I figured out Dela's wierd (i.e. surging, romping) idle problem.  Me.  Myself.
YEEHAA!!

Upon close inspection I discovered that the connector plug from the wire
harness to the aux. air regulator was for some reason (disclaimer:  I've
_never_ touched it before) not connected.  So, I connected it.  I had to remove
the entire air intake assembly before the throttle body to get at it, but I
connected it, re-assembled it, started it, and yes, steady idle.  rock friggin'
steady.

My first 'real' engine fix.  Please excuse the excessive enthusiasm.   So, to
everyone with a surging idle, check that connection.  And those experienced
folks who think I'm a wierdo for being so excited over such a simple job, just
think back to your early days of fixing engines.  It's a fantastic experience!

Marcus Elia
'84 Westy (Dela)

p.s.:  I also discovered the next possible problem:  gasoline-scented fluid in
the air intake system from throttle through to AFM.  Not a lot, but definitely
related to my problem with 'running on' at shut-down.  Any suggestions?