Bill_H

Bill_H

Well Known Member
Patron
I'm looking at the rotax oil purging procedure and also the video at rotax-owner.com. Three questions:

1. It says to replace the valve cover o-rings after performing the initial purge procedure and checking that the valve lifters are properly purged. This is a $67 set of gaskets! Is anyone doing this?

2. The oil drain at the bottom of the oil tank has a crush washer. It is a $1.71 part to be replaced each change. The Rotax parts manual shows this as P/N 250010, a 12x18 (mm I assume).
If 12x18 means IDxOD, then it is 0.47" ID and 0.71 OD. That is a ring width of about 1/4 inch - wider than the AN ones linked below which are 1/8 inch.
Anyone know the AN900-XX designation for this so I can get it at AC Spruce? (AN-900-8 is 1/2 inch ID) If anyone has an uninstalled extra and can measure the ID and OD, I can figure it out at http://www.aircraftspruce.com/catalog/eppages/an900.php

3. Has anyone put on an oil quick drain? This one maybe?
http://www.aircraftspruce.com/catalog/appages/curtisquickdv47.php

Thanks, Bill
 
Bill,

The Rotax purging procedure for the RV12, IMHO is not nessessary.

Basically, double check the oil line routing. Add 3 qts of oil, remove the top spark plugs, mags off, turn the engine over with the starter looking for 40 psi in 15 seconds or so. Wait 5 mins for the starter to cool, and do it again. Do this 3 4 times. You are good to go.

Use the search and there are several threads about it.

Let me know if you have any questions.
 
Hey Bill - -

I'll add this also. ( similar to Larry ). I always drain my oil cooler also. MY CHOICE, I know. ( I also have a Thermostasis oil therm ). I mark the position of the fittings, and tighten them well. I add enough oil to have it at the top of the oil tank, almost ready to overflow out the neck. As Larry said, remove at least one set of plugs, and turn over for 5 seconds. Look at oil tank. It already should be going down. If yes, you have no serious leaks, and turn it over until you see 60 PSI ( in my case anyway ), and let it turn another 10 seconds. I then pause for maybe 30 seconds, then turn it over again to be sure it jumps up quickly in pressure, and turn it for maybe 15 more seconds. Then install the plugs and 'burp' it so you know how much more you need to add to get full. I get a COMPLETE oil change, and has worked well for years. Do what you feel comfortable with !

John Bender
 
Bill,

I figured right away that replacing that gasket every oil change was going to be an expensive nuisance. So - installed a quick drain at first oil change. (I think I bought it from Phil Lockwood at OSH.) Now I can reach under the tank and drain the oil w/o removing the lower cowl. IMHO, draining the oil cooler is not necessary, but then I am not as picky as JB!;)

John
 
Oil Purge

Bill,
Question 1. I do not recall seeing the need to change the valve cover O rings and did not change mine. Also, I witnessed a certified Rotax mechanic do the initial engine start on a friends RV-12 and he did not replace the O rings. He did find a soft lifter though, and the warranty covered replacement. This was the first one of those he had ever found.
That being said, I think that with a few hours on the engine and the O rings subjected to heat, they would need to be replaced, based on experience with the carb O rings.

Question 2. I have a few extra oil plug copper crush rings at the hangar and not convenient to measure today, but why not order them from Rotax along with a few spare O rings, like the carb to intake ones. I have been told that O rings have a shelf life. But, the O rings should keep for at least 5 years if kept in their sealed bags and out of the light, according to LEAF. Some of these O rings go on back order for weeks. It is a good idea to have the most likely ones on hand, IMHO. There is also a sealing washer on the magnetic plug that you will be checking at 25 hours, and then every annual. I would order some of those also. In other words, read ahead, be prepared.

Question 3. You can buy a lot of crush washers for the price of that quick drain. I think I would rather have the safety wired drain screw anyway.



Tony
 
Larry, I had searched the other threads and found your other post. I take it that you are not disconnecting that hose from the bottom of the crankcase back to the oil tank. Your procedure makes a lot of sense. I would also want to burp the tank at the end of the three spins and recheck the oil level.

