.

From the service instructions on purging the oil system.

1.5) Compliance
These inspections have to be performed
- before first engine run,
- after re-installation (e.g. after overhaul),
- after lubrication system opened and drained during maintenance work (e.g. removal of oil
pump, oil cooler or suction line).
NOTE: Not affected are the removal and replacement of components that do not drain the oil
pressure galleries.

Opening the system to remove and clean the tank does not meet the criteria for requiring a pressure purge per the SI. Removing the tank does not drain the oil pressure galleries. The key to the requirement is draining of the oil system.

drseti wrote:

Warmi wrote:
The bottom line is , at this point my options are :

Do a full oil purge every time I change oil
or
Install a quick release valve -
I had that installed by my previous mechanic on his own accord.

As you now know, Warmi, that was a really bad idea. I've had quite a few planes come to me for condition inspections or prebuys, in which the owner had opted to install a quick-drain (in SLSAs, with no Letter of Authorization from the manufacturer). I point out to my customers that this not only voids their airworthiness certificate, but makes them vulnerable to a complete loss of oil and a seized engine, should its spring fail. I generally pull the quick drain, install a proper plug and crush gasket, safety wire it, and return the quick drain to the owner when I return the plane to service. And, you'd be surprised how many times the plane comes back to me, a year later, with the quick-drain reinstalled!

Actually, if "the spring fails," it fails to the closed position. In normal operation, in order to open the quick drain valve, the spring tension must be manually overcome and repositioned (locked) to the open position (in order to drain oil). Spring failure, the valve stays put.

Note: If the airplane is E-LSA, LOA is not required to install a quick drain, nor does it, necessarily, leave the Experimental airplane in an "unsafe" condition. That withstanding, of course, I agree it would void the Rotax engine warranty.

I have the Saf-Air quick drain and love it. I'd never go back to the old way, this is far too convenient and a lot less messy. As far as it failing, I added a rubber bolt cap I purchased on the aviation isle at Home Depot to the bottom nipple and wrapped it with a wire tie as a safety measure. It's been like this for years and has never let me down. YMMV

ShawnM wrote: As far as it failing, I added a rubber bolt cap I purchased on the aviation isle at Home Depot

I'm sure you're aware that only folks who fly an ELSA or E-AB are allowed to shop that aisle.

drseti wrote:

ShawnM wrote: As far as it failing, I added a rubber bolt cap I purchased on the aviation isle at Home Depot

I'm sure you're aware that only folks who fly an ELSA or E-AB are allowed to shop that aisle.

Best post of the day!

ShawnM wrote:I have the Saf-Air quick drain and love it. I'd never go back to the old way, this is far too convenient and a lot less messy. As far as it failing, I added a rubber bolt cap I purchased on the aviation isle at Home Depot to the bottom nipple and wrapped it with a wire tie as a safety measure. It's been like this for years and has never let me down. YMMV IMG_6909 (Small) - Copy.jpg

It appears the crush washer is installed upside down and the safety wire installation has too few wraps, IAW Aerospace Standard AS567.

drseti wrote:

ShawnM wrote: As far as it failing, I added a rubber bolt cap I purchased on the aviation isle at Home Depot

I'm sure you're aware that only folks who fly an ELSA or E-AB are allowed to shop that aisle.

Yes, I am aware and I am E-LSA.

Wm.Ince wrote:

ShawnM wrote:I have the Saf-Air quick drain and love it. I'd never go back to the old way, this is far too convenient and a lot less messy. As far as it failing, I added a rubber bolt cap I purchased on the aviation isle at Home Depot to the bottom nipple and wrapped it with a wire tie as a safety measure. It's been like this for years and has never let me down. YMMV IMG_6909 (Small) - Copy.jpg

It appears the crush washer is installed upside down and the safety wire installation has too few wraps, IAW Aerospace Standard AS567.

And the wire tie is on backwards.

Guys, it's an experimental, so AC 43-13 doesn't apply.

ShawnM wrote:I have the Saf-Air quick drain and love it. I'd never go back to the old way, this is far too convenient and a lot less messy. As far as it failing, I added a rubber bolt cap I purchased on the aviation isle at Home Depot to the bottom nipple and wrapped it with a wire tie as a safety measure. It's been like this for years and has never let me down. YMMV

I hope you remove and clean the tank periodically. The quick drains are typically slightly higher than the bottom of the tank, and in my opinion they don't allow for the large rush of fluid to help carry any debris out of the tank.

3Dreaming wrote:I hope you remove and clean the tank periodically. The quick drains are typically slightly higher than the bottom of the tank, and in my opinion they don't allow for the large rush of fluid to help carry any debris out of the tank.

Totally concur, Tom.
That was a major reason I switched back to the screw-in plug. I feel it removes more lead debris than the quick drain, due to a less restricted exit path. Besides that, it drains faster and is actually a breeze to remove and re-install with my torque wrench.