Do solenoids exhibit back EMF like motors?
There could be some small back EMF effect when the slug moves.  However, I seriously doubt that is what is causing the high voltage on closing.  There may be other effects:

Relay contacts bounce.  That means the solenoid will be disconnected multiple times even during a overall "on" operation.  These short disconnects that happen after some current has built up could cause high voltage for a short time.

Ringing.  There is inevitable capacitance in the system accross the coil.  When the coil is switched on, it is like energizing a tank circuit.  In ideal conditions, this could ring up to twice the input voltage especially with contact bounce.  In practise, the DC resistance of a solenoid is usually substantial enough to damp the system well enough, and the R and L of the solenoid dominate.

It's not really there.  The scope may be showing you things that aren't really happening at transients and especially with poor probe grounding.



I don't know what exactly is happening, except that I'm quite skeptical the EMF is really going to 200 V.  I also don't like the PTC fuse being in series for testing these things.  Try shorting it out and see what that does.  Also try putting a reverse diode immediately accross the solenoid, not at the other end of a wire or on the other side of the PTC fuse.  This should be a fast diode.