Thanks Dave. Interesting fact on the -13! Do model engines get a model year like cars now?
If you use e-flites, the collective wisdom on the forum is to mount it with some sort of viration damping, like a piece of rubber between the mount and the retract, and also silicon the wire leads into the PCB. They were not designed for the vibration of glow and many have bad them fail within a few flights, particularly the nose gear.