I pulled the plane out for a flight, but the throttle was stuck at the idle position.  no force could move it, so I removed the throttle cable to have a look at it.  it looked good with the sheathing fully in place, no signs of heat.   again, no force could move it.  it has been hot and humid lately, so I took the throttle cable home to put in a de-humidifier.  2 hours in the de-humidifier, no change.  4 hrs in the de-humidifier and the throttle broke free and was easy to move.  time for a new throttle cable and I need to have a spare on hand.   note: this cable is 2007 vintage and 1000 hrs of operation. 
edit: after the cable has been in the house at a relative humidity of 50% for 14 hours, the cable operates perfectly with no indication of impending failure.  I thought about re-installing the cable and departing for a planned camping trip to Michigan but what if it rains?  or the cable develops another problem because of some unknown internal defect, so no.  the throttle cable is a critical safety item. I'll install a new one. 

Steve Melton
N531EM, RV9A, Superior O-320, WW 200RV prop, Slick mags, CHT 330F, EGT 1300F, B&C, 1400+ hours
Freedom and Democracy are all that really matter. 
Ride a bike, unlock the world.
https://www.rvplasticparts.com/