My M15 is having so issues. I tried to install a 110 spring recently and it wouldnt turn it over. So we put a stronger 9.6 in it and it still wouldnt turn it over. Any ideas on the problems?
So just to clarify, the gears move, but they just don't finish the cycle? Or are you getting no noise at all? It's an M110 spring right?
I'll start with the obvious, make sure your fuse isn't blown and your batteries are fully charged.
If you reshimmed your gearbox, check and make sure your shimming isn't the issue. (you should be shimming with the case closed and the screws in and tightened)
That's all I can think of right now. Hope this helps