On the 717, the throttle keep throttling down after a few minutes of flight.
The lever on my CH Eclipse yoke is at full throttle and the lever inside the sim just throttle down after a few minutes.
If I reset the lever all the way down and put it back all the way up (full throttle), it just slowly throttle back down.
I do not experience this problem on the 737.
I have experienced this problem on BETA 0.5.3 and BETA 0.5.3.5. I have not tested in 0.5.