Rotax 912 older oil reservoir

[Peteohms]

My Rotax 912 is an older engine from about 1991 and the oil reservoir does not have a drain plug on it. Would not do any good to have a drain plug since the reservoir practically sits on the engine and I'm sure I could not remove the plug without removing the engine.

It's a pain in the butt to remove the reservoir every time I change the oil. I'm thinking of getting a pump to suck the oil out. I know that there will be a small amount left in the tank so I thought every other oil change I would remove the reservoir.

Anyone else out there that does similar? Also do all of you purge the oil lines per Rotax recomendations after removing the reservoir?

[DesertFox4]

Pete, I'd just as soon not have a drain on the bottom of my tank. I can't get to it anyway and just another place to leak.
I never remove my tank when changing oil on my Model 4. I do change right after a flight so the oil is mostly in the tank and very hot. I remove the top without disconnecting the big oil lines. Lay the top across the top of the engine on a drip towel and dip the hot oil out with a plastic juice can with the top cut off. You have to remove the screen of course and when you get the oil down enough remove the screen tray with a long needle nose pliers as it is very hot. I then wipe out the tank nice and clean. Usually there's a little lead residue in mine from burning 100 LL. I change filter each time also . I fill the new filter about half full of new oil and quickly spin it on before much spills. This helps pick up oil pressure just a little quicker on start up. Put the top on and fill with 3 quarts of oil. If I put any more than 3 quarts in it just blows it overboard . Very messy on the bottom of the airplane.
I never spin the prop during oil changes to get the last little drop of old oil out. Maybe because I don't try to get every drop of old oil out I haven't had to purge. I've never "purged" my engine yet with my routine and never had a problem. The newer model Kitfox has much more room under the cowling than we do and the tanks are mounted lower so removing the tank is much quicker. They also have screw on tanks fittings which is nice. Mine are the old hose clamp kind.
Others will respond with their procedures so we'll both learn something new I'm sure.

[Peteohms]

Steve,

I hadn't thought about doing what you do but it makes sense. It will probably save some time. I just bought a pump from Harbor Freight so I can use it to remove the oil.

Pete

[DesertFox4]

Pete, if your pump has plastic parts any you change oil when it's hot be careful that your pump doesn't melt and burn you. This has happened to others so be careful.

[Peteohms]

I usually just warm up my engine slightly before changing oil but that is good to know.

[Slyfox]

THis is how I change my oil. I think Rotax came out with a simular procedure.

First thing I do is take the new filter and set it on my tool box and fill it with new oil.
I warm the engine, than remove the top of the oil reservour.
Remove the screen.
Take a suck gun and suck out the oil, I take an old oil bottle and set it on top the engine and put the oil in that.
When I get down to the dohicky on the bottom I take that out and put it in the oil catch bucket on the floor with the screen.
I take a nice clean lint free rag and wipe out the oil reservour.
I put the dohicky back in and the screen, I don't clean them.
I fill the reservour with new oil to the level that it was when I removed the lid .
I put the top back on the reservour.
I check my filter on my box, in fact I check a couple times to make sure it's full of new oil.
I pull off the old filter.
I put on the new filter as soon as I get the old one off.
Now comes the easy part, I get in the airplane (put it outside)and keep the mags off and turn the engine over and watch the oil pressure. If it doesn't go up within 15 seconds, I stop and let the starter cool. Generally on the first try(about 10seconds) I have pressure. I still give it a rest and try again to make sure there is for sure pressure.
Than I turn on the mags and start her up, watching the oil pressure to make darn sure there is good pressure.
After a good warm up, I recheck the oil level and adjust as needed.

How long does this take, generally about 20 minutes.

I'v done this for the last 800hrs. I change my oil every 50hrs.

Big thing is, don't remove any lines, that can be a safety thing anyway, you could forget to tight them or just by removing lines you can cause trouble.

hope this helps.

[RandyL]

Steve, good info. Are you running 100LL, and if so how much lead stuff are you finding in the bottom of the oil reservoir?

[Slyfox]

The only time I use 100LL is when I'm out of town. When I do use it I use tcp. All other times I use auto gas, even with the alky. I have all auto hoses for fuel injection and both tanks are doing just fine. Right tank is 95 vintage with creme, there is a couple spots where the creme wore off from putting fuel in, still no problems. Left tank was a new one from 2005, skystar and no creme and doing just fine. Have never found lead in the tank oil tank.

[Peteohms]

Thanks Steve for the detailed instruction. It should help simplify things for me.

[Slyfox]

Steve, I've done the mags off ,turn starter and check for oil pressure also. Not everyone can do that part though if they don't have ignition switches set up like you and I do so I didn't mention it. Good point though.

It wouldn't be very hard to put in a couple switches for the mags. It sure is nice to be able to turn them off and start the engine. I put my RV7A that way as well.