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Burping a 912/ULS engine.

PostPosted: Tue Aug 17, 2010 7:38 pm
by Hoot
The 912ULS engine on my Savage Cub only has 62 hours on it since new. The aircraft itself also only has the same amount of time.

Several days ago I went to fly the aircraft and tried to check the oil level. I couldn't get the burp from the oil tank (lid off) no matter how many turns (counterclockwise) I turned the prop. I knew I had oil so I decided to fly the plane. Runup went good, everything in the green on my EMS-10 monitor and hardly a drop in the mag check. But in the air for 10 minutes, although my oil pressure stayed in the green, my oil pressure climbed to 278 degrees on my yellow caution indicator, just below the red Max indicator of 280. I immediately reduce throttle and landed at the airport. On the ground, I again tried to hand prop the propeller but still no burp.

The following day I again tried to burp the oil tank but no luck. Since it was a cooler morning, I took the plane up in the pattern. Oil pressure was 44 degrees and the oil temp climbed to 260 degrees and I quickly landed.

There are no Rotax qualified mechanics at my field. So I suspected that the IN LINE to the fuel tank was clogged and got one of our local mechs to check it out. but the line was clean as a whistle. He found
plently of oil both in the oil tank and in the engine, but apparently the oil wasn't moving back and forth between the engine and the oil tank to help cool the engine. My other coolant is Evans.

After calling the Serbling, Fla. Rotax wholesaler, they suggested that we check the drain line under engine we used to drain the engine oil was in the front of the engine not the one closer to the rear of the engine. We did, unfortunately, the IN LINE was installation was correct. They also suggested to make sure the oil tank was set at the right angle and height. He said that is way the factory installed it and there would be problems if it were move.

We did have the prop and water radiator replaced and changed the oil about three flying hours ago. I don't think the Rotax mech burp the tank before turning it back over to me and I didn't since we just put in fresh oil. I will try to get the Rotax mech to come down to my airport (he's 35 miles away) to check the oil tank, etc.

Has anyone experienced this lack of burping and if so, how did you correct it.

Re: Burping a 912/ULS engine.

PostPosted: Wed Aug 18, 2010 4:47 pm
by alan
Hoot,

Sorry to hear of your oil problems. I have a couple of questions. Does the mechanic that changed your oil have any Rotex experience? There is a very specific procedure that should be used to change the oil in a Rotax engine. It is quite different than all other aircraft engines. Were you there when the oil was changed so you can tell us how it was drained?

It sounds like you have air in the oil system. If the oil was drained improperly there is another procedure required to get the air out. If the mechanic doesn't know the Rotax procedure your engine has probably been seriously damaged and the mechanic will owe you a new one.

You need to find out how the mechanic changed the oil. Ask for specifics. Let us know.

Alan

Re: Burping a 912/ULS engine.

PostPosted: Sat Aug 21, 2010 1:50 am
by Hoot
Thanks for your reply. No, I wasn't there when he changed the oil but I do know he used a fluid evaculator to suck the oil out from the tank. Then he pour fresh oil in the oil tank. I do remember that he said he accidentally overfilled the oil tank at that time and again sucked an amount of oil from the tank to eliminate the overflow. The mech is young and just finished the Rotax training school. The other day at my airfield while looking at the engine with a non-rotax mech, he saw a dangling CHT probe wire discounted from the number three cylinder. I took a good close-up photo to fax to a rotax supply catalog to get the right size and the clerk showed it one of their rotax mechs and he noticed that a portion of the proble was missing. It hung just below the opening where it fits. He said the rest of the probe has probably melted inside the opening and said it looks like the engine was overheated and recommended a check of the cylinders for damage which I will do. So you might be correct about the air in the oil line. Thanks again for your help.

Re: Burping a 912/ULS engine.

PostPosted: Sun Aug 22, 2010 11:10 pm
by alan
Hoot,

Please keep us informed. We are all in this together.

Alan

Re: Burping a 912/ULS engine.

PostPosted: Thu Nov 08, 2012 7:29 am
by johnsodj
What did you find out....Does air in the oil system cause a no to slow to burp situation?