912iS Sport Engine Problem
New RV-12iS with Rotax 912iS Sport Engine. Little over 40 hours of flight time with NO problems, when during a Takeoff roll, the engine just quit. There were Low Fuel Pressure and Low Oil pressure warnings as the engine quit but then all the engine gauges were inop (red X’s). The 30 amp Gen Bus fuse and 5 amp DC power fuse were also blown.
Van’s wanted to think that it was vapor lock but why did the fuses blow? Van’s requested that we replaced the HIC which supplies power to the fuel pumps. Turns out the two fuel pumps matched an Rotax AD and got replaced.
Van’s wanted us to measure the resistance measured between the Lane A and Lane B grounds on the Rotax Fuse box. The resistance was too low but after replacing HIC is now much higher. The fuel pressure increased to normal readings of 46 psi. We ran the engine several times and had even one trip around the pattern with no problems.
The next day, I was attempting to fly the plane. Start normal. Taxi normal. Run UP Check normal until testing Lane A and Lane B. The rpm was set to 4000. When I got a warning from the Dynon Skyview, "ROTAX: LIMIT FLIGHT OP ("The Rotax engine has informed Skyview there is a problem with the engine.") but the engine continued to run however the engine gauges "RED Xed" again. I taxied back in and shut the engine down.
We checked the fuses to find the 5 AMP DC power fuse bad but this time the 30 AMP Gen Bus fuse was OK.
Now when we applied power neither of the Lanes, A or B, and neither of the fuel pumps would turn on.
We then turned on the EMS Backup Battery ON. Lane A’s red light came on and then when back out and half the engine gauges had the red “X’s” removed. Lane B appeared DEAD. Both fuel pumps ran normally.
We don't have a BUD dongle, etc. We have not be able to find anybody locally here in South CA who has one and is willing to work on the engine. We finally sent an EMAIL to ROTAX and they sent us a new name but he hasn’t responded as of yet.
I have typed in “Want to buy Rotax BUD dongle” in the Internet but nowhere have I found anyone who sells them. Does anybody have one I can use or know someone who sells them and if so, where?
My hammer (my only tool) is telling me that system which controls how Lane A and Lane B operate is now inop and may have played a part in the initial problem. My guess it is in the Rotax Fuse Box. I don’t know enough about the Engine Monitoring Computer System to think the problem may be there.
Can you help? Is there a way to test the circuits in the Rotax Fuse Box?
Do you have any idea of a Sothern CA Rotax tech or shop that can help?
From the description of the events, can you point us in the correct direction to start to fix this issue?
Thanks.
Tom "GummiBear" Gummo
USAF Retired Major and F-4G Wild Weasel Instructor Pilot
Builder / Owner of a Harmon Rocket II (RV-4 with an IO-540) 2001
Builder / Owner of a RV-12iS with an INOP Rotax 912is Sport engine 2023
Apple Valley Airport, Apple Valley, CA
Cell Phone 760 - 964 - 0229 (I am old. Text first as I tend not to answer to unknown numbers)
email: t.gummo@verizon.net