Bill
 
Tony - good points. I'll make a list of those washers. I like the idea of the quick drain. the connector itself is drilled for safety wire and the valve spring loaded when it is in the off position. Lots of GA planes have them - our Bonanza did - makes things lots less messy. There is a story about a Piper Arrow where the owner installed a quick drain, probably a wrong type, and the retracting nose gear knocked it off causing oil loss and engine failure.

OH - I just got back from 5 hours dual in an RV-12 to get current and BFR!
 
Oil Purge!

Bill your engine is brand new and it was test run at the Rotax factory for a short period of time so I'm certain your Valve cover seals would be fine for a one time removal. Just make sure you adhere to the toqure setting when reinstalling them. You can also reuse that crush washer one time on the oil drain bolt, I did. Again adhere to the toqure setting for reinstalling. But after that I just ordered a few extras from LEAF in WI. At next oil change I'm installing a quick drain on my oil tank, just couldn't pass it up at the LEAF booth at OSH. You will also need to order a couple of new Oil filters while you are at it. I also do Oil analysis ever change. I use avlabs and buy their kits at OSH for $15 a pop. You are starting with a brand new engine so this is your chance to start off taking good care of it. Your engine has a 2000 hr TBO so it can last a life time with the right amount of care.;) You will do your first oil change at 25 hours, per the Rotax Maintenance Manual. then if you run auto gas at 50hrs. Then later if you want you can go to 100 hr oil changes or once a year which ever comes first. So in the end you wont be doing oil changes very often unless you fly like crazy.
 
Bill_H said:
Larry, I had searched the other threads and found your other post. I take it that you are not disconnecting that hose from the bottom of the crankcase back to the oil tank. Your procedure makes a lot of sense. I would also want to burp the tank at the end of the three spins and recheck the oil level.

Bill
Click to expand...

Thanks Bill, I forgot to add that step.

Top off the oil level when done. ;)
 
First Oil Change

Did my first oil and filter change today. I did install a quick drain also. It took several attempts to get oil pressure, presumably because of the filter change. I just cranked the engine three cycles of 10-15 seconds and the oil pressure finally came to life. Am I correct about the filter change being the oil pressure problem?
 
Dave12 said:
Did my first oil and filter change today. I did install a quick drain also. It took several attempts to get oil pressure, presumably because of the filter change. I just cranked the engine three cycles of 10-15 seconds and the oil pressure finally came to life. Am I correct about the filter change being the oil pressure problem?
Click to expand...

Not really a problem. I just start the engine after an oil change and the pressure comes up 1-2 seconds later than normal.
 
Oil Change and Sensor move

Did the oil change and moved the sensor to the firewall during the CI. It took about 30 seconds of cranking to get the pressure up to 60 pounds-- longer than with the sender on the engine. I did my best to get oil, not air in the line by using a squirt can to feed oil into the line from the sender end until pressure built up (Oil doesn't go through the restrictor as easily as air), First start the pressure came up to the bottom of the yellow arc for a minute or so-- never saw that before-- is that normal with the relocated sensor? Pressure is now rock steady-- no flickering numbers.

Wayne 120241/143WM
 
Normal Ops!

With the oil Sensor relocated to the firewall it takes longer for the oil pressure to come up. With OAT above 50F it will take about 10 seconds during a normal engine start for the oil pressure to come up. This will also cause the alarm for low oil pressure to sound during the first few seconds after engine start. This is the same way on factory non-rotax planes. You probably never noticed this on those airplanes because they had the old analog gauges. ;)You probably saw 60seconds because this was your first run after moving the sensor. After you fly a few times then this long delay should be gone, if not then you may still have air in the line back to the sensor. Another way to get all the air out of the line is to loosen the fitting that screws onto the sensor so oil will seep out around the threads. Then wrap the sensor and fitting in a small rag, then place the whole assembly into a plastic bag. Then run the engine for 30 second intervals with the top cowl off till an ample amount of oil has leaked out from around the threads. Then clean the sensor, tighten the fitting and mount on firewall. This whole procedure is done with the engine run long enough before hand to get the oil hot.
 
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