Engine surge/CS Spinner Install

ELEDSALL · #1 08-14-2015, 05:50 PM

Hey all,

I just finished installing my spinner and went to take it for a spin - no pun intended. At about 50 kts, the engine rpm's vacillated and the Dynon EM went off. I was going to fast to look down so I am not sure what the warning was about. I pulled back and went back to the hangar. I have 4 hours on it so far; new XP 0-360 and lightspeed. My first thought was something wrong with the engine and that the engine had lost power and regained it but then I asked the airport manager and he said it sounded like a surge.

It is possible that manually twisting the prop may have squeezed the oil out of it and allowed the engine to over rev. I did not cycle the prop prior to take off.

ChiefPilot · #2 08-14-2015, 07:16 PM

Quote:

Originally Posted by ELEDSALL

It is possible that manually twisting the prop may have squeezed the oil out of it and allowed the engine to over rev. I did not cycle the prop prior to take off.

....so maybe cycle the prop several times during runup and try it again - a fast taxi at least - and make note of any warnings?

drill_and_buck · #3 08-15-2015, 04:15 AM

Download the data logs from the Dynon EMS, identify the alarm, and review the rpm data points. You could have exceeded your rpm alarm point prior to the governor kicking in.

Walt · #4 08-15-2015, 06:30 AM

Even cycling a new prop/gov on the ground will not generally remove all the air, I warn customers after a prop R&R to expect some surging on the first take off. Really nothing to worry about as the prop pitch stop will prevent a serious overspeed. Set your EMS RPM warning to 2900 to avoid "nuisance" alarms.

ELEDSALL · #5 09-02-2015, 07:37 AM

Thanks for the replies. The issue appeared to go away. But after installing the gear leg pants and fairings I went for a test flight. After takeoff, I pulled back power to 75% and went to pull the prop back to 2,400. As soon as I started the smallest pull back the engine changed abruptly and harshly - up or down I am not sure, I think down. I immediately turned back to the airport not knowing what I had. I tried twice more to pull the prop back but had the same reaction. I was only moving it maybe 1/4 of an inch. I was able to make a good landing despite not knowing how well the prop would brake.

I am less than impressed with my current response from MT. They tell me that this is not the same unit that has had all of the surging issues and led me to believe that they do not even have repair parts for it. They offered to bench test it for about $300.00 but seemed to indicate that if someone was wrong with it they wouldn't know what to do with it. Not impressive.

The German manager says its 12 years old so maybe corrosion. It has 12 hours on it and has always been in a controlled environment. I explained to them that yes I had purchased the gov from Vans in 2006 but did not get into the air until last month. Doesn't seem to matter.

Has anybody else had a problem with the 400 series? I would appreciate your feedback. You would think that with the power of these forums, MT would step up and fix the issue. One bad flag has to be offset by a lot of expensive advertising.