Jump to content
Touring Motor Gliders Association (TMGA)
Randy Roth

Maintenance Notes After Attending Rotax Maintenance Technician's Class

Recommended Posts

Randy Roth

Hello All,

Here are a few tips and I picked up while attending the Rotax Line Service tranining class in Chino, CA. last weekend. The class was sponsored by California Power Systems and taught by Ronnie Smith of South Mississippi Light Airraft ( A Rotax Master Repair Center ). Ronnie said he has personally ben involved in the overhaul of literally hundreds and hundreds of Rotax engines.

1. Best oil is a semi synthetic 10w-40 motorcycle oil. Virtually any brand will do that is available locally. Ronnie said engines that have used that type of oil show nearly no wear at the 2000 hr. tbo. Engines that have used the new Shell Sport Plus 4 oil have shown a lot of black gum deposits especially in the piston and ring area. He said he would not recommend this type of oil.

2. Oil change..... warm engine 1st, drain tank completely, (note ... new style tank baffle restricts quick drain from opening fully, you must hold it open), remove filter, with spark plugs still in so as to make crankcase pressure, turn prop until engine burps twice into oil tank, (this will remove more old oil), coat new ROTAX oil filter seal with oil and reinstall filter making sure to not over tighten and follow requirement of max. 270 degree tightening after filter seal makes contact, IMPORTANT... if spark plugs are to be removed... with them out and 3 liters of new oil in tank, hand rotate prop through about 20 revolutions, ( this will fill oil filter and bring oil to bearings prior to starting engine), if spark plugs are not to be removed, use engine starter to crank/stop, crank/stop, crank/stop so as to fill filter and bring oil to bearings prior to engine sustained running.

3. Some engines have fuel pumps made prior to mid 2012 with a gold color pump housing. There is a mandatory change for those pumps... "gold got to go". The new fuel pump part number is 881-360. New pumps are 1/2 price now and will be full price again very soon. I. E. check yours and buy now.

4. Rotax recommends 4000rpm for mag checks. (I know.. ignition systems not mags). Reasoning here is to avoid intake compensation tube masking an ignition problem at lower, say 3000rpm. Personally, 4 k seems pretty high and can more easily pick up damaging debris.

5. If you register and pay $30/year at rotaxowner.com you will receive the latest notices for your engine and serial number.

6. Torque values and locktite # requirements etc. are found in the PARTS CATALOG.

7. Recommended cruise oil temp is 190-200 degrees. Use your cowl flap!

8. 40 degree max bank angle is not an issue according to Ronnie.

9. Removing spark plugs.... Heads are relatively soft aluminum and plugs are hardened steel. When removing plugs take care not to damage head threads with carbon build up from combustion chamber. If there is any abnormal drag during removal .... use slow out/in, out/in, out/in turns to free carbon from innermost threads and thus avoiding thread damage to head. Be sure to use proper compound on plug threads when installing new spark plugs.

10. Carburetor balancing is essential for not only a smooth running / accelerating engine but also even wear on each side of the engine.

Of course all of this is just info. Please be sure to consult the appropriate Rotax publication for the engine manufactures requirements.

All in all ... a great experience. I would recommend the course to all interested.

Fly Safe, Randy # 26

Share this post

Link to post
Share on other sites
Eric Greenwell

Thanks for the course review! It sounds like something I'd like to attend in the Winter months, and I just sent an inquiry to CPS about course schedules. If anyone knows other places that offer this class, please post here or contact me.

1. I'm surprised Ronnie thinks AeroShell Sport Plus 4 is not satisfactory. It's the only one listed in Rotax's Service Instruction SI-912016-R3 as "tested and released" by Rotax. It's also what Lockwood Aviation put in my engine at the 25 hour inspection (April 2014), so they seem to think it's satisfactory.

2. The new oil tank caused some heartburn on the next two oil changes, as the quick drain Lockwood installed at the first oil change would not lock in the "drain" position. The folks that did the last change (Aircore Aviation in Arlington, WA) took the oil tank apart, discovered it's not a 912ULS oil tank, but a 912is oil tank, with a convex internal bottom plate (rather than flat like the 912ULS). Jim says that's the tank they now supply with the 912ULS engine to reduce the tank variations required.

8. "Bank angle": after talking to Jim, we decided that "tilt" might be better word, but neither of us looked up the German version of the manual.

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now