Oil leaks from tappet cover 914UL-300hours

Re: Oil leaks from tappet cover 914UL-300hours

by Fco. Javier Rodriguez » 14 years ago

Fco. Javier Rodriguez

0 2 0

I have the same nuisance on my new 912UL and would appreciate any comments. Thank you from Alicante , Spain

Re: Oil leaks from tappet cover 914UL-300hours

by Richard A Herber » 14 years ago

Richard A Herber

2 6 0

Hi Alicante

Please check in the forum under the general discussion folder- there are some replies that may help.
It seems that if you do not have a 2 mm gap between the 2 tappet covers where they meet , then the expansion from the heat and the vibration that occurs where they touch may cause leakage.
Thanks
Richard

Re: Oil leaks from tappet cover 914UL-300hours

by Ken kitzmann » 14 years ago

Ken kitzmann

0 24 16

I had a 80 hp that was ten years old with only about 30 hrs on it, that leaked enough to have to wipe valve cover every flight and it was getting all over the cylinder also, I ended up getting 2 new nuts (inside valve cover) that hold the head on and replaced them one at a time and solved it. Before that I tried new o rings and always had the gap between covers good.

Re: Oil leaks from tappet cover 914UL-300hours

by Roger Lee » 14 years ago

Roger Lee

131 5.38k 5.44k

I have experienced this on my own aircraft. You find most engines that are sealed tight and never an issue. I have seen a few that don't actually leak, but ooze a tiny bit of oil from the valve cover. I have tried to resurface the valve covers. (Easy to do) Many different sets of "O" rings and different sealers like 5910 or 574, even new valve covers and can't seem to get a handle on a few of these. I worked with a rep.from Rotax and we are stumped. We ran out of ideas. This is one place I will bow to someone that gives me a definitive solution that actually works. Some of the ideas above do work, but in a case or two did not.

---

Roger Lee
LSRM-A & Rotax Instructor & Rotax IRC
Tucson, AZ Ryan Airfield (KRYN)
520-349-7056 Cell

Re: Oil leaks from tappet cover 914UL-300hours

by Richard A Herber » 14 years ago

Richard A Herber

2 6 0

Hi All

Today I attempted a fix on the left side- took a one oversize o ring - instead of 2,5mm installed 2,778mm.
This has indeed stopped the tapped covers from leaking - all be it that i have only flown a circuit to test.
My only concern is that i may end up stressing the tappet cover and finally over time it may need replacement if it warps or fractures as a result of this over size o ring.
What can be said however is that the 2,5mm does not do the job in all cases - for whatever reason.

This weekend I have a three hour flight ahead of me so by the time monday comes I can finally advise the outcome.
Thanks
Richard Herber