----------------------------------------------------------
                           RotaxEngines-List Digest Archive
                                      ---
                     Total Messages Posted Mon 07/30/18: 1
           ----------------------------------------------------------
 
 
Today's Message Index:
----------------------
 
     1. 07:51 PM - 912 ULS sudden rough running on mag check  (Dave)
 
 
 
________________________________  Message 1  _____________________________________


Time: 07:51:06 PM PST US
From: Dave 
Subject: RotaxEngines-List: 912 ULS sudden rough running on mag check


My engine ran fine on a local flight to a neighboring airport last week.  When
leaving, I had some vibration, rough running that is not characteristic to my
engine.  I powered up the boost pump and it seemed a little better so I continued
to taxi.  Just prior to the run up area I got a few more shakes so I pulled
off to check under the cowling.  I found nothing amiss so I continued to checklist
and mag check.  My A side ran fine but B dropped 150 or so then ran fine.
I flew the 30 min flight home without incident and arriving at the hanger
did my usual shutdown mag check.  The B side shook like crazy and I could not
power through the rough running. Heres what I found.
Grounds all normal. Checking the trigger coils resistance all was normal. I took
the connectors apart and established continuity to the triggers. Checked the
coil primary side and one had no resistance, meaning two cylinders got no spark.
I used a pin and checked the white wire near the coil and got good readings.
Moved the pin 1 inch past the connector and still good. Now I removed the
pin from the connector and the wire felt limp about 1/8 below the pin at the base
of the connector boot. I dissected the wire with an exacto and sure enough
the wire was completely broken. 
I was able to repair the connection as the wire was long enough.  Put it all back
together  and it purrs like a kitten.  It actually may be smoother than it
was on more recent flights so Ill bet it was going for some time and finally gave
up the ghost.  
Perhaps this will help someone else if they experience similar issues.

Dave Alberti


 

-------------------------------------------------------------------------------------
                       Other Matronics Email List Services
-------------------------------------------------------------------------------------
Post A New Message               rotaxengines-list@matronics.com
UN/SUBSCRIBE                     http://www.matronics.com/subscription
List FAQ                         http://www.matronics.com/FAQ/RotaxEngines-List.htm
Web Forum Interface To Lists     http://forums.matronics.com
Matronics List Wiki              http://wiki.matronics.com
Full Archive Search Engine       http://www.matronics.com/search
7-Day List Browse                http://www.matronics.com/browse/rotaxengines-list
Browse Digests                   http://www.matronics.com/digest/rotaxengines-list
Browse Other Lists               http://www.matronics.com/browse
Live Online Chat!                http://www.matronics.com/chat
Archive Downloading              http://www.matronics.com/archives
Photo Share                      http://www.matronics.com/photoshare
Other Email Lists                http://www.matronics.com/emaillists
Contributions                    http://www.matronics.com/contribution
-------------------------------------------------------------------------------------

These Email List Services are sponsored solely by Matronics and through the 
generous Contributions of its members.