Not sure what "limp" mode is but I assume it is half power or something like that. I would check the timer programing to see if something got a glitch. I had this happen one time when I tried to cycle the system off then on for a quick second test flight (these were only 30 sec flights so had lots of battery). I had landed and went to the ship with the ship in the stooge shut it off then right back on. This caused the timer (a Ztron) to go to default which was reverse rotation from what I had programed and it started to spin up in reverse. Luck I had it in a stooge. Check the timer setup.

Best,   DennisT

I have 139 flights on this combination, Brodak Hornet 40amp ESC, Hubin FM timer, Arrowind 2815/09 motor, 10/5 prop, 2200mah Thunder Tiger LIPO's, 10k launch RPM. The airplane is a Top Flite ARF Nobler. Lately it goes into limp mode shortly after take off. It runs in limp mode for maybe a minute then comes out of limp mode and runs like it supposed to. I've tried new batteries...any suggestions?

I had an FM-9 go bad.  Do you have a spare you could swap to test it?  I also had a Castle ESC reset itself and it had the wrong motor magnet count and battery cell count.  It did what yours is doing and ironically it was on a AFR Nobler.

Ken

Any follow up on this.  It is great to get answers for the next time or next person :-)

Thanks for the help, and sorry for the late response as I wanted to do some shop testing and some field testing. Seems the RPM was set to high. I slowed it back down to 10k and all is good. I'm not sure how it got changed.