Hi Mike,

Wow, Powel River, birthplace of my '87 Westy... now residing in Campbell
River.

To your ISCU question: I had similar symptoms. Tried two different used
ones, both were 'supposed to be good. Still had the 1800-2200RPM hot idle.
ISV checked ok and was clean. Opened my OEM CU and looked for burnt
components..... nada. Spent the $$$$$ at the dealer...... idle has been rock
solid at 850. Ouch, the cost was close to $300CAN as I remember.  Look for a
part No. with suffix 393"D" as a replacement. Believe the "D" is the latest
up-date, came out on the '88/89's.

The two wires zip-tied to the hose are usually for the electric heater on
the oil breather pipe from the crank-case breather tower to the in-take boot
just before the throttle-body.
Regards Phil.Zimmerman@mail.crcn.net  87 Westy, Campbell River, B.C.